tag:blogger.com,1999:blog-63218571301434088962024-03-12T19:32:18.306-07:00Active TectonicsMostly research and commentary blog of J Ramon Arrowsmith, Professor of Geology in the School of Earth and Space Exploration at Arizona State University. Commentary, ideas, notes on active tectonics, tectonic geomorphology, earthquake geology, natural hazards, cyberinfrastructure for the geosciences, high resolution topography.J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.comBlogger105125tag:blogger.com,1999:blog-6321857130143408896.post-26664567173252275092024-03-08T22:04:00.000-08:002024-03-11T04:00:46.579-07:00Remembering Thomas C. Hanks<p>I heard that Thomas C. Hanks passed away recently. He was a mentor to me. He worked for his career with the US Geological Survey. The memorials of him from his colleagues will be many and deep. I wanted to capture some of my memories of him. Tom was very supportive of young scientists and very broad in his scientific thinking. While he was most well known as a seismologist, his work in geomorphology and fault scarps and fragile geologic features was transformative.</p>
<p><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOE1WSQf3aJkxpYMCqeLe-hS2xtPgP-cchPQYo-154qMzR9fcZXIlnkcU1AWyDHZs01BGUTbqhBoG65Ivda3MuXEnDj06mHyCPkgQqLUBEbQzQCBKeksNhgiMweVBrxi06n_OtHuLnOLF0XuDAu069nkhC2OEU2vKkQt9BvKmA05BCJrmi8F9-Ltr7T_U/s1383/2.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="777" data-original-width="1383" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOE1WSQf3aJkxpYMCqeLe-hS2xtPgP-cchPQYo-154qMzR9fcZXIlnkcU1AWyDHZs01BGUTbqhBoG65Ivda3MuXEnDj06mHyCPkgQqLUBEbQzQCBKeksNhgiMweVBrxi06n_OtHuLnOLF0XuDAu069nkhC2OEU2vKkQt9BvKmA05BCJrmi8F9-Ltr7T_U/s320/2.png"/></a></div>
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This was a sticky on a manuscript draft he once gave me after a discussion on uncertainties in morphologic datting. Look at the nice handwriting (usually from a well sharpened #2 pencil). And the signature THanks.</p>
<p>Tom was on my Ph.D. supervisory committee. I was at Stanford and Tom was in Menlo Park at the USGS. Like many of his colleagues there, he was very generous with his time with the Stanford students. We talked a lot about fault scarps and diffusion, but also about the San Andreas Fault and I was able to drive for him on a few field trips to the SAF in the southern Bay Area into the Creeping Section. With Professor Gordon Brown's support (chair of our department at the time), Tom helped to lead an active tectonics seminar one quarter.</p>
<p>Tom's work on the age of scarplike landforms from diffusion-equation analysis (title of one of his latter papers on the subject) was very influential. He teamed up with <a href="https://activetectonics.blogspot.com/2021/12/eminent-earthquake-scientists-clarence.html" target="_blank">Robert Wallace</a> and others to take something simple about how fault scarps apparently change shape over time and quantify it in a realistic way. There are numerous important papers on the topic with Tom as an author but two seminal ones are:<br>
<small>Hanks, T. C., Bucknam, R. C., Lajoie, K. R., & Wallace, R. E. (1984). Modification of wave-cut and faulting-controlled landforms. Journal of Geophysical Research. https://doi.org/10.1029/JB089iB07p05771 </small>
<br>
and<br>
<small>Hanks, T. C. (2000). The Age of Scarplike Landforms From Diffusion-Equation Analysis. https://doi.org/10.1029/rf004p0313 in Quaternary Geochronology: Methods and Applications. In AGU Reference Shelf 4 (Vol. 4). </small><br>
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Among many other contributions on the age of scarplike landforms, Tom introduced a simple morphological dating approach: reduced slope-offset. He argued for a measure of the scarp midpoint slope (reduced by the far field slope) versus the vertical offset and he developed a nice calibration along with his colleagues for the rate constant k. He favored analytical solutions (tolerating my numerical approach).
<br>
One small anecdote that I always appreciated on the geomorphology side was his desire to name a unit for GK Gilbert (1m<sup>2</sup>/kyr = 1GKG). See the seminal 1984 Hanks et al JGR paper. It did not catch on but was a fun idea. <br>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEheW2izAokr10oYWMbhPRuXfQAexo4tXlJtdyzGweUXd6vQ-Shlf5qMmQutfnaJxHQCNCBwnOZarDDHwJrL_EnTlp85OwM-NKV3EOFGSmX9IwwrgE36RcEBq8Mc909DM62rfrfJ03mLUvpzZqpPWUJNALq-fKfCCwOTPrfrw_gF1pSOqTJtbio2GlG80mg/s1185/3.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="828" data-original-width="1185" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEheW2izAokr10oYWMbhPRuXfQAexo4tXlJtdyzGweUXd6vQ-Shlf5qMmQutfnaJxHQCNCBwnOZarDDHwJrL_EnTlp85OwM-NKV3EOFGSmX9IwwrgE36RcEBq8Mc909DM62rfrfJ03mLUvpzZqpPWUJNALq-fKfCCwOTPrfrw_gF1pSOqTJtbio2GlG80mg/s320/3.png"/></a></div>
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<p>In 2007, David Haddad and I went with Tom to Northern Arizona University to see the collection of his father's photographs that he had endowed: <a href="https://library.nau.edu/speccoll/exhibits/scaexhibits/hanks/" target="_blank">Repeat Photography Site for The James J. Hanks Photographs, 1927-1928</a>. Tom, like always, was deeply engaged/obsessed with the topic at hand. He worked hard to relocate and repeat his father's photographs, as well as to tell their story.</p>
<p>Whilst on the trip to Flagstaff, Tom, David, and I stopped to see and discuss the <a href="https://maps.app.goo.gl/9zSU8by452QX5Sct9" target="_blank">Granite Dells</a> (near Prescott, AZ). Tom had been leading parts of the seismic hazard analysis for the Yucca Mountain possible nuclear repository. The problem they were coming up with was the age of the landscape was great (million year old landforms) and there were fragile geologic features and precarious rocks that may have been there fragile for a large fraction of that time. However, the extrapolation of the ground motion predictions would be to extreme, possibly unrealistic levels. Tom was interested in these million-year-old landscapes of fragile geologic features and recognized their value as an observational constraint for seismic hazard analysis. This is an impressive product of their work:<br>
<small>Hanks, T. C., Abrahamson, N. A., Baker, J. W., Boore, D. M., Board, M., Brune, J. N., Cornell, C. A., & Whitney, J. W. (2012). Extreme Ground Motions And Yucca Mountain. Extreme Ground Motions and Yucca Mountain Open-File Report 2013–1245, US Geological Survey.</small><br>
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Tom was interested in precariously balanced rocks given their use as a part of seismic hazard analysis. He thought it might be helpful for new people to get involved. So, he pulled David and I into it. He was supportive and helped generate some funds for us. That lead to a couple of nice papers lead by David. I regret that we did not have Tom as a coauthor:<br>
<small>Haddad, D. E., Akciz, S. O., Arrowsmith, J. R., Rhodes, D. D., Oldow, J. S., Zielke, O., Toke, N. A., Haddad, A. G., Mauer, J., & Shilpakar, P. (2012). Applications of airborne and terrestrial laser scanning to paleoseismology. Geosphere, 8(4). https://doi.org/10.1130/GES00701.1</small><br>
<small>Haddad, D. E., Zielke, O., Arrowsmith, J. R., Purvance, M. D., Haddad, A. G., & Landgraf, A. (2012). Estimating two-dimensional static stabilities and geomorphic settings of precariously balanced rocks from unconstrained digital photographs. Geosphere, 8(5). https://doi.org/10.1130/GES00788.1</small>
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<p>A final lesson from Tom is that senior scientists should be generous and use their privilege to do good with a minimum of self promotion. Tom was a widely appreciated mentor of younger scientists--men and women. He was also a leader who did not shy away from trying to do the right thing. Just one example relates to another senior scientist who recently passed away: Paul Tapponier. Professor Tapponier led a transformation of our understanding of continental tectonics. He favored results with relatively high slip rates and thus the inference that the deformation even in plate interiors was more plate-like. Tom supported his colleague Wayne Thatcher who had come up with a result based on geodesy for the deformation of the Asian continental interior (Thatcher W. 2007. Microplate model for the present-day deformation of Tibet. J. Geophys. Res. 112:B01401) (and that did not sit well with Paul). Zack Washburn and I had written a paper based on paleoseismology that was wishy washy and did not definitely support high or low slip rates along the Altyn Tagh (although we felt like we could not support enough earthquakes to support a high slip rate but did not want to over interpret). Tom stepped in to mediate between Wayne and Paul and consulted me as part of his preparations. Tom had the stature, the intelligence, maturity and deserved respect so that he was able to set the tone for what I gather was a productive meeting.</p>
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I ended up with a copy of Tom's USGS bio and I note the following which is a nice example of his writing and matter-of-fact approach:<br>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjO2j5wlSj1GBGX8pMGRo2nGR8Ynj_PJgfnTfVnM1MEdX41WR3kayWlWZan6C_FQ_8BLRWfZvvlDUtu6oOa-Cgjy2SZH3l6SY8p21WZZOCSjbxogtChN3uMycQGXpLmSSQ6HInz-M1u5pfA9rMqLUBt1W2wsLSd2N2c5GIo8meukGaBsUX-m_H0qqeHWK4/s2192/1.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="323" data-original-width="2192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjO2j5wlSj1GBGX8pMGRo2nGR8Ynj_PJgfnTfVnM1MEdX41WR3kayWlWZan6C_FQ_8BLRWfZvvlDUtu6oOa-Cgjy2SZH3l6SY8p21WZZOCSjbxogtChN3uMycQGXpLmSSQ6HInz-M1u5pfA9rMqLUBt1W2wsLSd2N2c5GIo8meukGaBsUX-m_H0qqeHWK4/s320/1.png"/></a></div>
</p>J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-73500194765469593002023-12-15T11:27:00.000-08:002024-01-22T00:32:20.304-08:00Open Science recognition prize at AGU 2023<p>Our <a href="https://www.opentopography.org/" target="_blank">OpenTopography</a> project was honored at this year's AGU with the <a href="https://www.agu.org/honors/open-science">Open Science Recognition prize</a>: "For outstanding contributions in cyberinfrastructure, data management, training, and outreach associated with open-access high-resolution topography." It is a great honor and nice reognition for more than 15 years of work by our team. Huge thanks to Roman DiBiase for leading the nomination and for the letter writers Mike Oskin, Paola Passalacqua, and Josh Roering.</p>
<p>Chelsea Scott and Chris Crosby made a nice presentation summarizing our efforts. The recording is here: <a href="https://eppro01.ativ.me/web/page.php?page=iframe&project=AGU23&src=https%3A%2F%2Feppro01.ativ.me%2Fsrc%2FEventPilot%2Fphp%2Fscripts%2Faguvideo.php%3Fclid%3Daguorg-fm23%2FTue_W3018_1600_215541_mlwdc7%26atvid%3Ds215541-164598%26cid%3DAGU23" target="_blank">link</a>.</p>
<p>It was also nice to meet the other winner, Tasha Snow and appreciate her efforts. In particular, I really appreciated her articulation of Open Science values (image from her presentation):<br>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhfs2JpKHfZUR6AQAIa-CUfLxWJn9Tt9gxQE0uQg3A_M-9Dsp5RKKkUoSYEsqTQQXSyH8Iq0LqXWRiDQ8aKUbAiD13Gb2v5A63-Mz-5l8DXOEKFQytQV6_8I9i7iYEC1tqJIiPuJTrJVVHCEDAQcv6DoFmUJmAhT1EfMypDoojBlOOnRsnLAx6ixVsSmNk/s3108/Screenshot%202023-12-15%20122433.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="1170" data-original-width="3108" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhfs2JpKHfZUR6AQAIa-CUfLxWJn9Tt9gxQE0uQg3A_M-9Dsp5RKKkUoSYEsqTQQXSyH8Iq0LqXWRiDQ8aKUbAiD13Gb2v5A63-Mz-5l8DXOEKFQytQV6_8I9i7iYEC1tqJIiPuJTrJVVHCEDAQcv6DoFmUJmAhT1EfMypDoojBlOOnRsnLAx6ixVsSmNk/s320/Screenshot%202023-12-15%20122433.png"/></a></div></p>
<p>The full award ceremony is recorded here: <a href="https://vimeo.com/893484418" target="_blank">link</a>.<br><br>
Here are a couple of pictures of our team:<br>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtaykdbLvvmmlq16LpwkFyGfdn8hOOIdK261fmb9qDE-SkFo7-jcXTpCUqEpn-LOxofJw5RSr8iTbPGVqybbYVnOoOxJiqOd22oHDkI7NoFRP1946wcBBo6VgPZrveJSRwaHzCSZIVMvChoZopFjmyhyJZGVqNztBOkE56UB800SYhZmYCsvla7ydYyB4/s4032/IMG_2535.JPG" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="3024" data-original-width="4032" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtaykdbLvvmmlq16LpwkFyGfdn8hOOIdK261fmb9qDE-SkFo7-jcXTpCUqEpn-LOxofJw5RSr8iTbPGVqybbYVnOoOxJiqOd22oHDkI7NoFRP1946wcBBo6VgPZrveJSRwaHzCSZIVMvChoZopFjmyhyJZGVqNztBOkE56UB800SYhZmYCsvla7ydYyB4/s320/IMG_2535.JPG"/></a></div>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiJTg5Vj2GhNrOFaXWMJpC272sJoSnSBUJiYKgO-kaNiO3QCPe6ISM76EUCfnE9PM91E2U2VIMzHygFqXJj43BcLiJcJq-qvAPYNjAmPpZCppXqwZb1Et5Tc4L4FiTXFM7rlx7jp2EMBFdG4MvhdDf5wvGX1E1JI1K-cRb2V8ZF6I-Opx7zYclJ6uBz9CU/s4032/IMG_4814.jpg" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="3024" data-original-width="4032" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiJTg5Vj2GhNrOFaXWMJpC272sJoSnSBUJiYKgO-kaNiO3QCPe6ISM76EUCfnE9PM91E2U2VIMzHygFqXJj43BcLiJcJq-qvAPYNjAmPpZCppXqwZb1Et5Tc4L4FiTXFM7rlx7jp2EMBFdG4MvhdDf5wvGX1E1JI1K-cRb2V8ZF6I-Opx7zYclJ6uBz9CU/s320/IMG_4814.jpg"/></a></div></p>
<p>Other links:<br>
OpenTopography news release: <a href="https://www.opentopography.org/news/opentopography-awarded-2023-agu-open-science-recognition-prize" target="_blank">link</a><br>
</p>
<p>
And we celebrated with the other ASU / SESE awardees (Vernon Morris and Everett Shock):<br>
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<p></p>J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-79536557494775515912023-05-14T17:00:00.010-07:002023-05-14T20:44:14.927-07:00Determining the cell size of a Digital Elevation Model from point density<p>We regulary refer to high resolution topography (HRT) as having Digital Elevation Model (DEM) pixel sizes with their edges less than 1 m. Many raster DEMs derived from airborne laser swath mapping available for example from <a href="https://www.opentopography.org/" target="_blank">OpenTopography</a> are delivered at 1m/pix. In many cases, the point density might be high enough to support even higher resolution or smaller pixels. This seems like a fairly simple question: <b>what is the recommended cell size of a DEM for a given point density?</b></p>
<p>The Langridge, et al., 2013 paper cites Hu, 2003 and suggests the following:<br>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTVUNW5sXQ_KYKKC_Hug2GQi8U0IjDjAW8BTkONdmQqGy0Ck5JPnX7cDjKMsi_jCxn8OjmOsfZQyYQKZyz56kOizMpOPaheeWXjcB25Os6hd-6be8yDNa9EO_cxPLgDd44VyKyEjLJqhM8f4Rw8mhF8B3-d_JXrCZ-GqLUPFYfSmKNpbI1MnW8cVmA/s234/Screenshot%202023-05-14%20161745.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="200" data-original-height="147" data-original-width="234" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTVUNW5sXQ_KYKKC_Hug2GQi8U0IjDjAW8BTkONdmQqGy0Ck5JPnX7cDjKMsi_jCxn8OjmOsfZQyYQKZyz56kOizMpOPaheeWXjcB25Os6hd-6be8yDNa9EO_cxPLgDd44VyKyEjLJqhM8f4Rw8mhF8B3-d_JXrCZ-GqLUPFYfSmKNpbI1MnW8cVmA/s200/Screenshot%202023-05-14%20161745.png"/></a></div>
where <i>S</i> is the estimated cell size (typically in m), <i>n</i> is the number of sample points and <i>A</i> is the area containing the sample points.<br><br>
Here is a little spreadsheet to solve this equation given <i>A</i> and <i>n</i>: <b><a href="https://docs.google.com/spreadsheets/d/1aprWe-00d2xWauyaZZDM-iRldaP9PqYIm7BbGgldR-I/edit?usp=sharing" target="_blank">link</a></b>.</p>
<p>In the trivial case, that equation can be rearranged and show that 1 point per sq. m is consistent with a 1 m DEM. That seems ok in the sense that then on average there is one point for each pixel which would be the logic of this equation. It assumes then that the points are well distributed and that whatever average for point density that we might use to estimate a cell size represents the data well. A complication is the method of DEM computation: local function or linear interpolation. An example of the local implementation is the <a href="https://github.com/OpenTopography/points2grid" target="_blank">Points2Grid tool</a> (see prototype <a href="http://lidar.asu.edu/KnowledgeBase/Notes_on_Lidar_interpolation.pdf" target="_blank">here</a> and <a href="https://opentopography.org/otsoftware/points2grid" target="_blank">here</a>). Tinning or the use of triangular irregular networks linearly interpolates between (selected) points to estimate DEM pixel elevations (see <a href="https://rapidlasso.com/blast/blast2dem/" target="_blank">blast2dem</a> for example).</p>
<p>Here are some illustrations from the <a href="https://doi.org/10.5069/G9RB72JV" target="_blank">Jemez River Basin dataset</a> cited below. These data have a stated point density of 9.68 points/sq. m and were computed within the <a href="https://www.opentopography.org/" target="_blank">OpenTopography</a> portal using the <a href="http://www.cs.unc.edu/~isenburg/tin2dem/" target="_blank">TIN approach</a>. <br>
Here is an example from a site called Sulphur Creek (1 m/pix for this Digital Surface Model, DSM):
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfkJULYYpcM7624AeSR7Htzq1vUtirXTsPMQ2XjlWMVaLW21tByewBcnSFwdiTODdMIBZgyhHgDtHvEn-qFYGUWCTpYBA3-qWFAsOsAcG2NWJCEZiaY3QmGJdeFDCYOFzIYB3KppXBq_LQ8n4YcoYzNGy9IrTEHCBAAF4BMuVaJBgCQtixo_1S5t7_/s1012/viz.tin_hillshade.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="951" data-original-width="1012" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfkJULYYpcM7624AeSR7Htzq1vUtirXTsPMQ2XjlWMVaLW21tByewBcnSFwdiTODdMIBZgyhHgDtHvEn-qFYGUWCTpYBA3-qWFAsOsAcG2NWJCEZiaY3QmGJdeFDCYOFzIYB3KppXBq_LQ8n4YcoYzNGy9IrTEHCBAAF4BMuVaJBgCQtixo_1S5t7_/s320/viz.tin_hillshade.png"/></a></div>
<br>
Here is a zoom to that site with the 1m/pix DSM hillshade and 14% of the points displayed from ArcMap. We can see the 1 m pixels and that there are a decent number (about 9.7) of points for each one. This has all of the points (all classes):
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBtowTfiMBAv87ZaUPxAv4qGh77fHZXq7cI2giurgFW6QROl_Gfd8SmZRqqbM9S34MfMZK6W7vhGVYZB1BWVT3a14uePQzCsbp16Xx3a3pC_EphqCnoE6lBgwcD9HbFT_GEaSEc-1L_L-0S1spHiPdqJPkB3nrORKK-AzObTxJZr4k2gLT98Ko6V1Q/s912/8.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="693" data-original-width="912" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBtowTfiMBAv87ZaUPxAv4qGh77fHZXq7cI2giurgFW6QROl_Gfd8SmZRqqbM9S34MfMZK6W7vhGVYZB1BWVT3a14uePQzCsbp16Xx3a3pC_EphqCnoE6lBgwcD9HbFT_GEaSEc-1L_L-0S1spHiPdqJPkB3nrORKK-AzObTxJZr4k2gLT98Ko6V1Q/s320/8.png"/></a></div>
Here is the same view but with a 0.32 m/pix (recommended resolution from equation above), but applied to the Digital Terrain Model (DTM). <b>Note this is not really correct resolution estimate because the number of points classified as ground is only about 1/5 of the total. And, this shows the ground returns only.</b>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKCZY42OX2zT4dYgIckTJdR2_R0dSfrRkwqFy7QVa-JQYx1n7BlHBHYcx8v0QeWGmbPxDy8uoPEkNkJkkLCRRYvX-iqLcSGLbRgDzzszWKHRdtFFa2sWBhArx3HICia2kNVCnBJzISQpZkXSt9OiPK-eojVDru2n2XNoEtPzp4IbSo3miLXN4uYP12/s906/9.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="702" data-original-width="906" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKCZY42OX2zT4dYgIckTJdR2_R0dSfrRkwqFy7QVa-JQYx1n7BlHBHYcx8v0QeWGmbPxDy8uoPEkNkJkkLCRRYvX-iqLcSGLbRgDzzszWKHRdtFFa2sWBhArx3HICia2kNVCnBJzISQpZkXSt9OiPK-eojVDru2n2XNoEtPzp4IbSo3miLXN4uYP12/s320/9.png"/></a></div>
Zooming in even more, we can see the big triangular facets where the TINNING algorithm spanned the data gaps in the ground classified points for this 0.32 m/pix DTM:
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKiN-Qd7A1ep3c841bv2C6hhcPrjpxez4bkmB0IU35D5kV5CM4yNWa9jpM5jMpKEaS6z9fcV0aLfgHsOkhVML7czocZ3WcnfWjYYMe0juiZm1zD_LXVlgXUv8qyhtxAYaEG-sl7L4z8Miq1QtOBZAy4DoVHEoPHW3RWJCY9DJZeJae_ZqRYlTRyQ19/s909/7.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="699" data-original-width="909" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKiN-Qd7A1ep3c841bv2C6hhcPrjpxez4bkmB0IU35D5kV5CM4yNWa9jpM5jMpKEaS6z9fcV0aLfgHsOkhVML7czocZ3WcnfWjYYMe0juiZm1zD_LXVlgXUv8qyhtxAYaEG-sl7L4z8Miq1QtOBZAy4DoVHEoPHW3RWJCY9DJZeJae_ZqRYlTRyQ19/s320/7.png"/></a></div>
Finally, zooming back out with the 1 m/pix DTM displayed, we can see that at this scale, the DTM landscape is well represented in general. We do need the interpolation by tinning across the gaps in the ground points:
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhB9AOCEdrq0vjCzF7p-Gtkl5SUu1ocUxyFJaESWy3yqSy5PDh0ZFC2HVQ3cY1oIgxxiOOskBWWAkd78eSisd3zWmEr3RMNA_a10oA40gwRk-SYy5HQDObhfGqdcqLvC4jMwNAeEVvPFIK9FtZC1wshG5i8My2GJryllfRNoSRXkYZ8jmUlxBn5c2BF/s903/10.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="693" data-original-width="903" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhB9AOCEdrq0vjCzF7p-Gtkl5SUu1ocUxyFJaESWy3yqSy5PDh0ZFC2HVQ3cY1oIgxxiOOskBWWAkd78eSisd3zWmEr3RMNA_a10oA40gwRk-SYy5HQDObhfGqdcqLvC4jMwNAeEVvPFIK9FtZC1wshG5i8My2GJryllfRNoSRXkYZ8jmUlxBn5c2BF/s320/10.png"/></a></div>
</p>
<p><b>References</b>
Hu, Y., 2003. Automated Extraction of Digital Terrain Models, Roads and Buildings Using Airborne LiDAR Data (PhD thesis). Department of Geomatics Engineering, The University of Calgary, Calgary, Alberta, Canada. <br><br>
Jemez River Basin Snow-off LiDAR Survey. Distributed by OpenTopography. https://doi.org/10.5069/G9RB72JV . Accessed: 2023-05-14<br><br>
Langridge, R.M., et al., Developing sub 5-m LiDAR DEMs for forested sections of the Alpine and Hope faults, South Island, New Zealand: Implications for structural interpretations, Journal of Structural Geology (2013), http://dx.doi.org/10.1016/j.jsg.2013.11.007
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-88027050536644858692022-06-30T18:50:00.013-07:002022-06-30T19:25:38.764-07:00A simple evolutionary model for fragile geologic features<p>The fragility of geologic features, such as precariously balanced rocks (PBRs), can be measured by a simple parameter like α. For the case of a PBR is the smallest of the angles between the vertical from the center of mass and its rocking points. In a landscape, each object will have a fragility and so the ensemble will be a fragility distribution. The controls on the initial distribution and its long term evolution will be from the environment and its history (material properties, landscape evolution (lowering), weathering, shaking, etc.). The distribution can be disturbed by an earthquake (or other loading like windstorm, human impacts, etc.) which abruptly removes features with fragility below a threshold α.</p>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdmKawRVkRkZQF-FBRuOzY3VV9QOW7tl4WH05dWYochQFjdWN-DI5ugBjsn8c8yGOqLrHHzRig9KRH0zrWtrPY6pi92cAnppP4vbf9DlYVG0eyYt1NhJdsoU79UhA-giH5qZO1QuTc9A3kXBzkK8urm4-myidSygRFDZuZaTXAcZMvTLd7ZR7i15tt/s4056/DJI_0311.JPG" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="400" data-original-height="3040" data-original-width="4056" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdmKawRVkRkZQF-FBRuOzY3VV9QOW7tl4WH05dWYochQFjdWN-DI5ugBjsn8c8yGOqLrHHzRig9KRH0zrWtrPY6pi92cAnppP4vbf9DlYVG0eyYt1NhJdsoU79UhA-giH5qZO1QuTc9A3kXBzkK8urm4-myidSygRFDZuZaTXAcZMvTLd7ZR7i15tt/s400/DJI_0311.JPG"/></a></div>
<i>Example of PBRs in Granite Dells, Arizona</i>
<p>I started to think an analogy with a fruit tree. I am not sure this is an original idea maybe I heard it somewhere. The progressive ripening of the fruit can be interrupted by a shake which will remove completely a subset of the most ripe fruit. For the case of the rocks, the ripening is a gradual decrease in fragility over time and then a fragility reset of a subset rather than removal after they are toppled in a shaking event. Ripening continues and the processes repeat over time. This simple model does not account for changing ripening rates or much variation in shaking effects other than threshold α. <b>The basic idea then for seismic hazard is that the fragility distribution at a location reflects the history of the long term ripening and episodic shaking and reset. Therefore, if we can produce fragility distributions for landscapes that otherwise comparible (ripening and threshold α), we might be able to say which has seen more recent shaking and of what severity. This does not directly address the age control for the history and this remains a significant problem.</b></p>
<p>I wrote a simple code to explore this problem with the hope that it helps us explain and isolate the basic controls on fragility distributions. See the figure below which presents the fragility distributions through the experiment.The algorithm is simple:<br>
<ul>
<li>Set up: Specify number of objects, the initial α distribution (assume normal), the ripening rate distribution (also normal; this is the loss of fragility per year), the timing of the earthquake, the threshold α, and the max time</li>
<li>Interseismic period 1: ripen α until the earthquake (begin and end are the upper two plots below)</li>
<li>Earthquake: remove α < threshold α (third plot below) and reset those α drawing from the same initial distribution (fourth plot below)</li>
<li>Interseismic period 2: ripen α until the end of the model time (final plot below)</li>
</ul>
</p>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_MgMqZQLOUKeVwgOUYpHE_yAMZ-gwIEC_Rrd0k31-qrn5__Iu-RCs5uz5GZH43J7jcoDS_JXhkdpiGtHEkjSiytQycpUJXNPGjC5xFZOPWAJogoifXwe5JAG1jeYkaiUjp2iG-Ec336qmA2aRwe70MRHGGeiGOd70pmez4K3G9ElT7baI5ULbbT84/s3174/1.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="400" data-original-height="1809" data-original-width="3174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_MgMqZQLOUKeVwgOUYpHE_yAMZ-gwIEC_Rrd0k31-qrn5__Iu-RCs5uz5GZH43J7jcoDS_JXhkdpiGtHEkjSiytQycpUJXNPGjC5xFZOPWAJogoifXwe5JAG1jeYkaiUjp2iG-Ec336qmA2aRwe70MRHGGeiGOd70pmez4K3G9ElT7baI5ULbbT84/s400/1.png"/></a></div>
<i>Fragility distributions through the experiment. Upper plot is initial α. 2nd plot is α and the end of interseismic period 1. 3rd plot shows removed objects with α < threshold α. 4th plot is reset distribution of < threshold α Note that some α results below threshold α. Lowest plot shows continued ripening until the end of the model.</i>
<p>The additional two figures show the evolution of fragility with time of a subset of the objects and a spatial view of the randomly positioned features, their fragility at the time of the earthquake, and the circled objects that failed. The evolutionary diagram helps illustrate the interruption of the more fragile features by the event while the others do not notice. The map provides an idea of the search challenge that this scenario presents.</p>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhltrz4qZtM-5FsrYbSvDg83nBJrxzn6vMIor_TgaCgL8tK9tGGINoxrj48JCjboMyzG9NGbUNvuuHTHguWSei31xBomZSCs0u2FKumxAczMyDGy0d1X2X12c7ySwS9honMkNBd-Qr6tFs6Fxczu-UJUdXrSFEKzbANW32m2fA50bpawUR2OkSa9_m/s3186/2.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="400" data-original-height="1872" data-original-width="3186" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhhltrz4qZtM-5FsrYbSvDg83nBJrxzn6vMIor_TgaCgL8tK9tGGINoxrj48JCjboMyzG9NGbUNvuuHTHguWSei31xBomZSCs0u2FKumxAczMyDGy0d1X2X12c7ySwS9honMkNBd-Qr6tFs6Fxczu-UJUdXrSFEKzbANW32m2fA50bpawUR2OkSa9_m/s400/2.png"/></a></div>
<i>Evolution of fragility of a subset of the objects. The red star indicates the time of the earthquake and the threshold α.</i>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJcnznMFkwxvBYinq1aJCrSfsqO3fDYg_wPzmHVk_faCJYqaRyWqn3iYjFDNfQSF-4uqNC44nEHPdAQo9fS8vqXhzDcIhO9rlsmaxcX3BmnLbQ4VIYldW5jYpbUuF_ltc5hfiGJBksL7BTMD4nevELdTWkeMKBZI52fFPjah8iddBJdxGvz81m8QHy/s3144/3.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="400" data-original-height="1881" data-original-width="3144" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJcnznMFkwxvBYinq1aJCrSfsqO3fDYg_wPzmHVk_faCJYqaRyWqn3iYjFDNfQSF-4uqNC44nEHPdAQo9fS8vqXhzDcIhO9rlsmaxcX3BmnLbQ4VIYldW5jYpbUuF_ltc5hfiGJBksL7BTMD4nevELdTWkeMKBZI52fFPjah8iddBJdxGvz81m8QHy/s400/3.png"/></a></div>
<i>Map view randomly positioned features, their fragility at the time of the earthquake, and the circled objects that failed.</i>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEju6mHHTgIMhGJ49b7ygupCEPI2Zd8ifYJDsGT3ZVxAtesGNEAHQx_lfggeoqzUnYUYc2Durg-DbEk9cgyzjqgSauNRnVXkuw-jihLlh9D6ra-J6_9dqVU0ngK_kC8xBixA7m3HYunWYgse5tMn81-vkQakmdPf-CrFZLnXNytkBp-yXIKSZKnLQCCT/s2196/4.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="400" data-original-height="1863" data-original-width="2196" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEju6mHHTgIMhGJ49b7ygupCEPI2Zd8ifYJDsGT3ZVxAtesGNEAHQx_lfggeoqzUnYUYc2Durg-DbEk9cgyzjqgSauNRnVXkuw-jihLlh9D6ra-J6_9dqVU0ngK_kC8xBixA7m3HYunWYgse5tMn81-vkQakmdPf-CrFZLnXNytkBp-yXIKSZKnLQCCT/s400/4.png"/></a></div>
<i>Maybe more realistic with a more sparse set of features and a lower threshold α (0.3 as opposed to 0.4 above).</i>
<p>This is just a sketch of the problem, but it is a toy model in which we can explore the importance of the distribution widths, timing of earthquake, etc.</p>
<p>The MATLAB code is in this repository: <a href="https://github.com/jrarrowsmith/MATLAB-Geomorphology">https://github.com/jrarrowsmith/MATLAB-Geomorphology</a>; make sure to get the script PBRevolution.m and functions ripenPBR.m and shakePBRs. </p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-75174463749778808952021-12-27T13:34:00.007-08:002021-12-28T08:11:23.672-08:00Eminent earthquake scientists: Clarence Allen and Robert Wallace oral histories<p>For some "light reading" over the winter break, I have enjoyed a read of oral histories of Clarence Allen (Caltech) and Robert Wallace (USGS). <br>
<a href="https://pubs.usgs.gov/of/1996/of96-260/">EARTHQUAKES, MINERALS AND ME: WITH THE USGS, 1942-1995 by Robert E. Wallace; Oral History Interviews With Stanley Scott; USGS Open-File Report 96-260</a><br>
<br>
<a href="https://www.eeri.org/images/oralhistory/allen.pdf">Connections EERI Oal History Series: Clarence Allen with interviewer Stanley Scott</a><br>
<a href="https://oralhistories.library.caltech.edu/191/1/Allen%20C.%20interview%20OHO.pdf">CLARENCE R. ALLEN (1925-2021) INTERVIEWED BY DAVID A. VALONE Caltech archives</a>. This latter one has a bit more about Caltech and is slightly less polished than the first.
</p>
<p>Maybe I at times too sentimental, but I found these personal and scientific histories throught provoking and inspiring, not only for their tellings of important steps in the history of earthquake science and service, but also for their modest, laconic, and matter of fact story telling. I am also fortunate to have substantial memories of interacting with both of them personally and also of the transition at the end of their careers and the beginning of mine (I entered graduate school at Stanford University in Fall 1989). I also appreciate the effort of<a href="https://www.eeri.org/oral-history-series"> EERI to accumulate those and other oral histories</a>. </p>
<p>One thing that comes to mind is that it would be nice to include some histories from women who have contributed in these areas. I will work on that for a future blog post.</p>
<p>Bob Wallace was inspiring as an earthquake geologist. I followed some of his work quite closely as I shared an obsession with geomorphic indicators of faulting, although certainly with less of an impact... <br>
Just a couple of examples from his papers:
<ol>
<li><a href="https://drive.google.com/file/d/1P3ZQYEqaP7DiG0oTtjUksJMRqPDd-s2E/view?usp=sharing">1949 - Wallace, R. E., Structure of a portion of the San Andreas rift in southern California: Bulletin of the Geological Society of America, v. 60, n. 4, p. 781-806.</a>. This is cited as one of the earliest focused mapping efforts along the San Andreas Fault. He mapped substantial offset along the San Andreas Fault and also worried about the fault zone core and interactions of the drainage network with the fault zone. At one point, I colored the detailed map to appreciate it better.</li>
<li><a href="https://drive.google.com/file/d/1P5JDUwQU-z4ypdGZ_5HAPjUskbRSDLu0/view?usp=sharing">1968 - Wallace, R. E., Notes on stream channels offset by the San Andreas fault, southern Coast Ranges, California, in Dickinson, W. R., and Grantz, Arthur, eds., Proceedings of conference on geologic problems of San Andreas fault system: Stanford University Publications in Geological Science, v. 11, p. 6-21.</a>. This was a landmark in my mind as he noted offsets along the San Andreas Fault in the Carrizo Plain as indicators of short and longer term indicators of recurrent fault slip. It was in a somewhat difficult to find publication. But, being around Stanford University (and having to move out of the Geology Corner after the Loma Prieta Earthquake), there were numerous copies to be found. Figures 6 and 7 of the histograms of numbers of channels with certain offset sizes was something we followed up on a fair bit.</li>
<li><a href="https://pubs.usgs.gov/pp/1990/1515/">1990 - Wallace, R. E., (editor) The San Andreas Fault System, California: U. S. Geological Survey Prof. Paper 1515, 283 p.</a>. This was his magnum opus. I was lucky once to meet him in his office at USGS Menlo Park and he asked if I had a copy yet. I did not even though I had stared at it. He reached into his filing cabinet and gave me his copy! I should have asked him to sign it or something but I certainly treasure that copy. It has now been rebuilt a few times...</li>
<li> <a href="https://drive.google.com/file/d/1P4F1Y8A2QjQTbeis6DgCe8R8nOtDvhw_/view?usp=sharing">1992 - Wallace, R. E., Ground-squirrel mounds and patterned ground along the San Andreas fault in central California: U. S. Geological Survey, Open-file report n.91-149, p. 1-21.</a>. This was a modest contribution, but I had a couple of conversations with him about it as we shared our enthusiasm for the Carrizo Plain. In his related GSA presentation, he even mentioned me as someone who might pick it up! Scared the crap out of me. We never really did a systematic effort on this but it remains a fascinating problem. I talk about it with people every time I get to the Carrizo Plain. </li>
</ol>
THere is a lot more to say and remember about Bob Wallace. My memories of him are also tied to Kerry Sieh who worked with Bob and honored him by naming the offset channel he explored in the 1968 paper "Wallace Creek". How many times have I read the Sieh and Jahns 1984 paper: <a href="https://drive.google.com/file/d/1P707ZlkLEJl_IFwXBfd66in-5so_UsFM/view?usp=sharing">Sieh, K. E., and Jahns, R. H. (1984). Holocene activity of the San Andreas fault at Wallace Creek, California. Geological Society of America Bulletin, 95, 883–896.</a>. We even revisited this in our <a href="https://drive.google.com/file/d/1P8lS88UOtYbxW4lR76xls-lvy1bBCkO2/view?usp=sharing">2019 paper</a>.<br>
<div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="XTSTrDVYkOg" width="320" height="266" src="https://www.youtube.com/embed/XTSTrDVYkOg"></iframe></div>
<br>One of my San ANdreas Fault tour videos over the Carrizo Plain. Hillshades produced by me from the <a href="https://doi.org/10.5069/G97P8W9T">B4 project at OpenTopography.</a></p>
<p>I did not interact with Clarence Allen as much as I did with Bob Wallace, but I did have a few nice conversations with him. I think he was more serious in the conversations than I was. They main ones were when I was thinking about going to Caltech to work with Kerry Sieh. Clarence and I talked about science, but also about trout fishing. I regret never taking him up on an invite to fish in the San Bernardino Mountains. I think my father had fished some of the same places there around and below Lake Arrowhead or Big Bear Lake.<br>
Two papers among many I would like to highlight from Clarence:
<ol>
<li><a href="https://drive.google.com/file/d/1PLZKXm-m24KmCE5Cn3Y_oToG7O06Snwj/view?usp=sharing">Allen, C. R. (1968). The tectonic environments of seismically active and inactive areas along the San Andreas fault system. Proceedings of Conference of Geologic Problems of San Andreas Fault System, 5(1496), 70–80.</a>. This stands as an important first order characterization of the San Andreas Fault system and the recognition that the geology was an important control on the current behavior of the system. I have used Figure 1 here and there over the years when I kick of talks on the San Andreas Fault. </li>
<li><a href="https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/86/8/1041/201844/Geological-Criteria-for-Evaluating?redirectedFrom=fulltext">Geological Criteria for Evaluating Seismicity: Address as Retiring President of The Geological Society of America, Miami Beach, Florida, November 1974 CLARENCE R. ALLEN GSA Bulletin (1975) 86 (8): 1041–1057. </a>This is a classic that helps to introduce the concepts of earthquake geology and the value of the geologic record in the study of recently active faults.</li>
</ol>
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhizX45dRxwnkNRw_jeKYvHxd4f7o0VenxP02MATA8x0BuXaiW-HNrPjsi-fRsqeuJ5WCKoY8Oij3YM-sf990UsITL-JYF_46RmLkIU_2xzwDkM06RvOnmV5BcOhN0N0SUa8zhAYfkN-a5S9WwqaTEMY1_0mB3IhXEmqTvx_-WhsfmshVJvnemWZzaA=s2551" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="1961" data-original-width="2551" src="https://blogger.googleusercontent.com/img/a/AVvXsEhizX45dRxwnkNRw_jeKYvHxd4f7o0VenxP02MATA8x0BuXaiW-HNrPjsi-fRsqeuJ5WCKoY8Oij3YM-sf990UsITL-JYF_46RmLkIU_2xzwDkM06RvOnmV5BcOhN0N0SUa8zhAYfkN-a5S9WwqaTEMY1_0mB3IhXEmqTvx_-WhsfmshVJvnemWZzaA=s320"/></a></div>
My recent attempt to follow Prof. Allen's ideas about the San Andreas Fault (some edits on the caption from Mike Oskin; we made this as a prototype for a SCEC request). The geology of the plate boundary shows the SAFS progressively dismembering the former subduction system (as indicated by the paired Mesozoic metamorphic--green and granitic--red rocks) (https://ngmdb.usgs.gov/gmna/; upper panel). This framework is a first order control on the behavior of the system (lower panel): active faults (USGS and CGS 2021) and M>4 seismicity (https://earthquake.usgs.gov/earthquakes/search/) overlain on the GMRT (Ryan, et al., 2009).
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-85335596875979383872021-12-05T07:57:00.008-08:002021-12-27T12:32:47.841-08:00AI art: what does " Tectonic Geomorphic San Andreas Fault" look like?<P>I saw a link to <a href="https://app.wombo.art/" target="_blank">https://app.wombo.art/</a> on twitter and people were posting what they got out of using their research or dissertation titles as a prompt. <a href="https://twitter.com/toomanyspectra/status/1467315733503754240" target="_blank">It is pretty amazing.</a> </p>
<p>I gave it a try. My dissertation was entitled "Coupled Tectonic Deformation and Geomorphic
Degradation along the San Andreas Fault System". I tried that as well as a shorter version "Tectonic Geomorphic San Andreas Fault" with a couple of different styles. I have to ponder the results. Some of the other examples work well when there is an object more recognizeable (such as a bird or T-cell), or somehow I need to give it a more interesting prompt. But the results are interesting. I like the trading card format.</p>
<p>Later on, I saw something about how the company could sell the "art" as NFTs but I guess I am not too worried about it.</p>
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J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-18863318986794730122021-12-01T17:23:00.007-08:002021-12-01T17:23:57.304-08:00Remembering Paul J. Umhoefer<p>I recently wrote this memorial for the Geological Society of America Structural Geology and Tectonics Division (which I am now beginning my stint as chairman or soon will). That is the reason for the first person plural. </p>
<p>We heard with great sadness and shock of the passing of our dear friend and colleague Professor Paul J. Umhoefer (Northern Arizona University) in late November 2021. Some of us saw him at the 2021 GSA meeting and to lose him so soon after weighs on us.</p>
<p>Paul Umhoefer was a great scientist, mentor and teacher, and servant to his professional community and department. He was well known for his research in tectonics, basin analysis, structural geology with carefully collected field data from the western US, Baja California, and Anatolia. </p>
<p>Much of his research was done in close collaboration with his many students at NAU. He was a strong mentor who guided many of those projects to publication and the students went on to success, especially in academia and the petroleum and geo-environmental industries. His professional colleagues appreciated his guidance and invitation to join interesting projects.</p>
<p>Paul was a tireless leader in the geoscience community. He helped to propel important community initiatives, including Margins/GeoPrisms. He not only contributed synthetic ideas but was an integrator and conciliator. He was an effective chair of his department helping guide it in a time of important growth. We are grateful for this leadership in the Geological Society of America Structural Geology and Tectonics Division where he was a long time active member, proponent of GSA fellows, and had recently completed the arc of leadership of the division. </p>
<p>Along with his tireless work ethic, Paul was enthusiastic and gregarious with a big smile and a joke for his friends and colleagues delivered in his deep creaky voice. He loved to talk about ideas: geoscience, politics, sports. </p>
<p>We counted on seeing him again soon. We are sorry to lose him and our thoughts are with his family and close friends.</p>
<p>
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<i>Paul Umhoefer in one of his favorite places: the southern Baja California coast line with uplifted terraces and Tertiary sedimentary and volcanic rocks awaiting his attention (Arrowsmith photo, 2005)</i></p>
<p>--Ramon Arrowsmith (incoming Division Chair) on behalf of the Geological Society of America Structural Geology and Tectonics Division</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-87642207102562437292021-10-24T12:46:00.010-07:002022-03-02T12:33:14.597-08:00Remembering Omar Abdullah<p>I heard in late August 2021 that Omar Abdullah was killed in the unrest that is occurring in Ethiopia. I did not learn of any details but he was an embasa--a lion--and no doubt he was there defending his family and lands. He was an amazing guy that I got to know over the years working in the Afar with the Ledi Geraru Project. Others knew him better. I appreciated him very much. He was from the Hadar woreda--administrative area--but we gave him a special title: "camp specialist" so we could keep him employed even when we were working in other areas with other Afars. Even the other Afars grew to appreciate him and his sense of humor.</P>
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<i>Here are two pictures from 2002 (along with Mark Jakofsky). We can appreciate Omar's sense of fashion and poise. </i>
<p>Omar had a great sense of humor. There is a drainage called "Fat Ha'". It means big mouth in Afar. As Omar said, "like me!" He was also fascinated with our western scientist lives. He called himself "Black American." He was very friendly and happy to solve problems for the success of the project.</p>
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<i>2006 pictures including Erin DiMaggio--she and I had lots of fun with Omar over the years! </i>
<p>We probably will not be back to Ethiopia and the Afar for a while sadly given the unrest. It will be very sad when we do and we really feel the loss of Omar (and probably others of our Afar friends). May he rest in peace. He always wanted me to bring him a small radio I think so he could listen to music while he waited for us to our work. I regret never quite getting around to that.</p>
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<i>2009 and 2012 pictures including Erin DiMaggio and Matt Jungers. </i>
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<ilNice picture of Omar and Erin DiMaggio</i>J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-81375483408264752502021-06-11T10:04:00.008-07:002021-06-11T10:07:16.845-07:00NSF AC GEO Report on Portfolio Review of EAR Seismology and Geodesy Instrumentation Completed<p>In April 2021, we finished a fairly intensive project: <a href="https://www.nsf.gov/news/news_summ.jsp?cntn_id=302748&org=GEO" target="_blank">AC GEO Report on Portfolio Review of EAR Seismology and Geodesy Instrumentation</a>. I defer to that page as the official one, but I wanted to put a note here as well. </p>
<p>I was the chair of the committee, and the citation is <br><br>
Arrowsmith, J R., Brodsky, E. E., Cooper, C. M., Elliott, J. L., Fee, D., Fischer, K.M.,
Hammond, W. C., La Femina, P., Lekic, V., Wang, H., and Worthington, L. L.,
Recommendations for Enabling Earth Science Through NSF’s Geophysical Facility – A
Portfolio Review of EAR Seismology and Geodesy Instrumentation, Report to the US National
Science Foundation, April 2021.
</p>
<p>But, I want to really highlight the efforts of the entire committee! This was a really strong group that worked hard and respectfully together to come up with something we are quite proud of. It has some depth which I hope will give it shelf life. </P>
<p>Here are the rest of the Acknowledgements:<br>
Thank you to UNAVCO President Rebecca Bendick and Director of Geodetic Infrastructure
Glen Mattioli as well as IRIS President Robert Woodward and Portable Programs Manager Kent
Anderson for their rapid and thorough responses to the committee queries. Christopher Crosby
(UNAVCO) provided input on geodetic imaging. Jonathan Ajo-Franklin (Rice University), Kent
Anderson (IRIS), Jnaneshwar Das (Arizona State University), Rob Evans (WHOI), W. Steven
Holbrook (Virginia Tech), and Glen S. Mattioli (UNAVCO) kindly made themselves available
for interviews with the committee. We are grateful to Lindsay M. Martin who supported the
committee very ably as science assistant from the National Science Foundation. Finally, many
thanks to Margaret Benoit (National Science Foundation Program Director) for her careful
guidance.
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-3210086760058994892021-01-06T08:40:00.006-08:002022-02-14T11:52:45.733-08:00Salt River terraces field geology exercise and updated guide<p>The Salt River in central Arizona has a spectactular set of fluvial terraces developed along it. I have lead a number of field trips along the Salt River for outreach and most importantly for our GLG451 Field Geology I course where we use a site along the Salt River for a mapping exercise. I have recently updated the materials associated with that exercise in anticipation of this Spring's class which will include a virtual component.<br>
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</P>
<p>
<div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="jVS1usdvB-U" width="320" height="266" src="https://www.youtube.com/embed/jVS1usdvB-U"></iframe></div>
<center>Tour from ASU to the Salt River site.</center>
<div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="QMyjWNciprA" width="320" height="266" src="https://www.youtube.com/embed/QMyjWNciprA"></iframe></div><center>Drone overflight of the key sites for the exercise.</center>
</p>
<p>I built on some of the very nice writing and descriptions of Professor Pewe when I wrote up a field trip guide and ran a few field trips in the early 2000s. See this <a href="http://activetectonics.asu.edu/qgeo/" target="_blank">LINK</a>. I updated that guide and it is available here: <a href="https://drive.google.com/file/d/1frhVgPskzwQhTbc2eWl9fhkbdgpBSetJ/view?usp=sharing">Landscape and geologic history along the Salt River near Tempe and Mesa, Arizona. <i>I updated this document February 14, 2022</i></a>.
</P>
<p>Here is the assignment with many additional links and explanations: <a href="https://drive.google.com/file/d/1InBPYLJZJX4oBCm7UY0B6JLGrB4l_5kA/view?usp=sharing">Virtual Field Geology assignment for Salt River Field Geology I 2021</a>. <br>
I made a long explanation of the GIS:<div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="Xg9AjCSZmYw" width="320" height="266" src="https://www.youtube.com/embed/Xg9AjCSZmYw"></iframe></div></p>
<p>These were of great interest to Professor Troy L. Pewe of Arizona State University's Department of Geology. He moved to Arizona from Alaska and converted his research from permafrost to desert processes. I was lucky to learn from him when I first came to ASU in 1995. He took me under his wing and shared with me much of what he had learned. Most importantly, he helped me to learn the field trips and field sites he had developed and discovered. I am extremely grateful to him. I recognize Brian Gootee who was a great friend of the Pewe Family and who has preserved much of the <a href="http://www.azgs.az.gov/visualize_pewe.html">Pewe legacy at the Arizona Geological Survey</a>.<br>
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<br>Pictures from those early field trips with Prof. Pewe.
</P>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-64233750791460992562020-12-31T10:51:00.009-08:002022-09-23T13:52:09.209-07:00Exploring diffusion for hillslope changes using a spreadsheet<p>I became obsessed with diffusion erosion modeling in my <a href="http://arrowsmith410-598.asu.edu/Lectures/Lecture8/Arrowsmith_Appendix_A_1995.pdf" target="_blank">PhD work</a>. It is a simple (certainly oversimplified) way to think about how hillslopes may change over time in the absence of mass wasting, debris flow, and fluvial processes. There is a lot to say about it, but I wanted to capture a few items I recently developed. </p>
<p>Here is an explanation and assignment on the topic in my <a href="http://arrowsmith410-598.asu.edu/index.html" target="_blank">Computers in Geology class</a>: <a href="http://arrowsmith410-598.asu.edu/Lectures/Lecture8/" target="_blank">Lecture 8: Exploring diffusion using Excel</a>.</p>
<p>One of the challenges that I have had in some applications is that the computational "space" was too small in the spreadsheet, given that it is fixed. Of course this is not a problem if one dynamically determines the number of time steps for example based on a stability criterion and you do it with a for or while loop in something like Matlab. So, when I was helping Emily Apel with her senior thesis recently, I built her a big spreadsheet (seemed easier given the limited time that she had. </p>
<p>Here is the original spreadsheet with only 27 space steps and 191 time steps. It is good for teaching and quick demos: <a href="https://drive.google.com/file/d/1lxW2p8f-9MOznrPSd2srssFDuerGCf2M/view?usp=sharing">LINK to Spreadsheet</a>. <br>
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Above is the screen cap of the main interface page where the user just changes the bold cells and watches the calculations in real time.
<div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-fu1-safRaBk/X-4b7VefTzI/AAAAAAAG3ao/U3MzfUwHWNkSUHm2aQ7W1-dKTgybReRpQCLcBGAsYHQ/s1601/s2.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="1050" data-original-width="1601" src="https://1.bp.blogspot.com/-fu1-safRaBk/X-4b7VefTzI/AAAAAAAG3ao/U3MzfUwHWNkSUHm2aQ7W1-dKTgybReRpQCLcBGAsYHQ/s320/s2.png"/></a></div>
Above is the screen cap of the Model Calculation Space tab which shows the compuational engine with its fixed elevation boundary conditions and explicit centered in space and forward in time finite differences.
<br><br>
Here is the big spreadsheet with 250 space steps and 1000 time steps: <a href="https://drive.google.com/file/d/1H0gFsrlZxWQyW7vL5DSFaxXMRRv8zp4U/view?usp=sharing">LINK</a>. <br><br>
And, here is a video that I built to explain the general activity for Emily Apel, but it may be useful for others. It explains the two spreadsheets that are linked above.
<div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="XZMlIK_7Y3E" width="320" height="266" src="https://www.youtube.com/embed/XZMlIK_7Y3E"></iframe></div><br>
One of the cirtical concepts that is accessible in both of these spreadsheets is the opportunity explore not only initial step models, but also continuously displaced scenarios.
</p>
<p>Here are a few other blog posts and recent publications which might be of interest as well:
<ul>
<li><a href="https://activetectonics.blogspot.com/2017/05/one-dimensional-morphological-modeling.html" target="_blank">One dimensional morphological modeling of transport and production- limited fault scarps</a></li>
<li><a href="https://activetectonics.blogspot.com/2019/02/updated-review-of-fault-scarp-analysis.html" target="_blank">Updated review of fault scarp analysis</a></li>
<li><a href="https://activetectonics.blogspot.com/2013/12/exploring-topographic-evolution-of.html" target="_blank">Exploring the Topographic Evolution of Cinder Cones</a></li>
<li>Some of my and my colleague's papers on these topics:</li>
<ul>
<li><a href="https://drive.google.com/file/d/1zgJmXGddd9bGcoHqj5OjymI4Ky5Rs8W5/view?usp=sharing">Arrowsmith, J R. and Rhodes, D. D., Original forms and
initial modifications of the Galway Lake Road scarp formed along
the Emerson Fault during the 28 June 1992 Landers, California,
earthquake, Bulletin of the Seismological Society of
America, 84, 511-527, 1994.</a></li>
<li><a href="https://drive.google.com/file/d/1rN75y-7hD73Id1MVqIKIXT5gWrWfgqMW/view?usp=sharing">Arrowsmith, J R., Pollard, D. D., and Rhodes, D. D.,
Hillslope development in areas of active tectonics, Journal
of Geophysical Research, 101, B3, 6,255-6,275, 1996.</a>
<a href="https://drive.google.com/file/d/1lWfMLEGkO9HikEfizNkp4OuZGSs2FDf6/view?usp=sharing">Correction: Journal of Geophysical Research, 104,
B1, 805, 1999.</a></li>
<li><a href="https://drive.google.com/file/d/1zIJRiRJBYSBnFNCwcNrdlHRGohA4xxaQ/view?usp=sharing">Arrowsmith, J R., Rhodes, D. D., and Pollard, D. D.,
Morphologic dating of scarps formed by repeated slip events along the San Andreas Fault, Carrizo Plain, California, Journal of
Geophysical Research, 103, B5, 10,141--10,160, 1998.</a></li>
<li><a href="https://drive.google.com/file/d/1r2HYygiyXGUNpiVh-1ZpL2myK8fhCaP9/view?usp=sharing">Hilley, G. E., Arrowsmith, J R., Amoroso, L., The role of the interaction of normal faults and fractures on scarp morphology, Geophysical Research Letters, 28, p.
3,777-3,780, 2001</a>.</li>
<li><a href="https://drive.google.com/file/d/15gZi0z00-xyouewsM77F5YSL8Ceqavmp/view?usp=sharing">de Michieli Vitturi, M. and Arrowsmith, J R., Two dimensional nonlinear diffusive numerical simulation of geomorphic modifications to cinder cones, Earth Surface Processes and Landforms, doi:10.1002/esp.3423, 2013</a>.</li>
<li><a href="https://drive.google.com/file/d/1rH81sSrGpocRarxUFS32Z8CGKdHxmG60/view?usp=sharing">Wei Zhanyu, Arrowsmith, J R., He, H., Evaluating fluvial terrace riser degradation using LiDAR-derived topography: An example from the northern Tian Shan, China, Journal of Asian Earth Sciences, Volume 105, Pages 430-442, 2015</a>.</li
><li><a href="https://drive.google.com/file/d/11Kv7z8O5TqpUOamjufYKMC2hTrssyBwT/view?usp=sharing">Xu, J., Arrowsmith, J R, Chen, J., Schoenbohm, L. M., Li, T., Yuan, Z.,
Evaluating young fluvial terrace riser degradation using a nonlinear
transport model: With application to the Kongur Normal Fault in the Pamir,
northwest China, Earth Surface Processes and Landforms, DOI: 10.1002/esp.5022,
2020</a>.</li>
</ul>
</ul>
</p>J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-76130111907453673652020-12-15T13:22:00.010-08:002020-12-15T13:43:36.759-08:00Simple computations of scalar seismic moment and moment magnitude<p>In my classes and for research, sometimes it is useful to calculate the scalar seismic moment (M<sub>0</sub>; basically a geometric measure of the total static energy release at a 0th order). It is a function of the area of a fault that slipped times the average slip times the shear modulus of the volume. The latter is usually assumed to be 30GPa. The main challenge (after determining the parameters) is to get the units all to be the same (dimensions of Newtons and meters):</p>
<p><center><i>M<sub>0</sub>= mu*Length*Width*U_bar</i>.</center></p>
<p>And, once we have that scalar moment in Nm, then we usually want to convert it to moment magnitude (M<sub>w</sub>):</p>
<p><center><i>M<sub>w</sub> = 2/3 log10(M<sub>0</sub>) – 6</i>.</center></p>
<p>Here is a simple spreadsheet to do this calculation: <a href="https://drive.google.com/file/d/1Zus8VJAK1lfKowbsum7HULDJJRf72HF5/view?usp=sharing" target="_blank">LINK</a><br>
Here is a simple and older lecture I have used in introductory level geoscience courses: <a href="https://drive.google.com/file/d/1XTT7dgaHleeOclBzNiogCxWSpY3_ll1q/view?usp=sharing" target="_blank">LINK</a>
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-21555816064671522722020-12-13T07:16:00.008-08:002020-12-14T05:21:04.212-08:00New fast workstation and sUAS capability for School of Earth and Space Exploration course development<h1>Overview</h1>
<p>Our geoscience courses have benefited from plenty of course development, especially lately as we have moved online and virtual. I recently was able to invest <a href="https://sese.asu.edu/">SESE</a> course fees to build out our capabilities for high resolution mapping and 3D work. Javier Colunga built a nice and fast Windows workstation, and we also purchased a Mavic Pro 2 sUAS system. The descriptions are below for reference.</p>
<h1>Workstation description</h1>
<p>We have been building these "gaming" style fast desktops for a while and this latest incarnation is powerful for graphics intensive and 3D work, especially structure from motion photogrammetry (e.g., <a href="https://drive.google.com/file/d/1gd0_H4ZPKxnRA-Wv31terFY6daFHGAjE/view?usp=sharing" target="_blank">Johnson, et al., 2014</a> and <a href="https://kb.unavco.org/kb/article/gsa-2019-short-course-510-high-resolution-topography-and-3d-imaging-ii-introduction-to-structure-from-motion-sfm-photogrammetry-869.html" target="_blank">GSA short course</a>). <br>
Here is a short description of the hardware (cost approx. $5k):
<ul>
<li>CPU: Ryzen Threadripper 3970X 32-core/64-thread (with a premium cpu cooling solution)</li>
<li>Main Memory: 128GB DDR4 3600</li>
<li>Graphics Card: GeForce RTX 2080 Super</li>
<li>Storage: Samsung 1TB M.2 NVME OS drive, additional 4TB hard drive</li>
<li>Operating system: windows 10 Enterprise</li>
<li>Input: Logitech wireless keyboard and mouse</li>
<li>Monitor: HP 27 inch 1440P</li>
</ul>
Here is the main software installed:
<ul>
<li>Google Earth Pro</li>
<li>Matlab R2020a</li>
<li>Camtasia 2020</li>
<li>Cloudcompare</li>
<li>Agisoft Metashape</li>
<li>ArcGIS 10.7</li>
<li>QGIS</li>
</ul>
Here is more description, how to connect remotely, and a sign up sheet. <a href="https://docs.google.com/spreadsheets/d/1C8e6GIA0iEJwhUK4-S3GE1o_FXb6PGPn-DaVL_m0M3A/edit?usp=sharing" target="_blank">LINK</a>
<h1>sUAS description</h1>
<p>For <a href="https://sese.asu.edu/">SESE</a>, we have purchased a <a href="https://www.dji.com/mavic-2" target="_blank">DJI Mavic 2 Pro</a> (actually the FlyMore combo so it has a nice case and 3 batteries). This is a nice mapping and aerial documentation system. </p>
<p>Devin Keating has been helping to get the system into production mode. He has built a nice documentation of the system and its use. He also registered it with the FAA so we have a tail number. See this <a href="https://docs.google.com/document/d/1qHfh9daDJuwPjCbfgcVFN2JeBfr6OZjOfg51Y6LmpTY/edit?usp=sharing" target="_blank">LINK</a>. To operate it, one should have the part 107 Remote Pilot certification. And, there are <a href="https://cfo.asu.edu/unmanned-aircraft-systems">ASU oversight requirements as well</a>.</p>
<h2>Recent course related work using this type of system (and computed on the nice workstation described above):</h2>
<br>
<a href="http://activetectonics.blogspot.com/2020/11/warford-ranch-volcano-arizona-suas.html" target="_blank">Warford Ranch volcano (Arizona) sUAS mapping</a><br><br>
<a href="http://activetectonics.blogspot.com/2020/03/virtual-field-geology-exercises-for.html" target="_blank">Virtual field geology exercises for GLG451 Field Geology I Spring 2020</a><br><br>
<a href="https://drive.google.com/drive/folders/1xNmyggBDiQQyz0OgVmNUDeQdpdVzRNJF?usp=sharing" target="_blank">Material for virtual exercises for GLG452 Field Geology II at Camp Tontozona AZ</a><br><br>
<iframe width="560" height="315" src="https://www.youtube.com/embed/XfbfCadSJ2Y" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
<iframe width="560" height="315" src="https://www.youtube.com/embed/gvi3p7L-HB8" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
<iframe width="560" height="315" src="https://www.youtube.com/embed/sb3ykml44pw" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-52606284475906990342020-11-25T08:27:00.020-08:002021-10-22T17:21:30.181-07:00Warford Ranch volcano (Arizona) sUAS mapping<h1>Introduction</h1>
<p>We recently visited the Warford Ranch Volcano which is a low shield volcano that is part of the Sentinel-Arlington volcanic field of southwestern Arizona. It is about 3 million years old. It was a favorite field trip destination of <a href="https://rpif.asu.edu/greeley/" target="_blank">Prof. Ronald Greeley</a>. Shelby Cave worked on the <a href="https://repository.asu.edu/items/30006" target="_blank">Sentinel-Arlington field for her Ph.D. dissertation</a> under the supervision of Prof. Greeley and after his passing she worked with Prof. Amanda Clarke. </p>
<iframe src="https://www.google.com/maps/embed?pb=!1m14!1m12!1m3!1d28120.255543955587!2d-112.99315079840234!3d33.02590146686002!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!5e1!3m2!1sen!2sus!4v1606316292602!5m2!1sen!2sus" width="500" height="375" frameborder="0" style="border:0;" allowfullscreen="" aria-hidden="false" tabindex="0"></iframe>
<i>Google maps location for Warford Ranch (NW of Gila Bend, AZ).</i>
<p>Professor Clarke is teaching the Advanced Field Geology course and she took the group to Warford Ranch volcano to examine its volcanology. I did some UAS-mapping to help with the documentation. This blog entry presents some of the products of the overflights with our Mavic Air and Phantom 4 Pro.</p>
<h1>Oblique overviews</h1>
I flew the Mavic Air high to get some views over the volcano to assess its general form and the relation to adjacent landforms and geology.<br>
<p><div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-OtGG4k-qFN0/X76HUJhh14I/AAAAAAAGzjI/Yrq24cccgTUYXPN61QZHkcypcBxS9OVbACLcBGAsYHQ/s4056/DJI_0128.JPG" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="3040" data-original-width="4056" src="https://1.bp.blogspot.com/-OtGG4k-qFN0/X76HUJhh14I/AAAAAAAGzjI/Yrq24cccgTUYXPN61QZHkcypcBxS9OVbACLcBGAsYHQ/s320/DJI_0128.JPG"/></a></div>
<i>View to the north. The cars are lower left are in our parking spot. <a href="https://drive.google.com/file/d/1BTsQkg434jzEGfHfvhuYKyYWD7V6E5hr/view?usp=sharing" target="_blank">LINK to jpg</a></i></p>
<p><div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-WsSYrfg1IxE/X76HsCMifaI/AAAAAAAGzjQ/VlXykGAHXew8Oe4rhqsu5RTWGmP90KI0gCLcBGAsYHQ/s4056/DJI_0201.JPG" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="3040" data-original-width="4056" src="https://1.bp.blogspot.com/-WsSYrfg1IxE/X76HsCMifaI/AAAAAAAGzjQ/VlXykGAHXew8Oe4rhqsu5RTWGmP90KI0gCLcBGAsYHQ/s320/DJI_0201.JPG"/></a></div>
<i>View to the south-southwest. <a href="https://drive.google.com/file/d/1uQvslAjqZdvw8Z5oC2xDY1BGpUsT6Jqc/view?usp=sharing" target="_blank">LINK to jpg</a></i></p>
<p><div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-i4Cm1U70PUQ/X76H8P6DAsI/AAAAAAAGzjY/Ura8Ym8lvCYl08ZwC9umt-StgzPu9fHcACLcBGAsYHQ/s4056/DJI_0215.JPG" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="3040" data-original-width="4056" src="https://1.bp.blogspot.com/-i4Cm1U70PUQ/X76H8P6DAsI/AAAAAAAGzjY/Ura8Ym8lvCYl08ZwC9umt-StgzPu9fHcACLcBGAsYHQ/s320/DJI_0215.JPG"/></a></div>
<i>View to the south-southeast. <a href="https://drive.google.com/file/d/1Ujz70MvhAsKnaZTUYAYUkZcXUvcMLYB8/view?usp=sharing" target="_blank">LINK to jpg</a></i></p>
<p><div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-xfC6ptlukd0/X76IFF4w61I/AAAAAAAGzjc/_XkC0J1rieA7qcaxRrMOf4yJzvGMeicOACLcBGAsYHQ/s4056/DJI_0173.JPG" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="3040" data-original-width="4056" src="https://1.bp.blogspot.com/-xfC6ptlukd0/X76IFF4w61I/AAAAAAAGzjc/_XkC0J1rieA7qcaxRrMOf4yJzvGMeicOACLcBGAsYHQ/s320/DJI_0173.JPG"/></a></div>
<i>Fissure zone on SW side of higher topography. People for scale. Not sure the purpose of the excavation. <a href="https://drive.google.com/file/d/1uasxjlOY1ibvweeZhRJdYTP9csaVWJR7/view?usp=sharing" target="_blank">LINK to jpg</a></i></p>
<p><div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-S4gcwWq5qFI/X76IOVzi8_I/AAAAAAAGzjk/YyUSV2pb-zoP565vyROuVzMw_vMU6f6GACLcBGAsYHQ/s4056/DJI_0182.JPG" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="3040" data-original-width="4056" src="https://1.bp.blogspot.com/-S4gcwWq5qFI/X76IOVzi8_I/AAAAAAAGzjk/YyUSV2pb-zoP565vyROuVzMw_vMU6f6GACLcBGAsYHQ/s320/DJI_0182.JPG"/></a></div>
<i>Masked and socially distanced field work. <a href="https://drive.google.com/file/d/19rhGBZgBxQY7AUzPWwmIbYqW4Z5R1B6i/view?usp=sharing" target="_blank">LINK to jpg</a></i></p>
<p><div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="Acycv3hAtiE" width="320" height="266" src="https://www.youtube.com/embed/Acycv3hAtiE"></iframe></div><i>Video overflight.</i></p>
<h1>sUAS mapping</h1>
<p>Along with the free flying overviews, I flew in mapping mode (using the PX4D mapper app) over most of the volcano taking 1778 images in mapping mode. I processed those in Agisoft Metashape to produce a colored point cloud, digital elevation model, and orthophoto. The latter two can be the basis of more mapping in ArcMap.</p>
<div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="3Csza_zEJeg" width="320" height="266" src="https://www.youtube.com/embed/3Csza_zEJeg"></iframe></div><i>
Tour of the data and its processing in Agisoft Metashape and ArcMap.</i></p>
<h2>Map downloads</h2>
<div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-xZwQ4HtjHwA/X76Y6DgpzXI/AAAAAAAG0dY/dYt1g6WZ8uI5LjNYBXiA9ZfuZn09DtLQACLcBGAsYHQ/s2048/20201123_WFR_hillshade_overview.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" height="320" data-original-height="2048" data-original-width="1583" src="https://1.bp.blogspot.com/-xZwQ4HtjHwA/X76Y6DgpzXI/AAAAAAAG0dY/dYt1g6WZ8uI5LjNYBXiA9ZfuZn09DtLQACLcBGAsYHQ/s320/20201123_WFR_hillshade_overview.png"/></a></div>
<i>Hillshade overview. 600 dpi pdf download: <a href="https://drive.google.com/file/d/1e86Ern0TqG6y58BhLvIqoqnhR-163-eW/view?usp=sharing">LINK</a>.</i></p>
<div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-qd0QNmT2HXg/X76ZD2hBn0I/AAAAAAAG0eU/55O2TZOE3D4fJB_NLnWZd5qMAdKjLUVKACLcBGAsYHQ/s2048/20201123_WFR_ortho_overview.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" height="320" data-original-height="2048" data-original-width="1583" src="https://1.bp.blogspot.com/-qd0QNmT2HXg/X76ZD2hBn0I/AAAAAAAG0eU/55O2TZOE3D4fJB_NLnWZd5qMAdKjLUVKACLcBGAsYHQ/s320/20201123_WFR_ortho_overview.png"/></a></div>
<i>Ortho image overview. 600 dpi pdf download: <a href="https://drive.google.com/file/d/1RslBJ_YrFRrqy92MYqhx3bcgWKMdBvxz/view?usp=sharing">LINK</a>.</i></p>
<div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-jJIDkDaspHA/X76ZI2uHwdI/AAAAAAAG0e4/hImVVwl4oTQbgqJPPm7F-_dHqqsXbB7ZACLcBGAsYHQ/s2048/20201123_WFR_hillshade_peakarea.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" height="320" data-original-height="2048" data-original-width="1583" src="https://1.bp.blogspot.com/-jJIDkDaspHA/X76ZI2uHwdI/AAAAAAAG0e4/hImVVwl4oTQbgqJPPm7F-_dHqqsXbB7ZACLcBGAsYHQ/s320/20201123_WFR_hillshade_peakarea.png"/></a></div>
<i>Hillshade of peak area. 600 dpi pdf download: <a href="https://drive.google.com/file/d/1NHkHlk7S4CrjVkSF2WIpdeLCBXEjamsQ/view?usp=sharing">LINK</a>.</i></p>
<div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-RnPfjWP-Oqo/X76ZPyCMokI/AAAAAAAG0fo/pdKJZacrB9Ea6krC3c6rDqBMwRa3Oi5tgCLcBGAsYHQ/s2048/20201123_WFR_ortho_peakarea.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" height="320" data-original-height="2048" data-original-width="1583" src="https://1.bp.blogspot.com/-RnPfjWP-Oqo/X76ZPyCMokI/AAAAAAAG0fo/pdKJZacrB9Ea6krC3c6rDqBMwRa3Oi5tgCLcBGAsYHQ/s320/20201123_WFR_ortho_peakarea.png"/></a></div>
<i>Ortho image of peak area. 600 dpi pdf download: <a href="https://drive.google.com/file/d/19D4sWhTyur5_qbzZ6JZYq1xs41qDBBaA/view?usp=sharing">LINK</a>.</i></p>
<h2>Map data downloads</h2>
<ul>
<li>0.1 m/pix DEM and hillshade downloads (tif): <a href="https://drive.google.com/drive/folders/1N8apBLOCWHxvP62nm93kHX-aZ24ZZ0EO?usp=sharing">LINK</a> </li>
<li>0.1 m/pix orthoimage download (tif): <a href="https://drive.google.com/drive/folders/1JuhRF1PDKRdwaLjgth2AssSklxn5-bys?usp=sharing">LINK</a> </li>
</ul>
<h2>Topographic profile</h2>
<p>The video presented above discusses the topographic profile cut from the DEM in ArcMap towards the end. This would be the basis for the geologic cross section, preferably without vertical exaggeration.</p>
<div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-1MwMZuZ22Ko/X76Zww5MvFI/AAAAAAAG0i0/d6iXwpnab4wY0t3H-D4P0azZwaEQ_mkxACLcBGAsYHQ/s987/20201125_WRV_topographic_profile_path.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="784" data-original-width="987" src="https://1.bp.blogspot.com/-1MwMZuZ22Ko/X76Zww5MvFI/AAAAAAAG0i0/d6iXwpnab4wY0t3H-D4P0azZwaEQ_mkxACLcBGAsYHQ/s320/20201125_WRV_topographic_profile_path.png"/></a></div>
<i>Topographic profile location. Bent along the path of our Saturday November 22, 2020 tour. <a href="https://drive.google.com/file/d/1WI_QSjjAhBRQGUwSt9ge2cCcNB35Vhrm/view?usp=sharing" target="_blank">LINK to png</a>.</i></p>
<p>Topographic data text file: <a href="https://drive.google.com/file/d/1_qGKYxjIHPbX_P-J8eMKttzk26jGWIWF/view?usp=sharing">LINK</a> and MATLAB script to plot it: <a href="https://drive.google.com/file/d/1fP99XLEgaJJcGKq6R8sXwZBf0VAMqOrx/view?usp=sharing">LINK</a></p>
<div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-ZZ-K09fAbvg/X76Z2Utq97I/AAAAAAAG0jY/c3yt_YYLH_E9v9kgX7mBiJPhXDVPMMlLwCLcBGAsYHQ/s875/WRtopo.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="656" data-original-width="875" src="https://1.bp.blogspot.com/-ZZ-K09fAbvg/X76Z2Utq97I/AAAAAAAG0jY/c3yt_YYLH_E9v9kgX7mBiJPhXDVPMMlLwCLcBGAsYHQ/s320/WRtopo.png"/></a></div>
<i>No vertical exaggeration. <a href="https://drive.google.com/file/d/1kAdrfOccO6fd4mpJo5etOzIL-0MgYANP/view?usp=sharing" target="_blank">Link to png</a>.</i></p>
<div class="separator" style="clear: both;"><a href="https://1.bp.blogspot.com/-NvTuRD3L9z4/X76Z66IodbI/AAAAAAAG0j4/ktaKFXEJfswTEVX5Qg2AosXUJkBayCv5ACLcBGAsYHQ/s875/WRtopoexagg.png" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="656" data-original-width="875" src="https://1.bp.blogspot.com/-NvTuRD3L9z4/X76Z66IodbI/AAAAAAAG0j4/ktaKFXEJfswTEVX5Qg2AosXUJkBayCv5ACLcBGAsYHQ/s320/WRtopoexagg.png"/></a></div>
<i>Vertical exaggeration. <a href="https://drive.google.com/file/d/1SP0oBQ_tSJOF7Im9mOhWKSEWc3Shlo8y/view?usp=sharing" target="_blank">LINK to png</a></i></p>
<P>2021 ADDENDUM:<br>
For the October 2021 field work, we are trying to use <a href="https://www.strabospot.org/" target="_blank">STRABOSPOT</a> for the digital mapping. I prepared a few items to help:<br>
<ul>
<li>Simple tutorial. The students need to do all but the very last step (uploading after the field) BEFORE we go to the field: <a href="https://drive.google.com/file/d/1Qz4QTlV6ItBuwyXevyGRoqVO_ONmYWD0/view?usp=sharing" target="_blank">PDF</a> </li>
<li>Video tutorial. I recorded all of this on the browser and the tablet with narration.
<div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="xWYh4Tu2UAc" width="320" height="266" src="https://www.youtube.com/embed/xWYh4Tu2UAc"></iframe></div>
</li>
</ul
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-66805090711005978992020-11-06T08:49:00.004-08:002020-11-13T14:45:51.215-08:00Thank you to the American Geophysical Union and colleagues for the Paul G. Silver Award for Scientific Service<p>Thank you for this great honor of the <a href="https://www.agu.org/Honor-and-Recognize/Honors/Section-Awards/Silver-Award" target="_blank">Paul G. Silver Award for Outstanding Scientific Service</a>. Recognition from AGU’s Geodesy, Seismology, and Tectonophysics Sections adds to its heft. I am happy that Paul’s family is represented. I know we have all benefited from <a href="https://carnegiescience.edu/news/seismologist-paul-g-silver-dies-daughter-car-crash" target="_blank">Paul Silver’s leadership and legacy</a>. I was fortunate to meet him on several occasions and appreciated his wit and the spark that drove major science activities on which I was later able to contribute. I am humbled to be in the same list as those who have been awarded before. Congratulations to Doug Toomey--the other recipient this year of the award.</p>
<p>This recognition reflects the efforts of many of my colleagues with whom I have shared numerous projects. I know that many of you are strongly dedicated to serving your families and the communities of your private and scientific lives. I hope that this honor can lift us all as we acknowledge efforts to coordinate activity for our broader good helping others.</p>
<p>It has been satisfying and stimulating to help with major earth science efforts and organizations including <a href="http://geoprisms.org/">GeoPrisms</a>, <a href="https://www.scec.org/">Southern California Earthquake Center</a>, <a href="https://www.earthscope.org/">EarthScope</a>, <a href="https://www.geosociety.org/ages" target="_blank">AGeS - Awards for Geochronology Student Research</a>, and <a href="https://www.opentopography.org/">OpenTopography</a>. I share this recognition with collaborators and friends in those organizations. Colleagues in the National Science Foundation and US Geological Survey have worked mightily to sustain support.</p>
<p>I was inspired to serve by the example of many, including mentors Dallas Rhodes, <a href="https://earth.stanford.edu/people/david-pollard">David Pollard</a>, and <a href="https://www.uni-potsdam.de/en/geo/institute/members/strecker-manfred">Manfred Strecker</a>. Arizona State University’s <a href="https://sese.asu.edu/">School of Earth and Space Exploration</a> Prof. Jim Tyburczy showed me a firm and balanced approach to leadership. My service as associate and deputy to SESE Directors Hodges, Elkins-Tanton, and Wadhwa has given me an opportunity to learn about academic administration and help students, faculty, and staff.</p>
<p>I want to close with a thank you to family including my sister and her husband and their daughters. Our parents--a teacher and a mechanical designer--steadfastly supported me. In their retirement, they served as the <a href="https://losranchosnm.gov/growers-market">Los Ranchos (New Mexico) farmer’s market</a> managers. Their dedicated and steady service made the market an institution. Thank you to my wife Amanda for her love and clear thinking which keeps us going in the right direction.</p>
<p>Here is a video of this speech: <a href="https://drive.google.com/file/d/1snrTHQtrEStYfkEDe3B5azSxxxzmjahc/view?usp=sharing">LINK</a></p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-28261443969210100252020-10-16T11:00:00.004-07:002020-10-16T11:00:58.287-07:00Understanding and interpreting rapidly changing Earth surface processes across a template of a rapidly urbanizing and increasingly connected world<p>Understanding and interpreting rapidly changing Earth surface processes across a template of a rapidly urbanizing and increasingly connected world is a major challenge. Our ability to observe and measure features on the Earth surface is increasing in quality, resolution, and temporal repeat. Thus, we have an opportunity to move understanding beyond the assumption of steadiness. It is clear that many surface phenomena occur rapidly (e.g., wildfires and the subsequent drainage network response, volcanic eruptions, earthquakes, mass movements, etc.). Each is part of a cascade of precursory and subsequent processes.</p>
<p>Revolutions in Earth observing and the connectedness of humanity (e.g., internet of things, social media) provide a major opportunity to characterize surface process events across the world. But they also provide a great data discovery, integration, and analysis challenge. How to bring the disparate observations into a common and quantitative 4D framework so they can be examined, and rates of change measured? For example, satellite imagery such as that available from <a href="https://www.planet.com/" target="_blank">Planet.com</a> provide a daily view of the Earth’s surface at <5m per pixel. This temporal and spatial resolution enables us to observe many phenomena at or near the spatial and temporal scales at which critical processes operate. Discovering these data is relatively straightforward, but their rapid integration with data for context, as well as with ground observations is difficult and time consuming. Integrating the synoptic view from the space-based platform with the typically less intentional but ubiquitous eyewitness views from social media posts or public image sharing platforms can provide essential ground truth, detailed observations of phenomena, and an indication of the human experience of the event.</p>
<p>
For many events, a generic workflow can be imagined:
<ol>
<li>Build on the well curated contextual geospatial data (landcover/land use, topography, imagery, 3D structures) to include (with proper geo- and temporal referencing) near real time Earth observations and compute if necessary derived products of interest (e.g., NDVI for vegetation health).</li>
<li>Discover, locate in time and space, assess for veracity, and examine user contributed or freely posted images and videos from the ground (and maybe from UAS).</li>
<li>Use the high geodetic accuracy of the framework to measure changes using space-based, airborne, and ground-based data. These changes may be spectral or 3D. Use the measurements to contribute to process-based models.</li>
<li>Present predicted conditions (e.g., hazard maps and forecasts) potentially in a updating cycle defined by subsequent additional observations.</li>
<li>Educate both in the short term (explain the event) and long term (enhance science and engineering literacy).</li>
</ol></p>
<p>
Several uses cases are evident:
<ol>
<li>Wildfires: Map forest health using space imaging (NDVI) before, during, and after wildfire seasons. Much commercial space imaging is well configured for measuring vegetation vigor. Exposure of the built environment to the fires (and to subsequent debris flows) would be easy to explore, and hazard maps easily visualized. Including user contributed or freely posted images and videos from the ground (and maybe from UAS) during the fires and after would provide a sense of the detailed processes and phenomena.</li>
<li>Debris flows in mixed wild-agricultural-urban environments: Flooding, especially by heavy sediment-laden flows, are hazardous and their conveyance highly sensitive to the complex 3D near surface environment which many include natural and built structures. Observations of them include larger watershed scale activation and evolution during storm events (space and airborne observations potentially combined with very high resolution 3D data from as built urban models and with on ground experiences from mobile phone picture and video). Flow simulations are available and may be useful for forecasting hazardous conditions, and also maybe updated and calibrated with detailed observations.</li>
<li>Tsunami inundation in complex coastal environments: The 2011 Tohoku Japan earthquake and tsunami showed the very complex and rapid large scale interaction of the rising waters and the coastal Japanese environment. These were observed by some airborne and many haphazard ground-based views. Integrating those observations, and georeferencing imagery to help to measure inundation depths and flow velocities could be done with value for fluid dynamics simulations as well as for tsunamic education for coastal communities.</li>
<li>ETC. </li>
</ol></p>
<p>I wanted to capture this text that I contributed to a recent proposal and stash it here. </p>
<p>This is part of some ideas that I have been working on with capstone students in our capstone class. Here is a link to a presentation: <a href="https://drive.google.com/file/d/1gun5Xv4TrKfpZ7-tN99JxxF9pKlps1yw/view?usp=sharing">LINK</a>.</p>J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-28409216215209324812020-05-15T06:02:00.001-07:002020-05-15T14:50:54.307-07:00Accumulating some links for M6.4 Tonopah area Nevada earthquake May 15, 2020<p>An M6.4 earthquake occurred this morning in SW Nevada 56 km west of Tonopah and 202 km ESE of South Lake Tahoe. It was widely but lightly felt across southern Nevada and the central California from the Sierra Nevada to the coast. It occurred in an area of NW-oriented dextral shearing called the Walker Lane. The size of the event would suggest that there is surface rupture. Fortunately, it is an area of low population density so hopefully no one was hurt and the damage is low. Aftershocks are continuing. </p>
<div class="separator" style="clear: both; text-align: center;"><a href="https://4.bp.blogspot.com/-_atVKNWHTLg/Xr6SdC3RoEI/AAAAAAAGau0/quok4pevHnwJlXZISOs-0xignyIL7m01ACLcBGAsYHQ/s1600/map.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://4.bp.blogspot.com/-_atVKNWHTLg/Xr6SdC3RoEI/AAAAAAAGau0/quok4pevHnwJlXZISOs-0xignyIL7m01ACLcBGAsYHQ/s320/map.png" width="320" height="225" data-original-width="1600" data-original-height="1125" /></a></div>
<p>I am collecting some links in this blog entry:<br>
<ul>
<li><a href="https://earthquake.usgs.gov/earthquakes/eventpage/nn00725272/executive">USGS page on the event</a></li>
<li><a href="http://www.seismo.unr.edu/">Nevada Seismological Laboratory</a></li>
<li><a href="http://seismo.berkeley.edu/">UC Berkeley Seismological Laboratory</a></li>
<li><a href="http://ds.iris.edu/spud/backprojection/18152219">IRIS backprojection</a>--favors the E-W plane</li>
<li><a href="http://earthquake.asu.edu/?id=single&event=nn00725272">Here</a> is the event recorded on our ASU seismometer</li>
<li><a href="http://earthjay.com/?p=9503">Jay Patton report</a>--lots of good content</li>
<li>A few references:</li>
<ul>
<li><a href="https://pubs.geoscienceworld.org/gsa/geosphere/article/15/4/1206/571802/Dextral-normal-and-sinistral-faulting-across-the">Delano, et al., 2019 Geosphere</a> article on the tectonic setting</li>
<li>Active Faulting in the Walker Lane; by Steve Wesnousky (2005)</li>
<li>Pliocene sinistral slip across the Adobe Hills, eastern California–western Nevada: Kinematics of fault slip transfer across the Mina deflection; by Sarah Nagorsen-Rinke et al. (2013)</li>
<li>Recent Wired article on the <a href="https://www.wired.com/story/walker-lane-move-over-san-andreas-fault/">Walker Lane</a></li>
</ul>
</ul>
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-1956120609718750652020-04-22T06:50:00.000-07:002020-05-04T09:09:10.133-07:00Many thanks to Petroleum Experts Limited for 2020 Donation<p>Petroleum Experts Limited has again provided the School of Earth and Space Exploration with licensed software for 2D and 3D kinematic modelling, geomechanical, fracture, and fault response modeling and fault and stress analyses. These licenses are valued at $2,223,600.00 US Dollars and will enable our faculty and students to build and analyze complex 3D fault models to develop understanding of tectonic processes and to anticipate earthquake hazards.</p>
<p> We have acknowledged this donation in our March 2020 SESE Newsletter (<a href="http://view.e.asu.edu/?qs=6acff231103be20abb505cfff86cff88f78423b78128bb57d875e6a15e683c7cb7194d64cc01c0b15ff889508e9834d0f99ad267e4e32a87a5a8c46cb692f20f19967ebe94571204">LINK</a>) as well as express our thanks in our building displays:<br>
<div class="separator" style="clear: both; text-align: center;"><a href="https://2.bp.blogspot.com/-1KY3KcX1vwA/XqBLAJ3sQ3I/AAAAAAAGadI/tQSp-9xdhc4WWBd3NHU9IhAK-gLJSdR8gCLcBGAsYHQ/s1600/MOVE.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://2.bp.blogspot.com/-1KY3KcX1vwA/XqBLAJ3sQ3I/AAAAAAAGadI/tQSp-9xdhc4WWBd3NHU9IhAK-gLJSdR8gCLcBGAsYHQ/s320/MOVE.jpg" width="320" height="190" data-original-width="692" data-original-height="411" /></a></div></p>
<p>We are grateful for this donation. The MOVE suite of software is a powerful environment for 3D interpretation. My students and colleagues are using it to build 3D fault models. We will begin to work on sedimentary architecture in extensional environments in the coming year. In addition, with continued support of the licensed software, we will develop course material for it for our geology majors. </P>
<p><div class="separator" style="clear: both; text-align: center;"><a href="https://1.bp.blogspot.com/-GbBqaH4xFN8/XqBLWLs3uQI/AAAAAAAGadQ/3uoK4QKVRIImLsLHrOxmAwLJYg28gOojgCLcBGAsYHQ/s1600/imageGen.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://1.bp.blogspot.com/-GbBqaH4xFN8/XqBLWLs3uQI/AAAAAAAGadQ/3uoK4QKVRIImLsLHrOxmAwLJYg28gOojgCLcBGAsYHQ/s320/imageGen.png" width="320" height="127" data-original-width="690" data-original-height="273" /></a></div><br>
<i>Example image from Petroleum Experts/MOVE. </i></p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-4404809880200937332020-03-31T17:28:00.000-07:002020-04-06T13:14:50.803-07:00Accumulating links for M6.5 earthquake 72 km west of Challis Idaho 3/31/2020 4:52 pm<p>An earthquake occurred in Idaho today 72 km west of Challis Idaho and about 120 km northeast of Boise Idaho. Based on the magnitude and location, I would think that it looks to be a classic Basin and Range earthquake rupturing along the mountain front south and west of Stanley Idaho (if it occurred along the Sawtooth fault--the closest active fault). But the focal mechanism is more strike-slip; we will have to wait for some updates. </p>
<p>The event was widely felt in the Intermontane west with light to moderate shaking in Boise. It was felt as far as Salt Lake City, Bozeman, and Spokane. The strongest ground motions appear to have been in the relatively low population Challis National Forest. <a href="https://earthquake.usgs.gov/earthquakes/eventpage/us70008jr5/oaf/commentary">Numerous aftershocks are expected</a>.</p>
<p><div class="separator" style="clear: both; text-align: center;"><a href="https://3.bp.blogspot.com/-ebJr-xSdwL8/XoPmw3nz1rI/AAAAAAAGZ6Y/EYsH_vNP_xArMExB7dj-k75dvEmQ3MyEwCLcBGAsYHQ/s1600/IDeq.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://3.bp.blogspot.com/-ebJr-xSdwL8/XoPmw3nz1rI/AAAAAAAGZ6Y/EYsH_vNP_xArMExB7dj-k75dvEmQ3MyEwCLcBGAsYHQ/s320/IDeq.png" width="320" height="278" data-original-width="1432" data-original-height="1242" /></a></div><br>
Location of the epicenter in the Sawtooth Mountains. The yellow line to the south is the Sawtooth fault. Note the focal mechanism indicating strike-slip sense of motion</p>
<p>
Links:<br>
<ul>
<li><a href="https://earthquake.usgs.gov/earthquakes/eventpage/us70008jr5/executive">Main USGS Page on the event</a></li>
<li>Idaho Geological survey <a href="https://www.idahogeology.org/stanley-earthquake">page on the event</a></li>
<li><a href="https://twitter.com/IDGeoSurvey/status/1245183653874786309">Fault map</a> of the area from Idaho Geological Survey</li>
<li><a href="http://earthquake.asu.edu/EQplots/us70008jr5.pdf">Seismogram </a>recorded at ASU (thanks to John West, Ed Garnero, and Wendy Lin)</li>
<li><a href="https://twitter.com/IRIS_EPO/status/1245314094938443776">Ground Motion Visualization</a> from IRIS</li>
<li><a href="https://temblor.net/earthquake-insights/magnitude-6-5-quake-strikes-idaho-10775/">Writeup</a> on the event from Temblor.net by <a href="http://tieganhobbs.com/">Tiegan Hobbs</a></li>
<li><a href="https://www.unavco.org/highlights/2020/challis.html">UNAVCO response page</a></li>
<li><a href="https://twitter.com/SotisValkan/status/1245287785411592192">Mapping </a>of the area by Sotiris Valkaniotis</li>
<li><a href="https://twitter.com/CPPGeophysics/status/1245429835192770560">Seismicity map</a> by Jascha Polet</li>
<li><a href="https://twitter.com/cataclasite/status/1245413937719291905">Geologic map</a> of the area (H/T Mike Bunds)</li>
<li><a href="https://twitter.com/TTremblingEarth/status/1245375451725312007">Geomorphic pondering</a> by Austin Elliott</li>
<li><a href="https://twitter.com/janinekrippner/status/1240673880798310407">Commentary </a>on why this would not be likely to have an effect on Yellowstone volcanic system (note that Mike Poland is an ASU Alum)--comments are for the Utah earthquake from a few weeks ago, but still generally relevant.</li>
<li><a href="https://seismo.berkeley.edu/blog/2015/01/05/rock-and-roll-in-the-gem-state.html">Tectonic setting</a> (from UCB Seismo Lab)</li>
</ul>
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-92192988026800456912020-03-30T07:35:00.002-07:002021-05-17T12:00:33.676-07:00Virtual field geology exercises for GLG451 Field Geology I Spring 2020<p>Even before the COVID-19 crisis changed everything, I was working this semester to build some virtual options for my Field Geology I (GLG451) course. Two students are physically unable to do the field work, and then another had a crisis and missed two weekend field trips. The course has three weekend field trips and then a mini camp over spring break.</p>
<p><div class="separator" style="clear: both; text-align: center;"><a href="https://3.bp.blogspot.com/-IVOgP2uKZwc/XoIDb4Sqe4I/AAAAAAAGZ3U/genFlK8U0mMy0ZnJWDy5dnJLCUDFHuKOwCLcBGAsYHQ/s1600/20200117_glg451_01intro.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://3.bp.blogspot.com/-IVOgP2uKZwc/XoIDb4Sqe4I/AAAAAAAGZ3U/genFlK8U0mMy0ZnJWDy5dnJLCUDFHuKOwCLcBGAsYHQ/s320/20200117_glg451_01intro.png" width="320" height="240" data-original-width="960" data-original-height="720" /></a></div><br>
<i>Locations of the field trips</i>.</p>
<p>I decided to try to build some digital versions of the field trips using very high resolution digital elevation models and orthophotos from our SUAS systems (thanks to Tyler Scott for doing the flying and the SfM work). I wanted these to be as similar as possible to what the regular students experience so I give some initial information on the maps as well as numerous pictures from the ground and videos from the sUAS. For most of the exercises in the case of my class, I also am providing rock samples to the students of each of the mapping units. </p>
<p>All of the information for each of the assignments is in a long pdf which has the text assignment, links to data and images, etc. and then some explanation. It also has a topographic profile for a cross section, etc.<br>
I am very happy to share with anyone who might find these useful. Here are the modules and the current status:<br>
<table>
<tr><th>Module</th><th>Status</th><th>Link</th><tr>
<tr><td>Dreamy Draw, Phoenix Mountains, AZ</td><td>Done</td><td><a href="https://drive.google.com/file/d/1naOCxIkd6226mHfQ_caSEGHPbhFLAUYi/view?usp=sharing">LINK</a></td></tr>
<tr><td>Goldfields, Superstition Mountains, AZ</td><td>Done</td><td><a href="https://drive.google.com/file/d/1FZYkgd235aVSMqPrb20pRM0GPA_3MOQS/view?usp=sharing">LINK</a></td></tr>
<tr><td>Salt River, Bush Highway, AZ</td><td>Done</td><td><a href="https://drive.google.com/file/d/1InBPYLJZJX4oBCm7UY0B6JLGrB4l_5kA/view?usp=sharing">LINK</a></td></tr>
<tr><td>Arnett Creek, AZ</td><td>Done</td><td><a href="https://drive.google.com/file/d/1zIajU74HdzL6bR-7XoUm55uEwoKegH4V/view?usp=sharing">LINK</a></td></tr>
</table>
<p>Example video for the Goldfields in which we fly along the path of the introductory tour:<br>
<iframe width="560" height="315" src="https://www.youtube.com/embed/WfaPu4FFZxQ" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
</p>
<p>Here is an example of one of the explanatory tutorial videos for ArcGIS:<br>
<iframe width="560" height="315" src="https://www.youtube.com/embed/2DWOqaCdKVg" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
</P>
<p>Here is geology tour for the Salt River mapping project:<br><div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="QMyjWNciprA" width="320" height="266" src="https://www.youtube.com/embed/QMyjWNciprA"></iframe></div>
</P>
<p>Here is longer geology tour for the Arnett Creek Spring Break mapping project:<br>
<div class="separator" style="clear: both; text-align: center;"><iframe class="BLOG_video_class" allowfullscreen="" youtube-src-id="XfbfCadSJ2Y" width="320" height="266" src="https://www.youtube.com/embed/XfbfCadSJ2Y"></iframe></div>
</P>J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-2097670448938379572020-03-18T10:05:00.001-07:002020-03-19T05:39:48.168-07:00Accumulating links for today's southern Salt Lake Utah area earthquake (M5.65 earthquake 4km NNE of Magna, Utah: 03/18/2020 6:09:31 AM AZ time)<p>A M5.7 earthquake occurred this morning and it was widely felt along the northern Wasatch Front. Numerous aftershocks have occurred and will continue. Its characteristics are consistent with the crustal extension occurring in the region (Basin and Range).</P>
<p>I am accumulating some links here:<br>
<ul>
<li><a href="https://earthquake.usgs.gov/earthquakes/eventpage/uu60363602/executive">Main USGS page on the event</a></li>
<li><a href="https://quake.utah.edu/press/magnitude-5-7-near-magna-ut">University of Utah Seismo lab post</a> Site looks like it might be pretty busy here is their main page <a href="https://quake.utah.edu/">https://quake.utah.edu/</a><br> <a href="https://www.youtube.com/watch?v=TQgDkOMudGk">UofU Seismo press conference</a></li>
<li><a href="https://twitter.com/AZGeology/status/1240310790155984896">Seismograms from AZ Broadband network</a> (managed by <a href="https://sese.asu.edu/">SESE</a> alum Jeri Young-BenHorin, PhD 2004)</li>
<li><a href="http://earthquake.asu.edu/EQplots/uu60363602.pdf">Seismogram plots from <a href="https://sese.asu.edu/">SESE</a> seismologists John West and Ed Garnero</a><br>
Interpretation from Garnero: "for this earthquake we get to see some natural polarization of the surface waves, since the energy comes to ASU from due North. The Love wave is shear wave that vibrates purely perpendicular to the direction the energy comes from (thus we see something on the East-West component of motion that is not really present on the North-South or Up-Down). It is named after the mathematician A.E. Love who discovered them. In contrast, the Rayleigh wave (named after Lord Rayleigh) has P-wave and shear wave energy (that is perpendicular to the Love wave-making shear wave) combined, and it is nearly purely on the vertical and N-S components. It arrives after the love wave. We don't always see such a clear separately of the surface waves."</li>
<li><a href="https://twitter.com/IRIS_EPO/status/1240386136410906625">Watch the seismic waves roll across North America on the USArray</a></li>
<li><a href="https://twitter.com/chrisduross/status/1240382358563495939">Nice graphic</a> (updated) from Chris DuRoss on the event position relative to the projection of the Wasatch Fault</li>
<li>Background from Utah Geological Survey:
<a href="https://geology.utah.gov/map-pub/survey-notes/wasatch-fault-above/">https://geology.utah.gov/map-pub/survey-notes/wasatch-fault-above/</a> (written by <a href="https://sese.asu.edu/">SESE</a> alum Emily Kleber MS 2015; now works for Utah DNR and is out surveying the damage today)<br>
<a href="https://utahdnr.maps.arcgis.com/apps/Cascade/index.html?appid=a40122474bcf4f13a2c17a82039403df">Nice overview of the Wasatch Fault history</a> </li>
<li>Teaching/explanatory items from IRIS (note that <a href="https://sese.asu.edu/">SESE</a> alum Wendy Bohon PhD 2014 is one of their communications leads):<br>
<a href="https://www.iris.edu/hq/inclass/animation/basin__range_gps_measures_extension">Animation of Basin and Range extension measured by GPS</a><br>
<a href="https://www.iris.edu/hq/inclass/animation/fault_normal">Normal fault animation</a></li>
</ul>
</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-28851799256369722592020-01-12T10:50:00.001-08:002020-01-12T10:50:33.697-08:00Haiti earthquake 10 years commemoration<p>January 12, 2010 was the devastating Haiti earthquake. Many are posting memories and thoughts about the event. Many others have higher quality scientific, engineering, and social science materials. I did not work on it directly but I developed a few slides for various lectures which referred to the event.</p>
<p>I recall a moving lecture on the event by Eduardo Fierro who had been there for post earthquake response. The video may still be accessible (I am struggling to see it here, but the PDF is available): <a href="https://apps.peer.berkeley.edu/publications/haiti_2010/related_events_haiti.html">PEER website</a>. He made a strong point about what really caused the disaster: "The tragedy of this thing, you know, was that three days after the earthquake the city was littered with bodies and by God, we… this was not an earthquake disaster. This was a disaster caused by the construction industry in Haiti. The construction industry that did not know how to use codes, they did not have any codes, and the people that built these things, the building in very bad shape. These were the people that caused this tragedy and the loss of human life. In the past I have told people when I give talks: We have to design things and construct things and assume that our children, our grandchildren and our mother is going to be in this building when the earthquake hits. So we check all our numbers and do a proper design ." 01/26/2010, by Eduardo Fierro</p>
<p>I also was surprised by some of the news discussions about the relative magnitudes of the 2010 Haiti and Chilean earthquakes. The latter occured about 6 weeks after the Haiti event and was much larger. Some news reports talked about how the M8.8 Chile earthquake was 500x larger while others said 64x. Which was it? I set this up as a little exercise for my class<br>
<div class="separator" style="clear: both; text-align: center;"><a href="https://3.bp.blogspot.com/-GD7bD6mG4_A/Xhtp9CXLypI/AAAAAAAGVWE/h_VojOIdLWQ279gBzUa33Gq3Ad_YN2bQQCLcBGAsYHQ/s1600/Slide7.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://3.bp.blogspot.com/-GD7bD6mG4_A/Xhtp9CXLypI/AAAAAAAGVWE/h_VojOIdLWQ279gBzUa33Gq3Ad_YN2bQQCLcBGAsYHQ/s320/Slide7.PNG" width="320" height="240" data-original-width="960" data-original-height="720" /></a></div>
</p>
<p>Here are all of the slides: <a href="https://drive.google.com/file/d/1dZ_NQV3mAaAwRIEn-UuIamSjLnv2U6mS/view?usp=sharing">PDF </a> <a href="https://drive.google.com/file/d/1zWIEl0-wfhFZEi9ok1dnFAyg8xlo74Y2/view?usp=sharing">PPT</a></p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-59040787174516320392020-01-04T16:20:00.001-08:002020-01-04T16:25:25.751-08:00Propelling ASU's School of Earth and Space Exploration<p>In May 2019, my colleague Prof. <a href="https://isearch.asu.edu/profile/957644">Meenakshi Wadhwa</a> was <a href="https://asunow.asu.edu/20190628-discoveries-meenakshi-wadhwa-ready-lead-earth-and-space-exploration-asu">appointed</a> the Director of ASU's <a href="https://sese.asu.edu/">School of Earth and Space Exploration</a>. This is a really good thing for SESE given Mini's many strengths and achievements and SESE's great potential in Earth and Space Sciences. I have continued my role as Deputy Director for SESE (I had done the same for our former Director <a href="https://sese.asu.edu/node/1343">Lindy Elkins-Tanton</a>). It has been an honor to work for both Lindy and Mini. They are inspiring and effective leaders.</p>
<p>I too applied to be the Director and am very happy that Mini is the director. I put some energy into my application materials thinking about SESE and my own leadership experience and vision, so I have decided to post them here. If nothing else, it will help me find them quicker as I tend to refer to them occasionally.</P>
<p>
<ul>
<li>Curriculum Vitae as of February 8, 2019: <a href="https://drive.google.com/file/d/1nYwXgR3fRWbx2iDyRT-VgRBDR1Q3hm5_/view?usp=sharing">LINK</a></li>
<li><a href="https://drive.google.com/file/d/1Jvj7nfS1HzRR3Fk6MD-TQEDY69f4qCez/view?usp=sharing">A Vision for the School of Earth and Space Exploration</a></li>
<li>Presentation <a href="https://drive.google.com/file/d/1OwYTFYkon07hFRnASQB5kmmbtx5zfRd9/view?usp=sharing">PPT</a> <a href="https://drive.google.com/file/d/1oFTK_0f2RKXX8y2Hraqjj0MRFSUIHWrn/view?usp=sharing">PDF</a> -- this was not so great in that I got sick on the second day of the interview and so it was delivered in a hoarse whisper! It was a sign probably that I could not hack it (the job that is; it was a stressful time).</li>
</ul>
</p>
<p>
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</p>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-49653432191493732132019-12-16T17:07:00.000-08:002019-12-16T17:08:40.460-08:00Call for research papers: Unveiling Active Faults: Multiscale Perspectives and Alternative Approaches Addressing the Seismic Hazard Challenge<p>Along with <a href="https://loop.frontiersin.org/people/788263/overview">Federica Ferrarini</a>, <a href="https://loop.frontiersin.org/people/843934/overview">Nathan Toké</a>, and <a href="https://loop.frontiersin.org/people/457624/overview">Michele M. C. Carafa</a>, we are looking forward to submissions to this special "issue" from the <a href="https://www.frontiersin.org/">Frontiers journal</a>: <a href="https://www.frontiersin.org/research-topics/12168/unveiling-active-faults-multiscale-perspectives-and-alternative-approaches-addressing-the-seismic-ha">Unveiling Active Faults: Multiscale Perspectives and Alternative Approaches Addressing the Seismic Hazard Challenge</a>.</p>
<p>Federica made a nice flyer to share: <a href="https://drive.google.com/file/d/1E0EWbY4-tqF4ilUOoQfo5xPO9gKQ0UT9/view?usp=sharing">LINK</a></p>
<p><div class="separator" style="clear: both; text-align: center;"><a href="https://1.bp.blogspot.com/-BdcdXO5qrCI/XfgnVoqpVyI/AAAAAAAGVLY/Xu5rNbQxDOMG8qKmgQD0LG-JZwSjvNOjwCLcBGAsYHQ/s1600/Cover_image_FACT_research_topic.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://1.bp.blogspot.com/-BdcdXO5qrCI/XfgnVoqpVyI/AAAAAAAGVLY/Xu5rNbQxDOMG8qKmgQD0LG-JZwSjvNOjwCLcBGAsYHQ/s320/Cover_image_FACT_research_topic.JPG" width="320" height="289" data-original-width="1600" data-original-height="1445" /></a></div><br>
<i>Central Apennine settled landscape with active normal fault (photograph by <a href="https://loop.frontiersin.org/people/788263/overview">Federica Ferrarini</a>)</i>.</p>
<p>Despite decades of progress toward mitigating seismic hazard, characterizing the seismic potential of an area remains a complex process.
Particularly challenging are seismically active regions characterized by low slip rate faults which can give rise to weak geomorphic expressions when combined with high erosion or sedimentation rates.
Similar compounding issues may also manifest in densely populated areas where anthropogenic modifications, or vegetation cover further challenge assessment of fault activity or where structural complications may contribute to multiple interpretations.
Noticeable advances in remote sensing technology geodetic measurements and dating Late Quaternary landforms and sediments have moved our understanding forward.
</p>
<p><b>This Frontiers Research Topic welcomes contributions that present examples and approaches which strive to improve our understanding of active faulting processes over diverse geological settings and at broad spatial scales of investigation.</b> We encourage the submission of research papers from a wide range of geoscience disciplines (field geology, structural geology, tectonic geomorphology, paleoseismology, seismology, remote sensing, numerical modeling) and from the scale of a field site to regional scale analyses. We welcome contributions with the main goal to bridge the gap between our observations, fundamental understanding of faulting processes, and effective seismic hazard assessment.</p>
<p>Please think about a contribution! Submit an abstract by January 29, 2020 (not required). The manuscripts are due May 29, 2020.</P>
J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0tag:blogger.com,1999:blog-6321857130143408896.post-49230156573384110182019-10-05T11:06:00.003-07:002020-12-29T11:13:21.357-08:00(Finally) Getting going with python (and a bit of history)<p>I certainly recognize the power of scientific programming. Programming spreadsheets is obvious and there is nothing to be ashamed of there (see <a href="http://arrowsmith410-598.asu.edu/GLG410--Lectures.html">weeks 2-6</a> in my <a href="http://arrowsmith410-598.asu.edu/index.html">Computers in Earth and Space Exploration</a> course). I started off in grad school with <a href="https://www.wolfram.com/mathematica/">Mathemematica</a> and appreciated the notebook style of computations and integrated graphics and text. I also taught myself enough <a href="https://web.stanford.edu/class/me200c/tutorial_77/">fortran </a>to get the main calculations for my <a href="https://searchworks.stanford.edu/view/3053626">dissertation </a>completed.</p>
<div class="separator" style="clear: both; text-align: center;"><a href="https://1.bp.blogspot.com/-55huVR5pF-A/XZjZ4dxVfNI/AAAAAAAGRtU/Iu-JqAzOHI8x5-Orl4_X324xpKsRncLsACLcBGAsYHQ/s1600/wc.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://1.bp.blogspot.com/-55huVR5pF-A/XZjZ4dxVfNI/AAAAAAAGRtU/Iu-JqAzOHI8x5-Orl4_X324xpKsRncLsACLcBGAsYHQ/s320/wc.png" width="320" height="247" data-original-width="1107" data-original-height="856" /></a></div><br>
<i>Modeling profile development with simple diffusion (Arrowsmith, et al., 1998) using fortran code and Mathematica for the basic graphics.</i>
<p>I took some programming courses (Pascal) back in grad school. I was not very good at it. Once the professor even said "that is the stupidest way I have ever seen for doing that" in office hours. I was not too offended; I barely understood what I was doing. Nevertheless, I got the big picture and have stumbled along ever since.</p>
<p><a href="https://earth.stanford.edu/people/george-hilley">Professor George Hilley</a> taught me many things. One thing he was able to do after a fair amount of cajoling was to get me to start in <a href="https://www.mathworks.com/">MATLAB</a>. The more data-oriented and matrix handling of MATLAB ended being something I could use effectively. We also worked with <a href="http://activetectonics.blogspot.com/2019/07/remembering-donal-m-ragan.html">Don Ragan</a> a lot on MATLAB and <a href="https://www.latex-project.org/">Latex</a>. While I am no expert, I have taught the basics to students over the years see <a href="http://arrowsmith410-598.asu.edu/GLG410--Lectures.html">weeks 6-9</a> in my <a href="http://arrowsmith410-598.asu.edu/index.html">Computers in Earth and Space Exploration</a> course). I cannot say that I have had any really great programming projects, but the various analysis and plotting needs have been satisfied. For what it is worth, I even set up a <a href="https://github.com/jrarrowsmith">GitHub </a>page to hold a few things. <a href="https://ces.kaust.edu.sa/Pages/Olaf-Zielke.aspx">Dr. Olaf Zielke</a> is a serious MATLAB programmer and wrote some impressive tools with GUIS for his PhD and related work. <a href="https://topotoolbox.wordpress.com/">TopoToolbox </a>is another set of MATLAB-based tools which I had the <a href="https://opentopography.org/workshops/advancing_understanding_geomorphology_topographic_analysis">opportunity to learn and appreciate</a> their transformative power for a lot of geomorphic analyses.</p>
<p>I have been watching the progressive adoption of <a href="https://en.wikipedia.org/wiki/Python_(programming_language)">Python</a> and related tools in my little scientific bubble over the last 5 or so years. I have not had the time to do much as far as learning until recently, however. While my MATLAB expertise won't go away, I have appreciated the fact that it is hard to share and teach with students and colleagues who don't have access to the rather expensive licenses for MATLAB. On the other hand, Python and related tools are open and apparently so adaptable and customizeable. </p>
<P>Recently, I finally had an excuse and the time to get my feet wet with Python. <a href="https://connect.unavco.org/display/per508132">Chris Crosby</a> and I (<a href="https://opentopography.org/">OpenTopography</a>) helped out with a short course <a href="https://github.com/UP-RS-ESP/PointCloudWorkshop-Oct2019">From point clouds and full-waveform data to DEM analysis (Sep-30 to Oct-4 2019)</a> led by <a href="http://www.geo.uni-potsdam.de/member-details/show/524.html">Professor Bodo Bookhagen</a> and his team. </P>
<div class="separator" style="clear: both; text-align: center;"><a href="https://1.bp.blogspot.com/-Y2YQ4_9pv3k/XZjaVH6sd3I/AAAAAAAGRtg/YEnhpMkSzIAqgUZeG7jOjBszfQPpCLfzQCLcBGAsYHQ/s1600/sca_fan.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://1.bp.blogspot.com/-Y2YQ4_9pv3k/XZjaVH6sd3I/AAAAAAAGRtg/YEnhpMkSzIAqgUZeG7jOjBszfQPpCLfzQCLcBGAsYHQ/s320/sca_fan.png" width="320" height="199" data-original-width="1600" data-original-height="996" /></a></div><br>
<i>Specific catchment area computed with the tools from Rheiwalt, et al., 2019. The basic processing was in Python with some c code and then visualized using <a href="http://c42f.github.io/displaz/">Displaz</a>.</i>
<br>
<div class="separator" style="clear: both; text-align: center;"><a href="https://1.bp.blogspot.com/-rnLcMYBsaJE/XZjaVNxs4pI/AAAAAAAGRtc/BQnZn0XnrVQRVYPdBIsOoeBxjlaBUH1SQCLcBGAsYHQ/s1600/fwf_displaz_example.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://1.bp.blogspot.com/-rnLcMYBsaJE/XZjaVNxs4pI/AAAAAAAGRtc/BQnZn0XnrVQRVYPdBIsOoeBxjlaBUH1SQCLcBGAsYHQ/s320/fwf_displaz_example.png" width="320" height="180" data-original-width="1600" data-original-height="900" /></a></div><br>
<i>Here is some basic <a href="https://github.com/UP-RS-ESP/PointCloudWorkshop-Oct2019/tree/master/examples">full waveform lidar processing from Bookhagen and Rheinwalt</a> again basic procesing in Python and then visualized using <a href="http://c42f.github.io/displaz/">Displaz</a>.</i>
<p>I still don't understand all that I am doing, but I got the basic set up and can sort of understand packages and environments. Javier Colunga helped me by getting <a href="https://www.anaconda.com/">Ananconda </a>installed. <a href="https://www.spyder-ide.org/">Spyder </a>is the development environment I had been looking for. There is so much that is possible; it is hard to even know where to start.</p>
<p>For my first project, I thought it would be nice to play around with a lidar point cloud (using the <a href="https://activetectonics.blogspot.com/2013/09/exploring-topographic-response-to.html">Dragon's Back</a> of course): grid it using <a href="https://pdal.io/python.html">pdal</a> and then make a hillshade using <a href="https://gdal.org/">gdal</a>. Download the <a href="http://opentopo.sdsc.edu/lidarOutput?jobId=pc1570299476276">data </a>from OpenTopography.</p>
<p>The steps are: <br>
<ol>
<li>Launch an Ananconda terminal. </li>
<li>Add these conda channels for package install:<br>
<code>conda config --prepend channels conda-forge/label/dev<br>
conda config --prepend channels conda-forge</code></li>
<li> Then define an environment and add the packages using conda: <code>conda create -y -n PC_py3 python=3.6 pip scipy pandas numpy matplotlib scikit-image gdal pdal xarray packaging ipython multiprocess h5py lastools pykdtree spyder gmt=5* </code> (this comes from <a href="https://github.com/UP-RS-ESP/PointCloudWorkshop-Oct2019/blob/master/PDF/PC_Required_Software_Workshop.pdf">the workshop</a>).</li>
</ol>
<p>My first problem was that I could not run pdal from inside a python script. There is something I don't understand there (even though it is installed, etc.). I see that it is possible to call python from inside the pdal json files... But, I can run it from the command line:<br>
<code>> pdal pipeline db.json</code><br>
where the <code>db.json</code> has the parameters for the simple neighborhood gridding run:<br>
<pre><code>
{
"pipeline":[
"smallpiece.laz",
{
"resolution": 1,
"radius": 0.707,
"gdaldriver": "GTiff",
"gdalopts": "COMPRESS=DEFLATE, ZLEVEL=7, GDAL_NUM_THREADS=ALL CPUS",
"data_type": "float",
"output_type": "idw",
"filename":"small_idw_1m.tif"
}
]
}
</code></pre>
I was able to make a little dem (the tif file). But then, I ran the gdal from the command line only: <br>
<code>>gdaldem hillshade small_idw_1m.tif small_idw_1m_shd.tif</code></p>
</p>
<p>Finally, I could run a little python script to draw the hillshaded geotiff (this I could run from Spyder):<br>
<pre></ode>
#!/usr/bin/env python
import gdal
import matplotlib.pyplot as plt
ds = gdal.Open('small_idw_1m_shd.tif').ReadAsArray()
plt.close('all')
plt.imshow(ds, cmap='gray')
f.savefig('smallDB.png', dpi=300)
plt.close('all')
</code></pre><br>
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<i>Small piece of the Dragon's Back lidar data (B4 project) gridded with pdal, hillshaded with gdal, and drawn with matplotlib</i>
</p>
<p>So, I guess that is a bit of a success, there is a lot more to do and learn!</p>
<p>I keep finding references to help learn:<br>
<ul>
<li><a href="https://github.com/jakevdp/PythonDataScienceHandbook">Python Data Science Handbook</a></li>
<li><a href="https://drive.google.com/file/d/1EmEf4CWQqvAGpNDUK2e8r73L_a6f9PVd/view?usp=sharing" target="_blank">Butler et al. 2020 paper on PDAL in Computers in Geosciences</a></li>
</ul>J Ramón Arrowsmithhttp://www.blogger.com/profile/16969196632800326289noreply@blogger.com0