Monday, November 21, 2011

Repeat photography shows the amazing damage and rebuilding after the March 2011 Japan earthquake and tsunami

This came floating along in the news feed in Facebook from Sue Owen, but seems so impressive it is worth a blog entry to capture it for a while:


This combo image, the initial destruction and progress of cleanup after the March 11, 2011 earthquake and tsunami is seen in Kesennuma, Miyagi prefecture, northern Japan. The top photo, taken March 13, shows a street covered by debris burnt by a fire. The middle photo, taken June 3, 2011 shows a partial clean-up of the same street, while the bottom photo taken Sept. 1, 2011 shows the area after the debris was removed. AP / Kyodo News

Saturday, November 12, 2011

Updated pages for Kite and Balloon Aerial Photography

Thanks to the hard work of Tsurue Sato, we have a newly updated set of pages for Kite and Balloon Aerial Photography.

The new pages are connected from our Activetectonics research page: Low Altitude Aerial Photography.

I have an old blog posting on this topic as well: Balloon Photography Update. Note that the videos there and on the new pages are some of the most popular of my youtube videos because they were embedded on the Arizona Balloon Company homepage...

Here is a recent photo from CAMP SESE:

Sunday, August 28, 2011

USGS real time stream gages and Hurricane Irene effects of streamflow

The US Geological Survey real time stream gages are nicely reflecting the passage of high precipitation associated with Hurricane/Tropical storm/depression Irene: The dots on the map show a general view of the state of flow and many black ones indicating high flow are in the northeast. (USGS Hurricane Irene resources).

If you click on a state (e.g., Pennsylvania) you can zoom in and then click on a particular gage to see the current flow state and its change with time (hydrograph) and build your own graphs, etc.

Here is the page for the Conestoga River at Lancaster, PA which at least right now (Sunday afternoon August 28, 2011) is on the steep rising limb of the hydrograph:

Location is here at this link

This is a critical USGS function that is under threat of severe reduction due to budget cuts.

I noticed that sometimes you have to reload a few times or just wait for the main map to appear. I don't know if they are getting heavy loads due to public interest or what is going on.

Hat tip to Michelle Cooke for this idea.

Tuesday, August 23, 2011

M5.9 earthquake in Virginia, August 23, 2011

A moderate earthquake occurred today in Virginia (about 66 km NW of Richmond Virginia). It is listed as M5.9 by the USGS and was widely felt in the northeast and mid Atlantic region.

Here is the main USGS site on the event: It looks like it was a NNE-trending reverse faulting mechanism (makes some sense with the geologic fabric and the compression directions in the eastern US).

UNAVCO Community Event Response to the 23 August 2011, Mw=5.8 Virginia Earthquake

Watch the event propagate through the USArray: USArray Ground Motion Visualization

Here is a nice NY Times article with information about the damage, a comparison of the felt effects from this event a similar-sized 2004 California earthquake (Parkfield), and a map of historic events in the eastern US (last big event was 5.4 in New Hampshire in 1940).

Watch the Did You Feel It page to see people report their sensation of the event and where.

Here is a short comment about the difference in attenuation between the east and west of North America.

It looks like it occurred within the Central Virginia Seismic zone which is an area that has produced small and moderate events in the past and is noted as a zone of somewhat increased earthquake hazard by the USGS. Note that there was an M4.5 in this area in 2003 (December 9). It was also widely felt.

Note that this was a tie for the largest earthquake recorded in Virginia: Giles County, Virginia 1897 05 31 18:58 UTC Magnitude 5.9

Here it is relative to historic seismicity. Click on link to see it broader with explanation (from USGS OFR 2006-1017):

from but is derived from the USGS Open File report 2006-1017 below).

Here is a nice map and commentary from Virginia Tech on the Central Virginia Seismic zone.

Social media will be an important channel for people to communicate about this event:
Here are a few youtube links:
Earthquake Virginia Auto Repair Shop Collapses G&C
DC / Virginia Earthquake Aftermath

Wikipedia site is accumulating contributions:

Here it is recorded at Arizona State University (thanks John West):

Here are a few other links I just came up with:
Major earthquakes in Virginia (from Virginia Division of Geology and Mineral Resources)
Earthquakes in Virginia and Vicinity 1774 - 2004 (USGS Open File Report 2006–1017) (big file and takes a while to download)
Virginia Earthquake Information from the USGS

IRIS Event plot suite

Tectonic Setting of the August 2011 Virginia Earthquake (Stein, et al.)

Latest update: 19:05 Arizona time August 29, 2011

Monday, August 8, 2011

Wallace Creek: New radiocarbon results and slip rate estimates of the San Andreas Fault in the Carrizo Plain

Our team along with Sinan Akciz and Lisa Grant-Ludwig from UC Irvine just finished a SCEC-supported project to re excavate a few of the trenches from the now famous work published as Sieh and Jahns, 1984 at Wallace Creek. While the slip rate of the San Andreas Fault has been well established at about 36 mm/yr from that work, it is only constrained by a few radiocarbon dates. With our experience working in the area and the enhanced capabilities of the W. M. Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory  at UC Irvine, we proposed that it was time to revisit the ages of the main offset channel at Wallace Creek.

Aerial view of open excavations (photograph by Wendy Bohon, ASU)

View Larger Map

The effort was highlighted in a local newspaper: .

Here is our SCEC abstract that was just submitted (the title of this blog entry is the same):

Revisiting Wallace Creek: New radiocarbon results and slip rate estimates of the San Andreas Fault in the Carrizo Plain

S.O. Akciz, D.E. Haddad, W. Bohon, L. Delgadomendes, G. Marliyani, B. Salisbury, T. Sato, L. Grant Ludwig, J R. Arrowsmith

Sieh and Jahns (1984) determined the slip rate of the San Andreas fault (SAF) at Wallace Creek in the Carrizo Plain, and thereby provided an anchor for nearly all data-driven models of the southern San Andreas fault behavior. Their landmark study has been referenced hundreds of times and is a critical constraint in many related studies and in hazard estimates for the south-central SAF. Slip rate estimates at Wallace Creek (33.9±2.9 mm/yr) and at Van Matre Ranch site
(29.3-35.6 mm/yr; Noriega et al., 2006) agree well within measurement uncertainty, and with the 30–37 mm/yr velocity gradient across the SAF from decadal timescale geodetic measurements (Schmalzle, et al., 2006). Surprisingly, only a few detrital charcoal samples (9 samples at VMR, 8 samples at Wallace Creek) have been used to provide the absolute geochronological constraints. At a third site, Phelan Creeks, located ~ 2.5 km SE of Wallace Creek, 23 trenches were opened and over 400 charcoal samples were collected (Sims et al., unpublished data) to provide additional slip rate constraints, but the detailed study was never published.

New paleoseismologic investigations at the Bidart Fan site, ~5 km SE of Wallace Creek, indicate that southern SAF in the Carrizo Plain has apparently ruptured, on average, every 88 years (45-144 yr for individual intervals) between ~A.D. 1350 and 1857 (Akciz et al., 2010). B4 LiDAR (light detection and ranging) data analysis by Zielke et al. (2010) also found that only ~5.5 m of slip occurred along the SAF in the Carrizo Plain in 1857 and at least since ~A.D. 1400, and none of the earthquakes generated displacements larger than 5 meters (Grant Ludwig et al., 2010).

Slip per event and earthquake timing constraints can be tested against slip rate information to assess the steadiness of slip. Therefore, these new data and the geochronological limitations of the published slip-rate studies emphasize the need to improve, if not confirm, the existing slip-rate estimates by providing additional geochronological constraints. In August, 20111, we re-excavated T7 and T11 from Sieh and Jahns' study, photologged the trench walls (1:10) and collected a total of 30 new detrital charcoal samples from different stratigraphic layers from both of the trenches. Trench logs and radiocarbon results will be presented.

Akciz, S.O., Grant Ludwig, L., and Arrowsmith, J R., 2009, Revised dates of large earthquakes along the Carrizo section of the San Andreas Fault, California, since A.D. 1310±30. Journal of Geophysical Research-Solid Earth, v. 114, B01313-6841.

Akciz, S.O., Grant Ludwig, L., Arrowsmith, J R., Zielke, O., 2011. Century-long average time intervals between earthquake ruptures of the San Andreas fault in the Carrizo Plain, California: Geology, v. 38, p. 787-790.

Grant Ludwig, L., Akciz, S.O., Noriega, G. R., Zielka, O., Arrowsmith, J R., 2010. Climate- Modulated Channel Incision and Rupture History of the San Andreas Fault in the Carrizo Plain: Science, 327, 5969, p. 1117-1119.

Sieh, K. E., 1977, Late Holocene displacement along the south-central reach of the San Andreas Fault, Ph.D. dissertation, Stanford University, Stanford, California, 219 pp.

Sieh, K.E., and Jahns, R.H., 1984, Holocene Activity of the San-Andreas Fault at Wallace Creek, California: Geological Society of America Bulletin, v. 95, p. 883-896.

Zielke, O., Arrowsmith, J R., Ludwig L G., Akciz, S.O., 2010. Slip in the 1857 and Earlier Large Earthquakes Along the Carrizo Plain, San Andreas Fault: Science, 327, 5969, p. 1119-1122.

Wednesday, July 20, 2011

EarthScope is the #1 Most Epic Project on Popular Science Website!

It is very cool that EarthScope has been selected as the #1 most epic science project at Popular Science Magazine/Website. They have an article in the August 2011 issue entitled:  Big Science: The Universe's Ten Most Epic Projects.  It is impressive to have that rating against some other big and exciting science projects, including the Large Hadron Collider and the International Space Station. They used some quantitative ratings and also some qualitative ones such as: What's in it for me? Wow factor, and Scientific Utility on all of which it received a 10. I think that the sense of EarthScope's practicality and its cost to size (variably measured) ratio help boost it. The write up is nice and generally gets the high points given its brevity.

This kind of coverage is really helpful for a program such as EarthScope in terms of visibility. It is the only earth science activity on the list (there is Neptune--ocean science observatory). We can put a lot of energy into outreach, but the readership of something like PopSci will simply dwarf anything we might do...

Since May, we (Matt Fouch, Ed Garnero, Steve Semken, Wendy Taylor, and I) have been leading the EarthScope National Office and I have been the Chair of the EarthScope Steering Committee, so this is very good news and due to the efforts of the prior ESNO staff at Oregon State University.

Monday, July 11, 2011

Subsidence in Arizona measured with InSAR by Arizona Department of Water Resources

An email from the Arizona Department of Water Resources came by today announcing updates to their Land Subsidence Maps.

While the active tectonics of Arizona are rather limited, we do see distributed deformation of a few mm/year across the state with our most active faults in the western Grand Canyon. Jeff Lockridge has been working with me and Matt Fouch and our seismology colleagues in Arizona on an updated seismicity catalog (have a look here: Arizona State University Earthquake Information).

What I often point to as rather interesting ground deformation is that due to groundwater withdrawal and the associated subsidence. With Professor Jim Tyburczy and several former students (Maurice Tatlow, Paul Ivanich, Ken Fergason, and Amanda Perkins), we have dabbled a bit in this topic over the last 10 years. This link includes some of the results from our work.

Scottsdale subsidence feature with 3.2 years (11/15/2007 To 01/08/2011) of subsidence. The maximum is 4 cm. Paul Ivanich worked on the southeastern portion along the CAP canal for his M.S.
West Valley subsidence feature with 6.5 years (03/08/2004 To 09/13/2010) of subsidence. The maximum is 10 cm. Amanda Perkins worked in this area for her M.S.

Wednesday, July 6, 2011

AGU Session: High-Resolution Topographic Data Processing, Analysis and Visualization: Emerging Techniques and Applications

Please consider submitting an abstract to the following 2011 American Geophysical Union Meeting session this fall.  The deadline for abstract submissions is August 4th.

EP13: High-Resolution Topographic Data Processing, Analysis, and Visualization: Emerging Techniques and Applications

High-resolution topographic data collected via airborne and terrestrial laser scanning (lidar) have stimulated new results in the areas of surface processes, hazards, tectonics, and ecology. However, significant bottlenecks to data access, processing, and analysis remain. This session emphasizes technical advancements in high-resolution topographic (and bathymetric) data management, processing, analysis, and visualization, as well as related applications. We invite contributions on software and algorithm development, high-performance data processing and visualization, and emerging analysis techniques.

Sponsor: Earth and Planetary Surface Processes (EP)
Co-Sponsor(s): Geodesy (G), Hydrology (H), Earth and Space Science Informatics (IN)

Christopher Crosby
San Diego Supercomputer Center, UC San Diego

J Ramon Arrowsmith
Arizona State University

Michael Oskin
UC Davis

Tuesday, July 5, 2011

Remembering Kurt Frankel: post at OpenTopography

Many of us heard the sad news of the tragic passing of Kurt Frankel this weekend.

Chris Crosby and I put together a memory of him at OpenTopography: blog post.

Sunday, July 3, 2011

Old blog entries worth keeping

I rescued a few entries from my old blog that seem to be worth keeping (at least I look for them occasionally). The old site is so bad that I just printed them to PDF, so the quality is not really there, but at least there is a record.

Musings, personal items, and miscellaneous

Students and teaching


San Andreas fault

High resolution topography

Other topography

Grand Canyon

Starting a new blog; moving from the old one

Hello world!

I don't want to sound too presumptuous with the name Active Tectonics, but that is the sub discipline of earth science that interests me (study of deformation of interest to society). It is also the name of my research group at Arizona State University (ASU): Furthermore, my old blog was rather unimaginatively named arrowsmith blog. And, as you would see if you clicked on that link, the web site is very slow, has security problems with most browsers, and is no longer supported by ASU.

I am not a big blogger, but I like to put ideas, opportunities, other tidbits out there that might be of interest. I started my last blog August 15, 2007 and had about 60-70 posts.

To write a blog requires of course that one has something interesting to say. I hope that will be the case here. I invite comments on the posts. May they promote clarification and collaboration.

Here are number of links to my local piece of cyberspace: