Monday, December 1, 2014

November 30, 2014 M4.7 earthquake between Sedona and Flagstaff

Last night, a M4.7 earthquake occurred between Flagstaff and Sedona (just west of Munds Park). I hope it was not too scary for my friends and colleagues. It sounds like it got their attention! I agree with Professor Brumbaugh from NAU who said: "It was a large enough earthquake to be felt, but not quite large enough to really get too concerned about" (link).

Arizona Geological Survey colleagues (some ASU alumns!) are responding. Here is a blog entry from Arizona Geology on the event. Here is a nice map from them with better locations:

The USGS shakemap indicates that light shaking is reported from north Phoenix to north of Flagstaff. If you know someone who felt it; tell them to go to that site and record their perceptions.

Here is the seismogram from Tucson:

and if you go to the IRIS page on the eventyou can hear it!

The earthquake occurred in an area where there are some active faults, most notably the Lake Mary fault system south of Flagstaff. Here is the epicenter on a map of USGS Quaternary Active Faults:


Here it is with historic seismicity (from Jeff Lockridge). There was an M3.5 within a few km of this event on November 25, 2014.
Here is the epicenter on the Geologic Map of Arizona:
The epicenter is right on top of the Oak Creek Fault. So it could be associated with that fault, but it would need to be located further east given the eastward dip of the Oak Creek fault. I see that the focal mechanism is available now from the USGS and it is a NE-trending mostly normal faulting event. The Earthly Musings blog has a nice entry on the Oak Creek Fault. Here is the earthquake on a compilation of active faults and earthquakes that I put together:
Here is the PDF. There have been some earthquakes in that area over the years.

Additional links:

I will continue to update as I learn more.

Monday, November 24, 2014

Planetary Volcanology field trip to the Pinacate Volcanic Field (November 22-23, 2014)

I joined a field trip to the Pinacate Volcanic Field in Northern Mexico this past weekend. It was a part of the Planetary Volcanology class taught by David Williams and Amanda Clarke. It was beautiful and very interesting. I had never been there, but just stared at it on google earth:

In this post, I present some field photographs from the tour, followed by a few slides from Amanda Clarke from a lecture on Water-Magma Interactions:

Crater Elegante

The Pinacates are in a biospheric reserve: http://elpinacate.conanp.gob.mx/.
Crater Elegante: nice example of the phreatomagmatic features in great evidence.
Nice bomb sag in the surge units.
Amanda Clarke explaining the eruption-related features.
Model for Crater Elegante formation.
As we drove around, we saw some nice tephra that Amanda got excited about.

Conos Tecolote y Mayo

Overview looking south at the Sierra Pinacate. Note boundary between the more vegetated and tephra covered flow to left with fresher looking darker flow to right.

Cerro Colorado

View to the northeast looking at Cerro Colorado (feature to the right middle ground).
Cerro Colorado layered mostly surge deposits (view to east).
Cerro Colorado layered mostly surge deposits (note various clast compositions).
Cerro Colorado view towards the southwest; note nested "hippodrome" of late stage eruptive center(?).
Some lapilli--mostly armored, a few accretionary.

Water - Magma interactions

Amanda shared a few slides with me.
Cool slide showing the eruption energy versus water/magma ratio and the various phenomena and forms we may observe.
Forms versus eruption energy with increasing interaction with water.

Saturday, November 15, 2014

SoSAFE and Earthquake Geology Geochronology workshop report (Southern California Earthquake Center)

Kate Scharer (USGS), Mike Oskin (UC Davis) and I organized a geochronology workshop for the Southern California Earthquake Center community this fall. We emphasized methodologies useful for investigating fault slip behavior over time scales from 102 to 106 years. That included Terrestrial Cosmogenic Nuclides, Uranium Series, and Optically Stimulated Luminescence. We did not talk so much about 14C given its relative maturity, but we certainly recognize its continued value.

Kate lead the charge on the completion of the workshop report. It has a nice summary of the topics covered (here is the original agenda). I had a sense of a real acceleration in the number and quality of applications of the methods and the resulting rich depiction of deformation rates and their variations across time and space in Southern California. I was particularly moved by the climate modulation on the development of landforms (alluvial fans, channels, etc.) that serve as markers as well as the possible temporal coherence of wet and dry times across the region. I think that this modulation and coherence can be exploited with more intensive application of geochronology.

I learned a lot more geochronology, especially having just been at the EarthScope Geochronology Institute a week or so earlier--note that the talks and some of the videos are up (where we covered some similar topics and where Kate was a speaker on 14C). It was very nice to see many SCEC friends and colleagues.

Tuesday, November 11, 2014

Fall 2014 Workshop on the Future of the Amphibious Array

Led by Professor Geoff Abers (speaking above), we organized the Workshop on the Future of the Amphibious Array which was held at Snowbird in the Wasatch Mountains of Utah--and which I remember well from early EarthScope meetings.

The workshop charge was to make the case for further amphibious experiments (emphasizing the idea of crossing the shoreline). We need to articulate the case for integrated amphibious science. And, we were to evaluate the Cascadia experience. We were guided by the EarthScope Science Plan and by the GeoPrisms planning documents. I also helped summarize a breakout session. Here is the PPT.

Greg Anderson from NSF was traveling with Silverwing:

I had a decent view of the Grand Canyon on the way home:

GSA Annual Meeting 2014

I spent almost a week in Vancouver, CA for the Geological Society of America Annual meeting. It is a very beautiful city with dramatic views and great food.

--view from the convention center

Becky Flowers giving science motivation talk at the EarthScope Geochronology and the Earth Sciences Institute and short course. The short course was my main purpose for being there as I helped to organize it. I learned a lot. For example, a date is an outcome of the analysis and calculation, while age is an interpretation (S. Bowring). I gave a welcome (PPT) and an EarthScope science motivation talk (PPT).We kicked off the Gecchronology student award program: PPT. We have a number of videos of the presentations and the pdfs, etc. which should be on line soon.

I also enjoyed seeing many old friends and colleagues.

Fall 2014: PATA-Days in Busan, Korea

I had a wonderful trip to Busan, Korea for the Paleoseismology, Active Tectonics, and Archeoseismology (PATA Days) meeting. I really enjoyed it. It was great to see old and new friends, catch up on the latest developments, and to travel in southern South Korea.
Here is a presentation/overview I made for my students and colleagues for our seminar:
PPT
Here is the paper I wrote for the meeting: pdf.

I spent some nice time with my friends Koji Okumura and Shmulik Marco:

It was also an interesting trip because my father was based at the Pusan East (K-9) air base in 1951. He was curious to hear about the trip and mentioned that he turned 21 there. He said they played a lot of cards and that a few times he got to go off base to help his friends who worked at a reservoir.

Monday, September 29, 2014

Some TU Dresden SfM and lidar links

I got a nice tip from Univ.-Prof. Dr. Klaus Reicherter about some good structure from motion (SfM) and lidar links at the Technical University Dresden:


I also note for reference that we have the OpenTopography Tool Registry