I’ve started to develop a backlog of things to write about, and seemingly less and less time to actually write. Most significantly, probably, I need to write something (anything!) about my trip to Kyrgyzstan. I’ll start with some overview stuff here, and talk about specifics in later posts.
Q: Whaaat? You went where? Why? How? Where the heck is Kyrgyzstan, anyway?
A: Our department has a fund for sending a bunch of students to study geology in a remote place every couple of years. It’s always a place where one of our faculty has an active research project, and it switches each time. The last trip was just before I got to UO, my adviser led a trip to Spain and Morocco. This year the destination was Kyrgyzstan. Kyrgyzstan is a small central Asian country sandwiched between Kazakhstan to the North, China to the East, and Tajikistan and Uzbekistan to the South and West respectively. More intuitively, it’s here:
Q: What active research are UO workers doing in Kyrgyzstan?
A: Ray Weldon, one of the UO geology faculty members, has been working for over 20 years on a continental dynamics project with Dr. Kanat Abdrakhmatov, the director of the Institute of Seismology at the Kyrgyz National Academy of Sciences. They’re trying to understand the mechanisms of deformation that have uplifted the Tien Shan mountain range, and by proxy understand seismic hazards associated with the active tectonic deformation. There have also been countless grad students over those 20 years who have done their dissertation work on that project. Most of which has been geologic mapping of some of the major fault zones. Most recently, Ray has been trying to interest the paleontology group in helping to pin down absolute ages on some of the important rock layers by identifying fossils in them. This year my friend, Win, got a grant through the Fulbright Program to work towards that goal by looking for fossils in the Tien Shan mountains for 10 months next year.
Q: Why research Kyrgyzstan? What’s significant about those mountains?
A: The Tien Shan mountains are the northernmost extent of the Tethyan Orogeny, a result of the continental collision between India and Eurasia which also created the Himalaya. Both mountain ranges are the result of horizontal compression of the Asian continent: as it gets squished horizontally, there’s nowhere to go but up (and down, but these structural geologists don’t usually care about that). The Himalaya have been around for a long time now, and the Tien Shan are relatively young. The Himalaya are now increasingly inactive, and most of the modern deformation is taking place farther North.
Currently, around 50% of the total shortening of the Eurasian continent, is taking place in the Tien Shan . That shortening has to be accommodated somewhere. Deep in the crust, the rock is warm enough, and under high enough pressure, that it can deform slowly over time, but near the surface that stress is accommodated through sudden ruptures, ie. earthquakes.
Just as an example of the active seismicity, according to the USGS earthquake catalog, http://earthquake.usgs.gov/, there have been 21 earthquakes greater than magnitude 4.0 in the Tien Shan in the past 30 days.
Kyrgyzstan might be the most seismically active region in Asia, but the record of historic earthquakes there is surprisingly sparse. As the population has grown, and urbanization increased since the beginning of what everyone there just calls “soviet times”, building and infrastructure regulation needs to start taking in to account the possibility of very large earthquakes, but nobody knows how often such an earthquake might happen, or how big it could be.
During our trip we learned a bit of everything about Kyrgyz geology, but for most of the trip we focused on understanding the history of uplift and deformation, to better constrain the net rate of movement on the major faults, and ultimately determine which ones could present significant seismic hazard.
Of course we also got to meet lots of very cool people, and see all kinds of beautiful places; and meet some shady people, and see some very ugly places, but more on all that in later posts!
 Abdrakhmatov, K. Ye, et al. “Relatively recent construction of the Tien Shan inferred from GPS measurements of present-day crustal deformation rates.” (1996): 450-453.