Friday, September 12, 2008

SCEC Day Two

It would appear that I have failed miserably at live-blogging the SCEC conference. That said, I will still post about each day at a time! Just, you know, offset by a few days. I'm studying strike-slip faults; I'm good at offset. Yeah...

Day Two of the conference included a field trip for students only. Our advisers and mentors all got to sit in the too-cold hotel and listen to organizational talk, while we got to go hang out in Anza-Borrego Desert State Park. Despite the 110-degree heat, we students clearly got the better end of the deal.

The purpose of the field trip was to look at features of the San Jacinto Fault, and the trip was led by a PhD student whose dissertation is on the particular part of the fault we visited. I got the impression that, given how the trip leader described what a scarp is and how it formed, and how streams get offset, that this trip was more geared toward people who had not seen fault features up close and personal before. That said, I am always glad for a chance to poke those features, particularly in places I haven't been before! The San Jacinto in Anza Borrego has many strands, some separated by a couple of kilometers, some only by a few feet. The latter manifested itself by chopping an alluvial fan into narrow shreds; the shred moved by the most active strand of fault is also marked by a four-foot scarp. There were also offset streams on all sorts of scales. The trip led us from one that was only deflected by three feet all the way to one that, rivaling the San Andreas' Wallace Creek on the Carrizo Plain, was pulled over a hundred feet to the right. That is quite a testament to the power of this young and active fault!

(I took a ton of pictures of these features, but all the good ones are in the form of panoramas, which I have not yet stuck together yet. I'll be posting them once they're done!)

We took about half an hour for lunch, then continued on to look at a mylonite zone high on a ridge. In order to get there, the tour bus had to go on a narrow and winding road that was clearly not designed with tour buses in mind. This made me nervous in and of itself, but I nearly started shaking when the bus turned toward the edge of the cliff. I realized, only when we did not start falling, that there was a turnaround here and we were actually trying to park. Parking was successful, but that still wasn't a shock that I needed. The mylonites in question were down the cliff from the bus, and only about half of us (myself included) actually climbed down to look. I was disappointed that they did not clang harmoniously beneath my feet (as Kim has observed with a different mylonite zone), but they made up for it by having very clearly defined shear/scrape marks, even on top of the elongated mineral grains. This is not something I'd seen up close before, and I thought it was very very cool.

On the ride back to Palm Springs, I was still so excited about the trip that I was sure I'd be awake and alert enough to catch the end of the Southern San Andreas Fault Evaluation (SoSAFE) workshop, but as soon as I got back into the air conditioned hotel, the exhaustion of spending several hours outside in the desert in summer hit me, and I decided a nap would be the obvious use of my time (or rather, my body decided this for itself). The most useful thing I did for the rest of the evening was help a friend of mine put up her poster (there were two sessions, hers was in the first, mine was in the second). I looked at a few posters as well, but my attention span was shot from tiredness, so I mostly took mental notes of which I wanted to come back to the next day and look at in more detail. I was not too braindead to appreciate the plate tectonics puzzle game for little kids, though. I think I want one, nevermind that I'm 24!

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