Caroline Hagan Webb is a student at Brown University currently completing her research at National Security Technologies under Cathy Snelson.
I am working on the Source Physics Experiment at the Nevada Test Site. The goal of SPE is to develop better ways of detecting small explosions so that we can reinforce the Comprehensive Nuclear Test Ban Treaty once it is adopted. I am using geophone data from the last SPE shot to better map the test area. The part of the test site where we are testing is called Climax Stock and is made of Granitoid rock. It has a perched water table and faults in it, which perhaps I will be able to see in the refraction data. One thing that knowing the layout of the stock will help is trying to determine the cause of the S waves that have been found from previous explosions.
Hi! So it's been a long while since I posted. My last two weeks at NSTech were really hectic. Since I had finally gotten SPW and had to redo all of my picks once I got some help from Rob Abbott, my goal was initially to try and make a model from scratch before leaving.
But then I got an opportunity to do more field work, so Cathy advised me to put off the model and go out into the desert to get some useful experience.
So for week 8 I got to calibrate refteks and spend some quality time at BEEF (Big Explosive Experiment Facility). I tried to stay to watch them explode a U-Haul, but it ended up taking too long and we had to leave before they did it. (I did get to watch some nice videos of it afterwards though). Back at the office I started inputing some shot location data from field notesw into my model and figured out how to work around a glitch in MacRay.
In week 9 I went back to the test site 3 more times to install new trillium seismometers. These are really sensitve and had to be perfectly level. They were also placed at farther distances from the test bed than the geophones and refteks I had been working with before, which means I got to go on the scenic route of the test site and do some quality hiking. I thought it was fun, although I did feel bad for Ryan, who had to do all the driving. There were a lot of craters, rocks, fences, and old radioactive equipment to dodge and weave through. Plus he was the one who had to lift open the covers on the trilliums, which had a tendency to have animals living in them (mice, lizards, and 2 blackwidow spiders). In addition to the inhabitants of our sensors, I also saw some wild horses and a coyote!
And back at the office, I first made a model to fit the picks that I had. But then I found out I had to redo all of my picks, so I just barely had time for that before I saved everything to an external to take home with me. Plus that weekend there was a hurricane back home, so I had some trouble rushing to get the last flight I could that was still going to Boston, but I made it home in time to visit my aunt's beach house for a great view of the giant waves and intense wind!
Anyways, so I am still in the process of finishing my model back in RI. It has taken me a while to get restarted, since I have been busy with my senoir thesis, but hopefully I can get a good model that makes sense before AGU.
Looking back at my goals, I am really glad I got to do some field work, and I had a lot of fun doing it. I also am glad I had to carpool with my advisor, because it helped me get to know her a little better, since we usually weren't in the same building during the day. Because of my hand injury, I had a lot of time to read seismology books, so I think I have learned a good deal about seismology. I also had a good time in Las Vegas--I think my favorite place was visiting the Belagio because everything was beautiful and magical looking, like some sort of candy land or something. I also got to try out a few computer programs: JRG, SPW, Macray, and I played around with unix and matlab. I am still working on analyzing my data, but I'm optimistic about it.
Looking back at my blog, I definitely had some frustrating times, but in the end I did get a lot of experience, and got to learn about seismology from a lot of different perspectives- from doing fieldwork to reading papers to learning new software to sitting in on research planning meetings to figuring out how to work with bureaucracy.
As for my future, I'm still undecided. I now know I want to go to grad school in geophysics, maybe even for seismology, or maybe focussing more on earthquake mechanics. I am really excited to go to AGU this fall and am glad I have become a part of the geophysics ccommunity so that I can learn more about all the exciting research out there.
So, after spending all day Monday begging, pleading, and running around to people's offices when they didn't answer my calls... I finally got SPW!!!
This week Cathy's been away at Washington DC, so I''ve been pretty much on my own. She did help me start using SPW before she left, and hopefully I've been picking first arrivals correctly since then. I made it through the 100 shots of the minivibe data and wrote a script in matlab (which I also recently got on the "big Mac" I'm using-- way easier than tyring to do things in excel/numbers) to convert the pick files into a format that Macray will happily read. Next I have to use Macray to forward model the layers and velocities of the granitoid we are looking at.
On the fun side of things, I have had a rental car this week, so I get to do more things. I tried driving around during my lunch break and ending up at a casino called "The Cannery". Of course I didn't want to spend real money, so I signed up for a free membership card that usually comes with some slot credits. I happened to be lucky that day, so they gave me 200 free credits, which I have managed (through hard work/gambling efforts) to convert into over a hundred dollars of real money!
Yesterday I drove out to Red Rock Canyon, which has all these nice iron-red layers of aeoliean sedimentary rocks (not sure how to spell that, but I mean the kind that happens when you have wind and sand dunes) it was almost dark when I arrived so I only had time to climb down into the rocks, wander for a few minutes, and climb back out before doing the "scenic drive" around the park. Apparently I caught the bad key karma that my mom said she was having this week, because somewhere along the way I lost my apartment keys. I'll have to have my roommate take me to copy his today.
Ooh, and also I get to go to the test site again on Monday to calibrate refteks (and I do count as a whole person now).
over and out.
My advisor has just told me that she wants me to view the data in wiggle form, not as the color-coded amplitudes that the program I have (JRG) makes. This means I have to wait for SPW to come in order to start processing my data, which might hopefully come by the end of this week.
In the mean time I am working on my agu poster and hoping I will be able to actually do my picks and make my model before the end of the summer.
I finally got to go to the test site this week, and it was about as awesome as I thought it would be. I only got to go on Tuesday and Wednesday, but I don't mind becasue it does get hot out there.
My day started at 4:45am when I had to leave my apartment to walk to the bus stop. Then I got to ride this really comfy bus until about 7; I got to sleep a little and look at the amazing views of the mountains at sunrise. Then the guys I am working with (Ryan Emmitt and Bob White) drove me out across the test site (which is bigger than Rhode Island) to area 15. There was lots to look at in the test site: craters of varying sizes, radioactive warning signs, old equipment and trailers they don't use anymore but can't throw away because it's radioactive, the war room, other trailers they do still use, and pretty tilted strata.
Once we finally got to our test bed (where the SPE explosions happen) I went with Ryan out on a Mule (a small ATV), and we got to go off-roading to get the geophone receiver locations. Some of them we had to hike to because they were too far up hill, but that was fun too. My only job was to record the data on whether the geophones were working/ if any animals had eaten the cables. This means I had plenty of time to play with rocks. I saw lots of huge K-spar phenocrysts in the quartz-monzonite, nearly perfect calcite crystals, quartzite, some of the sedimentary layers, and lots of pretty colorful welded tuff. Oh, and also we saw a snake.
On Wednesday we finished checking all the geophone lines, and after doing a brief gps survey of the slope next to the test bed, I got to go on a tour of the test site. I got to see the sedan crater (part of the nukes for peace program), some more equipment that normal people don't get to see on the tour, the BEEF (big explosive experiment facility) bunker, and some videos of explosions. It was a pretty good day. I kinda wish I was allowed to take pictures.
Just to add to the awesomeness of my week, I have finally gotten access to one of my data sets (minivibe refraction data)! And with help from rob Abbott (an SPE person from Sandia) I've gotten it in a form that can be read by the program I have, and I can even reasonably see first arrivals in it! Now I get to start going through and really playing with the filters and times so I can make a good model.
Things take a very long time to get through all the security and beaurocracy here, longer than the time it would take an ent to say this sentence. So I'm still waiting for my data, which hopefully will come in this week. Meanwhile I've been working on my AGU abstract, which I have to finish this week in order to give the NNSA time to review it and give me clearance before I'm allowed to submit it.
I've also been doing a lot more reading; my host gave me 5 geophysics books to look through, two of which are good enough that I've considered buying my own copies.
On the exciting side of things, I'm going to get to go out to the test site next week! I still don't technically count as a whole person (they have this "two man rule" where you need at least two whole people every time you go out to the site) cause of my hand, but since there's already two other people going, I get to come along and take notes for them. We'll be looking at the geophones I had found problems with back when I QC'd their signals.
So, looking back at my goals, I'm doing pretty good on #7 (I'm still in Physical Therapy but making progress), and have making lots of headway on #3.
So far I have been doing a lot of reading and preparing for my data. I have been reading about the CTBT, and the geology of the test site. I have also gotten some software to play with. Since it is taking Matlab forever to get through security (over a month) I have been given one of Cathy's colleagues programs to help me choose first arrival times. Then I will be using MacR1D and MacRay (the 2D version) to forward model the velocity structure and see if it matches with the travel time plot. So far I still don't have the SPE data I need, but they are working on getting it into SEG-Y format so that I can open it. I've been pretty successful at playing with the sample data, though, and I have figured out how to convert it from one program to the other.
So I am finally in Las Vegas and have actually been to the place I'm working! I still don't know much about what data I'll be looking at and specifics because my advisor has been in meetings since I got here. Today I was actually not allowed to go with her because of classified information related things. But anyways I got to see the large mac I'll be using, and went through the online training so that I now know what to do if I run into a desert tortoise or radiactive things (hopefully I won't see any radioactive tortoises). Plus I got a security briefing and got to sit in on a meeting about the source physics experiment and how they plan to do their next explosion.
So now my only issue is finishing trying to get a new apartment that is within reasonable range of where I'm working, and hopefully the one I saw today works out.
1. get experience in doing field work
2. get to know my professor
3. have fun in Las Vegas
4. learn how to use more computer programs well
5. get/analyze enough data to make a poster
6. come out knowing more about seismology than before and be more confident about how to use it.
7. have my hand heal enough that I'm allowed to do field work.