My project is focused on many years of data collected in southeast Alaska as part of STEEP. I will be calculating teleseismic P-wave travel time delays using dbxcor for many different events on multiple seismic stations. This data processing will take up the first few weeks of my internship. Once all the data has been processed a 3D tomography model will be made of the area to get a better understanding of the plate tectonics in the area, which are quite complicated. There have been other studies that have collected data in the area including some active source studies. If there in enough time the hope is to integrate that data into the tomography model as well.
It has been a long summer, but I have learned a lot. I feel like I started out a little bit ahead of the game when we got to New Mexico since I had already taken two seismology classes and done 3 weeks of volcano seismology research, but I soon found out that I had tons more to learn. I had never worked with UNIX or GMT and they seemed really intimidating.
Now I am at the end of summer and I have to say while there were some challenges I feel like the things I was afraid of in NM weren’t nearly as difficult or scary as I thought they would be. And now since I do know UNIX and GMT I’ve been help other student I know learn it too.
I feel like I accomplished my goals for the most part. I am a little disappointed that I didn’t get to do any of the 3D tomography while I was there, but I still got some really good results that I am really happy with. And I will still probably get to see the tomography results even though I didn’t get to create them.
Since I finished my internship way back in July I have had three more weeks of doing MORE seismology research with Greg Waite back at Michigan Tech where I go to school. I am studying a volcano called Pacaya which is located in Guatemala. Since I have gotten back I have produced a very shallow (~500m deep) velocity model. I’m thinking I will write a post final blog all about this for those of you who are interested.
In all I have learned some great research tools this summer ranging from UNIX to independent problem solving (aka fixing problems when an advisor isn’t there to help). These tools will be really helpful once in grad school.
Today turns out today is my last day. I was originally supposed to work through the end of the week, but plans change. My advising professor has to go out of town for the rest of the week, which would have left me here with no much to do since I have some figures for my poster ready and I finished my abstract this morning. I still have details to figure out so really I am not done with my internship, but I am done with my part here in Indiana. I will be driving back to school tomorrow, where I will go back to the research I was working on earlier this summer. My research there is also in seismology, so not really that big of a change, just a different location and another abstract to work on.
For the rest of you who are finishing up and writing abstracts, I wish you good luck!
Here is one of the 100+ maps I made in GMT of the raw residual data. The scale bar is in seconds, so it implies there is a difference in arrivals of 2+ seconds between some stations. The giant white arrow points toward the event location, which is kind of confusing, but it is what I had for data and I didn't feel like adding 180 degrees. As you can see the station coverage isn't very good and there are some terrible edge effects and other artifacts in this griding method. But the good news is all my results so far are really promising so far. Also due to time constraints it looks like I will not get to put all my data into a tomography model. After I leave my advisor is hoping to do the tomography work and send it to me as he does it. He is also hoping to finish processing the data from end of 2008 through this past June and put that into the tomography as well.
Since I posted just a few days ago this is a pretty short entry. But, I will hopefully have another entry later this week with some pictures of the cave I went on the 4th of July as well as some other updates on how my project is coming together.
The numbers are in! I have finished processing data from 2005 to 2008 in Alaska. The original goal was to go up to current day (or at least until June when I downloaded data) but due to time constraints of both me and my advisor we decided stopping at 2008 would be a better choice for time and more than enough data anyway. We have something like 2000 events and 23,000 individual arrivals from all the events on all the stations.
On Friday we worked together using GMT and shell scripts to plot up the top 100 or so events that had the most stations with picked arrivals. These make pretty rainbow colored plots with an arrow pointing in the direction of where the earthquake occurred (that took some teamwork and some crafty coding to get the arrow to change directions on every plot). We have removed the mean residual from the data so it is just a way to show with raw data if arrivals are early or late. So far it looks really promising! There are some really clear fast areas and slow areas, that seem to be consistent from all directions. The even better news is that is also fits with the previous models of what is there.
It is really cool to see some pretty maps finally as a result of weeks of black and white data processing looking only at waveforms. Now I need to make them look “prettier” as my advisor puts it, or in other words make them ready to put into my AGU poster. This will be my task this week since my advisor will be gone all week once again due to field work involving a training session on installing a seismometer. I could have gone with, but I feel like I have too much to get done, and I’ve already installed a seismometer in New Mexico I will provide some example plots sometime later this week since I don’t have any of them available to me while I write this post.
As for other visuals…..
Regarding requests for pictures of my field work:
I don’t have any good pictures of my field work, especially since I didn’t do anything exciting. Really. All I did was:
1. dig a hole
2. pour in cement
3. put a vault in the hole in the cement
4. pour mortar into the vault
5. put the cap and the vault and pour dirt around the vault
6. cover it with a tarp and then put dirt over the tarp
The fanciest equipment used was a hand auger and a posthole digger. However here are the cool cliffs I drove past while on the way to the site where we couldn’t dig a hole due to a locked gate.
Above is the top part of the cliff where you can see some awesome layers
Below (sorry it is so small, it was to large of a file otherwise) is a better show of how tall the cliff is. Look at the telephone poles for reference, they came up to about the top of the the first white cliff face, so the cliff hight was eaily double that.
And just for fun, here is what one site looked like. Not exactly exciting is it?
Also I realized that I completely left out the fact that while my parents were here my Dad and I went to a limestone cave created by Karsts landforms in southern Indiana. I’ll need lots of room for pictures of that so it will have to be its own post maybe tomorrow or next week.
It has come time for me to report back on my last two weeks since my post last week was really quickly typed up (with no spell check, sorry about all the mistakes). My week before 4th of July weekend consisted of me processing more data while my professor went out and did some field work. While he was gone I worked hard to process data. Unfortunately I was thinking very clearly and made a huge mistake that I didn’t know how to fix on Tuesday afternoon. Luckily after about an hour of thinking followed by another hour of trial and error, I figured out how to fix it all by myself! My Professor came back on Wednesday evening and we did the IRIS review sheet thing and he told me he was proud I was able to solve the problem all on my own. In the end I did lose about one days worth of work though.
My family arrived in town late Wednesday night. I took half of Friday off and went with them to finally wander the downtown shopping of Bloomington, IN. There is some really fun stuff here and I will have to go back again I think. We also drove up to Indianapolis and visited the zoo as well as the NCAA museum. It was fun going to the museum because they had a picture of my school’s mascot (go Michigan Tech Huskies!) and it was the only picture where the mascot was wearing hockey skates. So appropriate! We also fit in some more shopping, some minigolf (despite a heat index of 110) and lots of good food.
My family left on Tuesday morning while I left for field work in Southern Illinois digging holes. The field team consisted of me, one IU grad student, and two other geology undergrads from Purdue. We worked out of Carbondale, Illinois and I got a real good look at lots of corn and soybean fields and lots of dirt. I have also never sweated so much in my life! But the work wasn’t too bad. I spent a lot of time at McDonalds while I was there because it had free wifi. On my last day down there one of the guys from Purdue and I were sent to a site really far west border of Illinois. Unfortunately we couldn’t reach the owners and the gate to the property was closed, so we couldn’t dig a hole, but the drive was gorgeous. We drove past some huge gorgeous limestone cliffs. The best part was that the cliffs had mines in them that really cold air came gushing out of. It was like driving past giant refrigerators and it felt wonderful! The cliffs were on the edge of the Mississippi flood plain, which was still mostly flooded. I was so awesome seeing the huge flood plain compared to the size of the Mississippi I am used to in Minnesota.
I got back from field work Saturday afternoon and went to my professor’s house for a party celebrating one of the grad student’s defenses he had done that week. It was pretty fun and dessert was delicious. I am back to processing data now as well as beginning to look at the tomography code. The tomography code seems like a challenge to work with, but do did the data processing at the beginning and that’s easy stuff now. I’m hopeful I can lean it and get a good model out of it in the next few weeks.
Well I think I’ve typed enough for two weeks now, and my fingers are getting tired. Also my internet died at my apartment, so all my internet time had to be done either at my internship or somewhere with free wifi (I’m at Barns & Noble right now, I’m sick of Mcdonalds). Hopefully I can get the internet at my apartment fixed by this weekend. Who knew modems could be so tricky?
I will try to do a longer entry later, but I'll give you the short version now. My family came to visite me and got here Wednesday night and staryed until thismoreneing when took off back home. This was a fun visit and we did some cool things I'll talk about later. The bigger news was that Wednesday evening (when I got to meet with my advisor the one hour he was here last week) he told me I would be going out and doing field work starting today (Teusday) for the entier week.
So I have been a bit overwhelem with being busy and with the really hot and humid weather here. We had a heat index of 100 degrees over the weekend. It should be a little better this week while I am installing seismometers, but some how I think it will feel pretty hot out while I am digging holes all day.
I will give you more info on my previous week and on how my feild work goes this weekend after I get back from field work on Saturday.
It turns out my worry about storms last week was unfounded. While it did storm again, and the power didn’t go out, the data I was downloading managed to find some issues of its own. Of course this happened on Wednesday, the same day my advisor, Gary Pavlis, left town for the week, which means I was lost. Solving the problems of how to obtain data using UNIX commands was beyond my scope of knowledge, so I just had to wait until this morning to see what could be done. In the mean time Gary found a way to start obtaining some of the other data we needed.
The bottom line is that as of this morning I have data! At least for 2008 anyway, and that is going to take me at least a week to process which gives me lots of time to work on obtaining the rest of the data I need.
In the mean time I have been going out and exploring Bloomington on the weekends. I went to the farmers market and bought some tasty veggies and some delicious clover honey. I have also made my way over to the local mall to take a look around and I have already done some shopping.
This last Saturday the weather was especially gorgeous. It was partly sunny with a high temperature of 75 degrees (by my northern standards this is a nice warm day). It seemed perfect to go hiking. So after getting lost due to construction, changing plans about 3 times and having a nice drive I finally found a national forest where I could hike for free on some great trails in the woods. It reminded me of being farther north, and I even saw a while tailed deer on the hike.
This whole week will be filled to the brim with data processing, so I guess my only goal for this week is to get as much done as possible. It will be a repetitive and long task, but with some occasional breaks hopefully I won’t get too worn down by it. At least I have gained confidence after this last week because every time I do get lost I seem to find another answer, even if it wasn't the original answer I was looking for.
Week two is over and week three has started. I worked really hard last week and finished processing the data from 2005 up to 2007. I was really happy to have gotten through all ~500 events in a decent amount of time although me and my advisor Gary Pavlis still need to go back and fix the first ~300 events which were not saved correctly by the program I was using. Now, I want to get a start on to data from 2008 to present day. Problem is that it takes forever to acquire the data, and by forever I mean it probably won’t even be ready by Friday of this week. It took me just over a week to get through those 500 events, and I just found out today that from 2008 to present, there are more like 2000 events! I wish I could get started but I probably won’t be able to start until next Monday.
So what do I do in the mean time? Well, I’ve finished some extra background readings that I received when I got here. Next on the reading list is an entire book of tomography, but I was told I can skim it. My real challenge that started today was learning and using GMT and c shell scripts. I worked on them for about an hour and a half today and I was totally lost. However, I’m making it my goal this week to really try to read about this stuff so I can learn how to use it effectively. Hopefully, I will master it enough so that I will be able to solve some challenges on my own.
My biggest fear in all of this, strangely enough, is the power going out. I’ve been leaving the computer on at night to download more data while I am gone. However, we keep getting thunderstorms, and they are pretty strong storms at that. The power already went out once, but that was before I had started downloading data, thankfully. But now, I just don’t want to lose any time since the download takes so long! I really hope the weather calms down so I can sleep better at night.
This past consisted of a lot of learning both in and out of the computer lab. First was tackling the city of Bloomington, IN. It is not a big city or anything, but it is much larger than the city where I go to college, so all the one way streets and increased amounts of traffic can make things confusing.
Lucky for me UNIX has not been nearly as confusing as I thought it might be. It turns out that all my MATLAB experience pays off in terms of having at least a basic knowledge of how some programming works. After a few days of computer troubles and then lots of data transfers by Thursday afternoon I was processing data! It feels good to be actually working on the real data and to be on my way through the very large amounts of processing I need to get done. The program I am working in, dbxcorr, is really nice because I only have to pick arrive times once per event instead of for each seismic station. This really helps when I am often looking at 25 or more station recording for one event. Unfortunately no program is perfect and I seem to end of crashing it fairly frequently. But so far my patience has been strong, so I just re-start the program and keep going.
The goal for next week is defiantly to process as much data as possible so I can get to the tomography sooner. I want to accomplish as much as possible while at this internship.
I am excited and nervous for my internship in Indiana doing a 3D tomography of the crust in the subduction zone under Alaska.
As the week of orientation ends, I am preparing to had off to my Internship to accomplish great things. Those great things are...well I'm not entirely sure yet. My first goal I guess is to become well versed in the subject that I will be researching. I find the more I know about something the more interesting it becomes to me, so have a broad knowledge base about tomography and subduction in Alaska would be a good place to start
My next goal Is to get a better grip on UNIX. it doesn't seem that complicated from what I have learned this week, but I know I need to really master it which could still be quite a challenge. I can see how it can be a valuable tool but to use it effectively I have a lot more to learn. I have worked extensively in MATLAB but I need to expand my programing horizons.
The last goal I can think of at the moment is to learn as much as I can and also to enjoy the summer. this might be a bit of a challenge because I know I might get a bit lonely all by my self, but I hope to find some fun adventures and new interests to entertain my self with. I can't wait to sit down In Indiana and work out some well defined goals for my research. I will have to write down those goal once I have a better idea of what they are.
I will be in Indiana soon!