This summer I am creating receiver functions for seismic stations along the Ryukyu arc in southeastern Japan. After I have made the receiver functions I will be doing some forward modeling to try and determine whether any serpentinization has occured in the upper mantle of the subduction zone. I am working under the guidance of Dr. Maureen Long with the help of one of her grad students Erin Wirth.
With less than 2 weeks left here in New Haven before I head back to South Carolina, I am starting to tie up some of the loose ends on my project. The forwarding modeling code has proven itself to be non-intuitive and frustrating at times but it is very satisfying when you get a feature to match. I have been spending most of my time trying to create a model for the KGM station, which is one of the middle stations along the Ryukyu arc. It is interesting to see the features that show up and change across multiple stations. There is one in particular the we see on the northern three stations that I am going to attempt to model next (wish me luck).
I just submitted my AGU abstract yesterday (glad to check that off the list). Unfortunately the AGU dates are the week of my finals but hopefully I won't have to much trouble working it out. I have also started putting my poster together in my spare time. I don't have much more than a layout with my name and abstract in there yet but at least it is a start.
Went into NYC to visit an old friend over the weekend. Took my first ride on the NYC subway system (a little sad considering I have lived in the NE most of my life). It was an experience. While I do not miss the oppresive heat, I am getting excited to head back to SC in a few weeks.
I apologize that there are no new and pretty figures to show, creating a workable model has taken more time and finesse than I had originally anticipated.
I finished creating reciever functions for the Ryukyu arc stations last week. I ended up with eight in the end because one of the last stations I was working on was shut down in 2004 and therefore didnt have enough events to make a good receiver function. I started playing around with the forward modeling code last week as well. To do this we make a model file that looks something like this:
# Layers: crust, anisotropic wedge, isotropic half-space.
#thick rho alph beta iso %P %S tr pl st di
40000 3200 7200 4100 1 0 0 0 0 0 0
20000 2550 5500 3200 0 9 9 0 0 0 25
30000 3000 7000 3950 1 0 0 0 0 0 0
0 3300 8200 4700 1 0 0 0 0 0 0
This is just a sample but the idea is to create a model of the layers in the subduction zone with the correct thickness, velocities, aniosotropy, strike, dip ect so that the synthetic receiver function created from the model has the same major features as the one that was made from the data. The model above gives you a receiver function that looks like...
As you can see it would be impossible to match every feature you see with this model but the idea is the replicate the major ones.
I have also been writing my first GMT script this week. Starting it was a bit of a struggle but Rob's tutorial and the one online were very helpful. And of course Erin helped me work out some of the kinks once it was up and running Just finished this guy a few hours ago (still slightly shocked that everything did what it was suppose to)
This is the lovely Ryukyu Arc in southern Japan. The red triangles are all of the stations. The contour lines are slab depth. The solid black line is 6km depth and the dashed ones are 50km, 100km ect.
Finally wandered into the Peabody museum yesterday (my parents were in town). It is pretty amazing the variety of what they have there. Also, we have our last softball game today. wish us luck!
Still alive for those of you who were concerned It has been a crazy first three weeks here in New Haven but so far so good. The plan as of now is for me to create receiver functions for nine seismic stations along the Ryukyu Arc (in SW Japan) and then do some forward modeling to try and locate anisotropic layers in the subduction zone. Specifically we are looking for evidence of serpentinization in the upper mantle of the subduction zone. So far I have completed five receiver functions and have gotten quite the hang of it while becoming comfortable using unix and SAC. Erin, the grad student I am working with, has been incredibly helpful especially as I was struggling through the first few stations. I will be using GMT later and am hoping it wont send me through too many bottles of advil...
this is one of my first reciever functions. the vertical axis is back azimuth and the horizontal axis is time (in sec) from the first P wave arrival. The left box is the radial component an the right box is the transverse component. red indicates a transition from slow to fast while blue indicates a region of fast to slow.
On a less academic note, I have unofficial joined the geology departments softball team. we play a game once a week against one of the other science departments (last week was neuroscience I believe). We are not very good but there is a grill and beer involved so no one is terribly upset that we have yet to win a game.
While it has rained quite a bit I have to say I am grateful for a break from the southern heat. and as for the obligatory workspace picture (I am pleased to annouce that I am no longer homeless)...
there you have it. over andddd out.
Arrived in New Haven, CT sunday night after 15+ hours in the car (thank goodness for audiobooks!). Although the traffic is almost as bad as I feared, my apartment is practically next door to the geology building. While my advisor is away this week I did have the luxury of meeting her on monday, and like I am sure most of the interns have found, I had no reason to be nervous. I have a better idea of what my project entails after meeting with Dr. Long. I am going to be using a technique called reciever function analysis to study seismic anisotropy in the upper mantle beneath the Ryukyu arc in southern Japan. Lucky for me, Erin (one of Dr. Long's grad students), has been using this same technique to study to the subduction zone on the northern island of Japan and has even written a handy dandy manual for the SAC program I will be using to analyze the data. I owe her at least a lunch or two for this.
As for the rest of the week, I still need to explore the rest of campus (what little I have seen is beautiful) and finish reading the stack of scientific papers ("um, is that english??") sitting on my desk. Speaking of desks, I am techniqually "homeless" at the moment as far as a work space goes. The nice lady in the main office may or may not have laughed at us when Maureen (Dr. Long) inquired about free space. So for now I am crashing in the office of my roommate Laura, who is studying paleo-botany? (something to do with very old plants). However it seems that her real passion is dinosaurs... and she is in good company. Apparently I have landed in the paleontology center of the northeast...complete with dinosaur skeletons hanging from the ceiling.
Changing gears to food (priorities people)...when it came time for lunch on the first day, I followed the group of grad students to what looked like a tiny fair in one the campus parking lots where I found among the trolleys and carts advertising burritos and burgers not one, but four, Thai food places! needless to say I will be sampling them all more than once over the next ten weeks In the name of science of course...
Still digesting all the information we have been given this week. This has been a great starting point for the summer and I cannot wait to get going on the internship. Since I have never been involved in a formal research project before this summer the first few weeks will likely consist mostly of getting my feet wet and making friends with the computer programs (and hopefully a few people). My biggest goal for the next few weeks is to not lost or overwhelmed with all of the material/data and to lay out a fairly detailed plan of attack for the rest of the summer. wish me luck