archive-edu.com » EDU » I » IRIS.EDU

Total: 1070

Choose link from "Titles, links and description words view":

Or switch to "Titles and links view".
  • IRIS Internship Program - Eva Golos
    good coverage and if I get bored during the fall I have something to do Last weekend my parents and my brother came to visit me which was fun It s been horrendously hot in Wisconsin so they enjoyed getting out to dry moderate California We passed the time in the traditional Golos Family Vacation Style which is to say spending every waking moment driving eating hiking walking or otherwise frantically trying to take in all the sights of the Bay Area In three days we managed to cover Berkeley downtown San Francisco Año Nuevo State Park again for me though we got to see elephant seals this time Butano State Park Santa Cruz Sonoma as well as the Stanford campus It was exhausting but really fun to more parts of the region and to hang out with my family since I ve only spent a week at home since January Because most of my week at work was spent picking I don t have many images that will look too different than what I ve posted here already Simon warned me earlier this week about getting lost in my event picking and losing sight of the bigger picture of the project I could definitely see that beginning to happen so I ve on and off been tinkering with a GMT script from a grad student that will plot the splitting parameters for each station on a map It s hard to change my focus though when I ve been in the Picking Zone all day and I just want to get through as many stations as possible My general approach to working has always been to just grit my teeth and slog through even if especially if it s a tedious task So I guess this is another example of how doing research can be really challenging in subtler ways than the usual coding problem I have to learn to be flexible in terms of how I prioritize my tasks and learn to be able to switch mindsets quickly Fortunately I should be wrapping up my picking today and next week will begin the fun stuff trying to actually connect my SplitLab results to the anisotropy structure beneath the Ruby Mountains I m excited and a little apprehensive for this part I chose this project because I wanted to see how to make this connection between seismic data and actual geology So in a way these last few weeks are a test to see if this is really the sort of work I want to do in grad school And more immediately it s also a test of my SplitLab skills I ve spent nearly two months learning and using the program so hopefully my data will yield some sort of meaningful result Link to Post Comment on this Post 0 Comments Baby got backazimuth July 20th 2012 This week I ve been steadily chugging along picking events in SplitLab I ve finally finished the A stations which run down the central part of the Ruby Mountains It s pretty mind numbing work to be honest but I ve been listening to lots of NPR podcasts and a Bill Bryson audiobook which help Now I m working on the D stations which are scattered around the periphery of the area and were operating for only a few months so they should go quickly I only set aside one more week for picking so with only about one third of the stations done I ll have to chose a representative sample of the remaining stations in order to get good coverage So I m noticing a problem in terms of the locations of useable events In order to see the SKS phase I can only use events with a magnitude of greater than 5 5 and a distance of 90 130 from my stations Unfortunately the vast majority of earthquakes fitting these criteria are located near Indonesia and sometimes Papua New Guinea So I ve got really great coverage at a backazimuth of around 270 but virtually nothing between 0 and 180 In fact only one station A14 has a somewhat relevant point from this direction This image isn t the most intuitive so I ll take a moment to explain it it took me a while to fully understand all of it It s centered at the station with each small blue line representing one of the points I have picked Each event is plotted according to its backazimuth and distance to the station while the angle of each line from 0 represents the fast axis splitting direction The length of the line is proportional to t the time difference between fast and slow axes Red circles represent null events in which backazimuth is either parallel or perpendicular to the fast axis This particular station was exciting because it can be seen that there is a point with a backazimuth in this shadow area where I haven t gotten many points 139 54 to be exact It s not necessarily a very good data point notice how much larger the splitting time is than for the other points which makes me suspicious but it s reassuring that it appears to be yielding a splitting direction similar to the other points Last Saturday I went with some other interns from various Stanford programs to Hollister California which is about an hour or so south of Palo Alto It s near the area where the San Andreas Fault splinters a bit with the main portion of the SAF stepping to the West and the Calaveras Fault and later the overdue to rupture Hayward Fault splitting off to the East it is between these 2 systems that the San Francisco Bay lies Anyway Hollister lies directly above the Calaveras which is currently slowly and steadily creeping This is in contrast to the stick slip model of motion which is associated with strain buildup and sudden earthquakes So Hollister doesn t experience large earthquakes but everywhere there is evidence of the fault slowly chugging along Here a cracked curb clearly shows the right lateral motion of the plate And here a sidewalk and concrete fence are in constant need of repair It s a small price to pay when you consider that Hollister residents don t live in fear of another large earthquake like many Californians And finally we stopped at the mission at San Juan Bautista on our way back into town I learned that El Camino Real a major road that goes along the Peninsula which I live a block away from was originally the name of the road connecting the Spanish missions in California spanning almost the entire state Link to Post Comment on this Post 1 Comments Halfway There July 13th 2012 So last weekend marked the official halfway point of my internship I realized I never really acknowledged that in my blog post last week though I did speak with Simon and Mairi to outline a more definite timeline for the rest of my time in Palo Alto So in honor of this occasion I ll spend some time looking over the goals I set in the beginning of June 1 Improve knowledge of seismic methodry how sensors work how data is collected and interpreted I got to work with the sensors and the data acquisition a little bit when we were out in Nevada I can t pretend that I understand all the electrical complexities of the equipment but I know the basic components of the stations and I can now download data from the SOD database 2 Gain facility with seismic data interpretation and the necessary software related improve computing skills especially in UNIX and programs like GMT I m definitely waaayy better with SplitLab now I ve written a few scripts in UNIX and though I don t use Matlab too much outside of SplitLab I ve brushed up my skills just by helping some of the other interns with their codes 3 Learn to connect seismic data to real features in particular to relate anisotropy to physical structures Haven t done much with regards to this area but I m planning to spend a lot more time focusing on the geological interpretation during August 4 Talk with professors and grad students and become more comfortable interacting with people in an academic professional environment I ve gone to a few events and I met a lot of people when I first arrived However I ve noticed that once I settle into a new workplace and get to know the people immediately around me I m not that good at branching out and meeting other people So I m still going to work on this one 5 Construct a plan for after graduation next year This part might involve researching grad schools and or taking the GRE even if it seems intimidating right now Well I signed up for the GRE and spent a little time last weekend looking at some potential schools advisors This is something I can continue to chip away at over the next month 6 Enjoy spending the summer at Stanford I ve never spent more than a week or two at a time on the West Coast and I want to get the full California experience Some things I want to try surfing In N Out Burger and buying cooking lots of local products From biking around I ve gotten pretty familiar with Palo Alto and with Stanford a nontrivial task considering how huge the campus is I haven t been surfing but I did go boogie boarding and I did have In N Out Burger I approve There s a nice farmer s market on California Avenue very close to my apartment that I checked out last weekend I m planning on getting produce from there more since Trader Joe s though overall a wonderful place has less of a fresh produce selection than I d expected So that s a pretty good summary of both how my summer has gone and what I can expect for the next month This week my work has gone slower than I d hoped The UNIX code that I ve been using to rename and sort my data files to make them more SplitLab friendly was giving me a lot of problems on Monday Alex the other intern in my lab who is using SplitLab showed me how to re order the data so that I didn t have to do any re formatting He also showed me how to make sure the components were all of the same time span which solved another problem I d been having So I ended up just re ordering all of my data When I finally started to go through the stations I realized I have way more events than anticipated sometimes over 300 per station I mentioned earlier that I d constructed a rough timeline Well in that I had assumed I could finish 2 stations per day it doesn t look like that s going to be possible unless I can improve my speed considerably Mairi told me not to worry that I could finish the work even after I return to New York in the fall thank goodness for ssh Y In addition one of the grad students tinkered with the SplitLab code to produce a nice colorful map of the anisotropy parameters This is so that we can stack all the results for a single station and hopefully reduce the error due to noise It was cool to see the process first hand of a student reading about a technique in a paper and deciding to implement it Plus it produces really cool looking images This weekend I m going on a field trip sponsored by the School of Earth Sciences to Hollister to see the San Andreas Fault There s a lot of slow slip faulting there and it should be interesting to see firsthand I ll post pictures next week Link to Post Comment on this Post 0 Comments Holiday weeks and fake earthquakes July 6th 2012 This week has gone past so quickly mostly because it s been so fragmented due to the 4th of July It was pretty nice having a mid week break especially one so filled with sun and good food and it s like there have been two two day weeks It also means that I didn t get quite as much done this week as I normally would Some friends of mine from school came out to visit me last weekend and it was really fun to catch up with them and show them around the area This story isn t completely unrelated to seismology because we visited San Francisco where we saw a really good exhibit on earthquakes at the Academy of Sciences in Golden Gate Park There was a simulation house that imitated the Loma Prieta 1989 quake as well as the San Francisco earthquake in 1906 Never having experienced a real earthquake I can t really comment on how accurate the simulation was they did tell us that there wasn t any vertical motion but I m pretty sure that I felt some Love waves Later we saw a planetarium show that we d thought would be about the sun but it turned out that it was also about earthquakes Not much information was new to me but it was entertaining and they had some very good digital models of fault planes and seismic energy radiating outward In terms of my research I ve been picking events from the four Transportable Array TA stations located nearby our own network It took me a full day to finish the first one about 180 events however I got faster as I went on and finished the later ones more quickly Mairi has finally deemed me ready to begin processing our Ruby data in earnest so I ve been downloading two years of data for 50 stations It s a huge amount of data the code has been running for almost two full workdays Currently it s giving me some trouble so hopefully I won t have to restart it completely When that finishes I ll finally be able to really dive into the bulk of my analysis Hope everyone had a good holiday week For those of you affected by all the crazy weather in the Eastern States hope that you re coping and doing all right Link to Post Comment on this Post 0 Comments Mystery Pulses June 29th 2012 One of the most frustrating things I ve had to accept has been that not all of my data will be useable In fact well over half of my data are most likely not going to yield useful results either SplitLab produces an error or the SKS wave signal isn t distinct enough or the phase has traveled from a null direction perpendicular or parallel to the fast axis of propagation or the seismogram is obscured by noise or Basically there can be any number of reasons that a seismogram is bad And as someone who as a matter of principle doesn t like to waste evidence earlier this week I accidentally left a jar of marinara sauce out all day and it went bad but I waited several more days before actually throwing it out because I felt bad about not finishing it it can be difficult to just skip over a seismogram However I ve had to learn to recognize when one isn t going to give me a good measurement right away because otherwise I m just going to spend a long time trying various time frames and filters and never going to gain anything meaningful Example Alex another undergrad intern who is using the same methodry I am but for a different area and I have both noticed that seismograms sometimes show what I like to call Mystery Pulses wave packets that occur periodically but at different times on each component such that they block out any other sort of signal also guys I m really proud of my arrows and text box on this picture Whenever I see these pulses I know that there s no way I m going to get a useable result Sometimes I don t even realize that they re present until I change the filter zoom out and recognize with a small quiver of horror the unpleasantly familiar oscillations of these infernal Mystery Pulses of Doom Not wholly unrelated anyone else realize that they ve become far too emotionally invested in some squiggles on a computer screen Link to Post Comment on this Post 2 Comments Field work a photodump and some SplitLab And more field work June 22nd 2012 Another week done I can t believe that it s been almost a month since the orientation constantly moving around and going out to the field have really messed up my perception of time This coming Monday I ll finally be able to move into the room that I m renting and I m not going to lie I m super excited to spend more than a week at a time in one location This nomadic lifestyle I ve been leading is exhausting Last weekend we finished up taking down all the seismic stations in Nevada We got to do a little bit of additional hiking around in the Rubies and it was nice to get a chance to climb around on some rocks As promised here are some pictures from the trip One of the seismic stations Struggling with a barbed wire fence I m not going to be disappointed if many years pass between now and the next time I encounter barbed wire And the middle seat of a pickup truck cab This is Angel Lake in the highly metamorphosed northern side of the Ruby Mountains For my fellow rock

    Original URL path: http://www.iris.edu/hq/internship/blogs/user/53 (2015-11-11)
    Open archived version from archive

  • IRIS Internship Program - Dulcie Head
    figures for this post I just finished re processing my data because we found that cutting the traces to try to isolate the surface waves and then selecting more periods to try to get dispersion values for gave better results I am much more efficient at processing it now Hopefully this will be the last time I process it and then we will just look at the results for analysis and conclusions Right now I do have comparisons to the PREM but not to the results from Yoshizawa so finding and plotting those dispersion results on my figures is the next step for analysis I now have all the results I need to set up the tomography and once I can perform the tomography inversion on my data then I can compare it to Yoshizawa s results in that form as well So after I add the Yoshizawa dispersion results to my figures if that is possible then I will perform the checkerboard test to see the expected resolution for the tomography using my paths and then actually do the tomography I m excited about my progress In other news I went to the Old Bus Depot Markets last weekend which I really enjoyed I ate a nice cinnamon pear danish and bought some vegetables I m hoping to go to either the Zoo and Aquarium or the Cockington Green gardens this weekend Exploring Canberra is fun and there is no shortage of places to visit here Till next time Link to Post Comment on this Post 3 Comments Week 9 The Trouble with Time August 3rd 2012 July 30 to August 3 It s getting closer to the end here and very close to the abstract submission deadline I m currently on my second draft of the abstract and I m going to process my data and try to get that tomography code working before the final draft and submission I just joined AGU yesterday so I ll have to wait a couple more days before registering for the meeting I m quite excited to go Hopefully in my last week here I ll spend some time learning Illustrator so I can make or at least start on my poster If I can t finish the poster here I ll need to think about how to transfer the necessary figures to my laptop before going I m going to miss everyone here and I ve made some good friends but I m also very excited to be heading home and then back to school I plan to submit my abstract to the Seismology General Contributions session and request a poster so I ll need to make sure everything for my AGU registration is working on Monday For now I m trying to see if there is a way I can cut or filter the data differently in order to extract more results Today was a very unproductive day which is always disappointing but I have high hopes for next week There were many interruptions today because they were rearranging the room where I work there was a going away party at tea in the morning for the director of RSES I had a meeting and there was an hour of lecture and an hour of tutorial for my adviser s Physics of the Earth class Also my Ethernet cable went missing somewhere in the process of them moving everybody s desks around so I need to get that back Thrilling stuff I know Even though today was fairly underproductive I think this week was actually fairly successful overall and I now know which data I can use and how to use it and all the processing and plotting codes are working I m just going to try to improve the results next week and get the tomography code working If I can do that by Tuesday then I think I ll be in really good shape for submitting the abstract its fine now but I d really like to be able to add some real results instead of just aims and hopes On the home front I made banana bread twice And forgot to take a picture both times sorry Here s a cool one of one of the animatronics at the dinosaur museum instead though No particular plans for this weekend yet but hopefully next week s blog will have some exciting pictures of wherever we go And also some good and maybe finalized figures I m looking forward to my last three weeks here I know it s going to go by quickly Perhaps too quickly for all the work I want to get done but in some ways not quickly enough because I m really feeling ready to go home I think that s always the trouble with time though It always goes too fast and not fast enough all at once I m sure Cheers Link to Post Comment on this Post 0 Comments Goals Version Eight July 31st 2012 While I haven t done an actual analysis yet it is now possible I m very excited about my new figures Here is the eighth update of the goal list crazy how time flies Use surface wave group velocity dispersion for tomography to investigate the subsurface in Australia o Use the good data for tomography to make a crude map of the velocity structure in Australia Learn the tomography code I ve started work on this and I think I m making good progress so far I m working with examples and following through the instructions UNIX o Learn about Illustrator o Add comments Understand what group velocity dispersion is used for and be able to communicate knowledgably about it o Read papers and thesis from someone at ANU concerning group velocity dispersion Be able to produce a poster which describes my project that is up to professional standards for AGU o Select the good data from the new figures o Register for AGU o Submit abstract to AGU Maintain this blog about what I have accomplished and my goals Explore Canberra o Go to the National Zoo and Aquarium o Go to the Old Bus Depot Markets Here is one of my new figures I m pleased with them Now I just need to run the code for all my data and look at all the outputs I m just waiting on my adviser to see if the layout is ok and if there s anything else we want to add to the plots before printing them After they re all printed we ll sit down with them and go through and only keep the ones with visibly good data Then it will be time to use the tomography code to invert the travel times and make my first map I m really hoping to do this before August 8th when we will submit the abstract for AGU We went to the National Dinosaur Museum on Saturday It was really fun there were fossils sculptures replica skeletons and animatronics His teeth were actually pretty sharp Link to Post Comment on this Post 0 Comments Week 8 Kangaroos and Dinosaurs July 27th 2012 July 23 to July 27 Well hello again all the time seems to just slip by That AGU abstract deadline is just around the corner I hope I actually have some results by then Work is going well here and I feel very productive most days I recently discovered that for some of my data there was another smaller event recorded near the end of the time that I was investigating for some of the stations but it shouldn t take too long to go back at cut the traces a little shorter By the end of Monday I hope to have produced the new figures of the data so we can go through and pick what is good enough to keep and what has to go Then after we ve selected the good data we can invert for velocity structure and create the first rough tomography map I m very excited about this and the progress I ve been making I feel that the project is chugging along I ll share some images of the data on Tuesday and that s about it for this week In unrelated news I ve been practicing making my own bread It s a good wayt to spend some time and I enjoy it This is my third loaf This one has a much nicer shape than the first two because I actually bought a loaf pan I plan on making some banana bread soon as well if it turns out well I might even post a picture I m very spoiled at home and in my dorm in California where I have lots of cooking tools and pans and ingredients stocked up but I m very pleased with my new loaf pan and there s a muffin tin at the house here so I m slowly expanding my baking enterprises This weekend I will go and see the National Dinosaur Museum with Marija and Archana we will miss Debjani though because she left early this morning Hopefully there will be some cool pictures of the dinosaurs for next week s post apparently there are skeletons sculptures and animatronics I m very excited Last weekend we went on a good adventure to see some kangaroos and took some great photos Here is one that Debjani took Cheers Link to Post Comment on this Post 0 Comments Goals Week Seven July 24th 2012 I m finally closing in on some figures that we might be able to analyze and get some interpretations and results Use surface wave group velocity dispersion for tomography to investigate the subsurface in Australia o Go through the data and see what is good enough to use sadly I think a large portion of the data will be rejected o Use the good data for tomography to make a crude map of the velocity structure in Australia UNIX o Learn about Illustrator o Comment o Learn the tomography code GMT o Make new figures for analyzing whether the data is good enough to be used New figures will include A map showing the path between the event and the station The dispersion for that path The raw seismogram from that path A filtered version of that seismogram The earthquake information magnitude location date CPiS o Learn about sacmat96 so I can add useful commentary to the code o Learn how to make a dispersion curve for the PREM model SAC o Make a nice bandpass filter to show the filtered seismogram Understand what group velocity dispersion is used for and be able to communicate knowledgably about it o Read papers and thesis from someone at ANU concerning group velocity dispersion Be able to produce a poster which describes my project that is up to professional standards for AGU o Select the good data from the new figures o Find a meaningful way to arrange the figures for the poster Maintain this blog about what I have accomplished and my goals Explore Canberra o I don t think I ll be taking and more weekend trips while I m here but there seems to be quite a bit to do here in Canberra o Go see the National Dinosaur Museum and other attractions in Gold Creek Village o Go to the National Zoo and Aquarium o Go to the Old Bus Depot Markets Link to Post Comment on this Post 0 Comments Week 7 Five Cake Fridays to Go July 19th 2012 July 16 to July 20 On Wednesday at tea one of my friends asked me how long I had left here and I said 5 and half weeks to which he responded Good Six more Cake Fridays I think that s a good way to summarize how I feel about my time left here it s short but there s a lot left to look forward to There s also a lot left to do I ll be both happy to go home and sad to leave but right now my main worry is not accomplishing enough before I go Today was a good Cake Friday a nice chocolate cake topped with Smarties they re like m ms we have them in Canada but in the States you can usually only find them in the foreign foods section So now I have only five Cake Fridays left In my work right now I have processed the data from my six events and I have all the dispersion curves from that ones for each station and ones showing all the stations I updated the codes to plot the two different filters on the same page for each separate station and to have different colors and a legend for all the stations together I m learning a lot about GMT and soon I hope to post a map that has all my events and lines connecting to all the stations where data was gathered I probably don t have enough data to do tomography and make a map but we ll see I still need to find out if the way I m processing the data is appropriate though and I m assuming I m going to have to change some things in the code before I can really produce any final pictures The next big thing for me to do is to find or make the dispersion curves for the PREM model and add those to my plots It will be good to have something to compare my data to I think I may also add plots of the seismograms to the individual dispersion curves so I can see which curves we can clearly see the surface waves and which ones look mostly like noise I ve been catching up on reading people s blogs it s good to finally catch up a bit on what people are working on and see that frustrations with coding are not uncommon Fortunately for the most part I find the coding to be more interesting than frustrating even when it isn t working I definitely surprised myself with how much I like it Here are some of my plots for the March 23 2012 event On a side note it s my mom s birthday today Happy Birthday Mom Cheers Link to Post Comment on this Post 2 Comments Goals 6 0 July 19th 2012 I actually can t believe that I m more than half way done now I had to count the days to double check The time has flown by so far and I think it s only going to go faster Here s the updated goals list Use surface wave group velocity dispersion for tomography to investigate the subsurface in Australia o Create all the dispersion curves for all six events o Figure out if the differentiation step in the code is appropriate for my data UNIX o Learn about Illustrator o Comment my codes I want them to be comprehensible to other people and to myself in six months when I ve forgotten all the specifics GMT o I ve been doing a lot of GMT practice recently making my dispersion curve figures I do have a GMT helper code and I should add more information to that CPiS o Learn about sacmat96 so I can add useful commentary to the code SAC o Comment in the code what SAC is doing and how we use it Understand what group velocity dispersion is used for and be able to communicate knowledgably about it o Read papers and thesis from someone at ANU concerning group velocity dispersion Be able to produce a poster which describes my project that is up to professional standards for AGU o Find PREM model to compare my dispersion curves to o Find other maps to compare my data to o Find a nice way to arrange all my figures so they can be interpreted in a meaningful way Maintain this blog about what I have accomplished and my goals o Get back on schedule with blog posts almost there Explore Australia o Consider going to Melbourne for a weekend Link to Post Comment on this Post 0 Comments Week 6 Where did it go July 17th 2012 July 9 to July 13 I somehow barely noticed that week going by I got back Monday night the 9th from Sydney and my brother was still here with me for another week So between a 4 day work week and having my brother around the week just went by so fast In fact it went so fast that the homework deadline really snuck up on me Fortunately I keep a master to do list on my computer so I didn t forget entirely I kept meaning to work on the homework while I was at work and then forgetting because there was more code and debugging to do I spent some time modifying the big code so that the naming conventions and variables are more suited to my data It was written for ambient noise data and I m using earthquake data so there were quite a few changes to make Everything seems to be up and running now the next step is modifying my scripts that make images of the dispersion curves so they are nicer images and possibly include the calculated dispersion for the PREM or other models The dispersion curves will be most useful if we can also compare them to dispersions that other people creating maps of Australia computed My adviser is working on getting those maps and dispersion curves for us The time in Sydney was wonderful and I m going to miss having my brother here I can t believe I have less than six weeks left it s weird how fast the time has gone already and it s only going to get faster I hope I have something to write an abstract about soon I do have lots of figures now though Here is a map of an event I use and the stations that I took data from The event occurred on March 23 2012 and was magnitude 5 7 You can see a place where there are a lot of stations all in a small area I think looking at those curves could provide a good estimate for error or at least some sort of maximum difference calculation Here are some of the dispersion curves from that event This is the curve from QLP one of the stations closer to the event And this is a plot of the dispersion curves from all the stations that I gathered data from I think I d also like to look at dispersion as a function of azimuth if there is time Hopefully next week I ll have some more figures to post especially these figures with the PREM model dispersion curve added One other thing I do need to do more is read everyone else s blogs and send some post cards I stocked up on postcards in Sydney now I just need to write them and get some stamps Till next time Link to Post Comment on this Post 0 Comments Goals The Fifth July 14th 2012 I m running late on my blog posts the trip to Sydney kind of threw everything off for a bit but I m slowly getting back to my usual schedule This week was short but fairly productive Use surface wave group velocity dispersion for tomography to investigate the subsurface in Australia o So far I have gathered data from six earthquakes magnitude five and above that occurred on the land in Australia o I need to go through that data and create the dispersion curves maps of the event and seismometers hopefully adding lines between the event and each of the seismometers and then see what the next steps are UNIX o I finished two different codes to plot the seismograms one that plots each one separately and one that plots them all on the same plot in different colors o I want to learn how to make those figures nicer adding legends and making a nice layout for all the separate ones o Keep learning about the codes I m using avoid the black box o Comment the codes I use frequently GMT o I would like to update the code I have that plots the earthquake and the seismometers used to create dispersion curves so that it plots the great circle path between the earthquake and each of the seismometers I would also like it to automatically adjust the window of the graph to include all stations I used CPiS o One of the codes I use calls sacmat96 and I would like to know what that program actually does SAC o I don t have any specific goals concerning SAC now but I would like to keep learning about it Understand what group velocity dispersion is used for and be able to communicate knowledgably about it o Read papers and thesis from someone at ANU concerning the group velocity dispersion Be able to produce a poster which describes my project that is up to professional standards for AGU o Make the dispersion curves for all six events then start contemplating the abstract o Find PREM model to compare my dispersion curves to o Find other maps to compare my data to Maintain this blog about what I have accomplished and my goals o Get back on schedule with blog posts o Include more figures from my work Explore Australia o Consider going to Melbourne for a weekend Link to Post Comment on this Post 0 Comments Week 5 To Sydney July 10th 2012 July 2 to July 6 This past week was a successful and short one I felt really good about my progress because I got the big code to work The big code is how I think of the code Mallory gave me that creates the dispersion curves There is still quite a bit to do with the code because I need to tailor it to give useful results for what I m working on but it now does exactly what it was written to do with no errors on my computer which was a major accomplishment So now I m at a place in my research where I might be able to write a more complete and accurate project description which is exciting Stay tuned for that The final output of the big code for this week was two different dispersion curves one not using the phase matched filter and one using the phase matched filter These dispersion curves aren t particularly helpful right now because they are an average of all the stations response from one event I m now going to work on making figures that have all the dispersion curves on them without averaging I concluded this week by giving a short presentation to the group I work with The group now includes three PhD students and three other interns it has grown since I arrived We had another PhD student Maria and another intern Jerry arrive this week Maria is from Croatia and Jerry goes to Princeton I m looking forward to getting to know them better I really like working in this group everyone is very friendly and helpful I missed the webinar because it occurred at 4am my time while I was in Sydney I tried to wake up but it didn t go so well I m looking forward to seeing it though and catching up on that homework My brother and I spent Thursday night to Monday night in Sydney and we had a great time That s why this post is late as well We went to the aquarium the wax museum the wildlife park and the Sydney tower We walked across the bridge and went to the Opera house and the Royal Botanical Gardens Here s the part where I make up for not having enough pictures in my other blogs Till next time I hope everyone is having as great a summer winter as I am Link to Post Comment on this Post 0 Comments Goals Number Four July 3rd 2012 I always find it a little disconcerting to update this file once a week because everything changes so much in a week But that s definitely a good problem to have Develop a specific project and write a set of goals for that project o Use surface wave group velocity dispersion for tomography to investigate the subsurface in Australia o The dispersion allows us to look deeper than just the crust hopefully get good data for longer wavelengths so we can have resolution at larger depths o Find data from recent past couple of years large greater than M 5 0 earthquakes o Use the data to create dispersion curves o Use the dispersion curves to do tomography o Compare tomography from my results to other maps of Australia This will be interesting because most tomography in Australia is done using data from earthquakes that occur around Australia but not actually on the continent UNIX o I have quite a few new codes I m using to do the frequency time analysis that develops the dispersion curves I understand I think all of those scripts and what they re doing but they call other scripts which I don t understand In total I run four scripts which call nine other scripts two of which are written in FORTRAN and two CPiS programs Then I wrote three other scripts I use in conjunction one to prepare the data one to clean up and organize all the output files from the main scripts and one to hypothetically extract and plot the final dispersion curves That last one is what I m working on right now I just need to fiddle with GMT a bit more o I m learning a lot about UNIX and shell scripting my goals for now are keep working on my codes improving and writing new ones as is necessary and keep learning about the codes I m using avoid the black box o Comment When I started out I was so good about commenting every step That s not efficient but if I want to use this script in the future I will probably have forgotten everything about it and so I should spend some time closer to the end of this projecting commenting on scripts I use regularly I think that if I used it to make a figure for my poster at AGU I should have a script that is well documented and explained to back it up We ll see if I have time to meet that goal GMT o I made a nice code that follows on the code that prepares the data which reads the headers and extracts all the station names and locations and the event location and puts all that on a map So far it s not a smart code in that it doesn t figure out the region and the scale by itself but I have plans for that o I ve experimented with some code to plot seismograms and now I m going to put that to use in making dispersion curves More news and hopefully images from this soon o I m really excited to finally be making some figure that actually might mean something Still a long way to go but it looks like I have a project that I can make some good progress on now and I m feeling very optimistic about this CPiS o The scripts that Mallory gave me call several different CPiS programs and use SAC I m glad I spent time learning both those programs For now I don t have any new specific goals regarding CPiS other than attempt to understand exactly what they re doing when I use them in other scripts SAC o The code that prepares the data does most of the work in SAC changing the headers and updating the origin time I mostly understand what the code Mallory gave me uses SAC to do and my goal for that is fully understand those parts of that code o I don t really do any data filtering myself it s all integrated into the CPiS programs so I d like to learn more about that too Understand what group velocity dispersion is used for and be able to communicate knowledgably about it o I have some papers and a thesis to read about this topic and its uses in tomography so I m looking forward to being more informed about that Hopefully soon I ll have some more specific questions and better ideas for exactly what I ll be working on and looking for Be able to produce a poster which describes my project that is up to professional standards for AGU o Once I have some figures I can start thinking about writing an abstract That deadline for AGU is definitely going to sneak up really fast o I m making an informal presentation to my group on Thursday about what I have been and will be working on This will be helpful for defining what I hope to accomplish and getting an outline of what I m working on I think this will help with abstract writing and general clarity about my project for myself and my peers Maintain this blog about what I have accomplished and my goals o Keep posting goals on Tuesdays and general blog on Fridays Keep including pictures Start including pictures from my work Explore Australia o My brother and I will be in Sydney from Thursday to Monday so that will be nice I m looking forward to having lots of pictures Link to Post Comment on this Post 1 Comments Week 4 Cake Friday June 29th 2012 June 25 to June 29 This week I made some good progress I now have a code that prepares all the data from the seed file so that all the SAC headers are updated and the origin is the earthquake time and all the traces are the same length Mallory a PhD student here gave me a code that extracts the group velocity curves It mainly uses a frequency time analysis which has multiple filters to determine the arrival times and group velocities at a variety of periods The code I was given requires many steps and many other codes and programs to run so I first spent time going through it and getting it to work for some of Mallory s data on my machine This took quite a while because all the different file paths and other programs called by the script had to be set up or modified It was also written in bash and I had been learning about writing in tcsh which isn t completely different but there were several new syntax things to learn too We did manage to get everything working for the original code and data on my computer Then the next task is to get it working for my data Fortunately the program I wrote for preparing the SAC files did everything we needed to do to prepare the data except for change the delta so there weren t quite so many data points That was an easy fix though and I felt really good that I d actually created a helpful script that did what we needed it to So my SAC files are ready for analysis but I need to change some things in her script because she was doing noise analysis and I m looking at earthquakes Most of what I ve had to change so far is file paths and naming conventions but I also need to make sure this is providing a helpful output That will be what I work on next week On a totally different topic one of the traditions here at RSES is teatime It s a great way to meet the other students and take a break The students also have a teatime tradition that every Friday is Cake Friday and someone brings cake for the group Most of the students here are gone right now taking a winter holiday or doing fieldwork or at a conference So it s a small tea group and it seemed that everyone had taken their turn to make cake recently so today it was my turn to make the cake I did not have any baking ingredients but I checked in the house and there was a muffin tin so I decided I would make muffins It was fun to bake Another really good thing about this is that it forced me to buy the basic ingredients for baking Cake Friday is fun I like the students here and I m grateful they re so friendly On other unrelated topics my brother arrives tomorrow and I m really looking forward to seeing him Also the campus looks really beautiful when it s foggy and cold in the mornings Link to Post Comment on this Post 3 Comments Goals Round Three June 26th 2012 Hello again I think this week the goals have changed quite a bit because I m making good progress on learning coding for all the programs Develop a specific project and write a set of goals for that project UNIX o I haven t made any progress with looking at the script that converts sac files to ascii files but I am making progress on UNIX and shell scripting in general o Dr Tkalcic gave me two of his scripts that take some sort of table input and make nice GMT plots I m currently working through these and learning a lot from them but I m still pretty far from being able to fully understand them o Every day I learn something new about writing code and I was especially pleased today and yesterday to get some for and while loops working I am also slowly learning about awk It s rewarding to see my codes become more efficient and effective GMT o I managed to create the code I wanted that converts the SEED file to SAC filez converts the SAC files to ASCII files reads the min and max values from that file and then sets those to the window for the plot and plots all the seismograms using psxy But after doing that I found out there wasn t much use for a bunch of separate images of raw data o So now my goal is to make a map of Australia that shows the location of the seismometers and the earthquake I m looking at and then create nice figures of the traces I m not yet sure what I have to do to the traces before I can make nice figures though CPiS o In order to use the CPiS program do mft which calculates the group velocity dispersion from a user defined fit I need the vertical radial and transverse components to be the same length with the same number of data points I need to prepare and filter the traces before I can actually calculate anything meaningful from them This is where SAC comes in o I also want to learn a new CPiS program sacmat96 because apparently it does the same thing as do mft but with automated picking instead of user defined so that should be more efficient and equally accurate SAC o I want to be able to use this program to filter and transform my data so that it can be used in CPiS and GMT o I have learned how to change all the headers so that the event time and

    Original URL path: http://www.iris.edu/hq/internship/blogs/user/54 (2015-11-11)
    Open archived version from archive

  • IRIS Internship Program - Ayla Heinze Fry
    up over the weekend to visit and travel around the rest of Alaska I went with them on the bus tours at Denali and flightseeing up to Mount McKinley It was amazing I got to see an amazing display of crevasses which is a significant portion of my project so it was great to see it in person When I get the histogram and my photos made downloaded then I ll post them up here Here s the histogram Link to Post Comment on this Post 0 Comments Week 7 Picks Picks and more Picks July 20th 2012 Well sadly I don t have much to show for the work I ve done over the past 1 5 2 weeks but I have been doing a lot I ve been making picks of icequakes for my second timeframe and although I felt like there were fewer icequakes my advisor showed me a histogram that was just representative of picks on 1 station and boy was I wrong Even when he produced the graph and I had an hour or hour and a half left of picks out of 5 hours I still had 3 times as many picks as I had in my last section It s been a very pick intensive last two weeks and I m almost at the point where I can locate all of them at once which goes much faster generally Only 9 minutes left of picking But for at least most of the rest of the day that s on hold because our system is being updated so I can t really get onto the computer Same thing happened with that histogram our system update was under way so I couldn t get a hold of it first I m in the library downstairs right now in order to write this So today I ll be working on catching up on some articles I ve been meaning to read and maybe starting to think about presentations and AGU abstracts and how to start those even if I can t do all of it yet Link to Post Comment on this Post 0 Comments The Midway point July 13th 2012 Well this week I officially reached my half way point for the internship half way through the week Last week I reflected on some of my goals from the beginning but now I m going to reevaluate them and determine what old goals to keep and new ones to go on the list So here are some things I ve got continue hiking and get out in the field maybe 1 more time continue to read more of the icequake literature to help me with my analysis that ll come up soon finish my second round of icequake picks 2 hours out of 5 down this week thus far and I still have today continue to use matlab as a tool this includes coming up with more good ways to compare my two time periods in a reasonable way presentation preparedness I m going to include my AGU abstract as well as the talk I m giving here during my last week in this section figure out what I m doing for my senior thesis Some old things on my list that I ve accomplished learn more about glaciers and seismology use matlab as a tool use time lapse photography for science field experience hiking getting to go to Alaska Learing how to live on my own not in a dorm Now for some of my progress from this past week I mentioned last time that I was going through and determining a new time period I ll did pick a period and have started my picks for that time and I ll show you how I got to that point But first I ll give you a couple of cool figures that helped wrap up my last time period Here s all five hours 6 29 11 29 UTC aka 10 29 pm 3 29 am AK time The fuschia colored icequakes should be easier to see now We then added some error ellipses which can give you a headache if you look at all of them at once As you can see below There are definitely some crazy ones I ll admit so that s why I m going back and looking at those events to try to see what in earth is going on But in the second figure below this one I ve chosen a shorter time period to look at so maybe we can actually understand the ellipses and their importance When we have a feature where the ellipses long axes are perpendicular to the feature we are more convinced that it could be an actual feature On the other hand if the long axes of the ellipses are in parallel with the feature it is harder to convince yourself that it is actually a feature and you might conclude that it is possible all of the points occurred at one location So if we look at the medium sized ellipses stacked on one another on the right side that linear alignment can actually be a feature On the other hand the tight cluster on the left where the ellipses line up with the feature we find it less convincing the nature of that feature Also we re starting to think about looking for patterns for automatic detection Below I ve just included some of the stacks which pulled out just some of the most common patterns and it tells you how many there are in that subgroup of similar waveforms These stacks are looking at individual stations On the left you have our station CNTR while on the right is station LINC To find my new time I started looking at the beginning of my first group and started looking at my precipitation temperature and wind for the week following We therefore have a consistent amount of influence from preciptation We have no precipitation during this time period Our next idea was to look for sunny periods in the middle of the day for contrast and preferably within a few days so we narrowed down the search further I calcualated some times that I would consider the middle of the day with the most sun cover I determined to look at a time between 11 am and 4 pm AK time 19 00 00 00 UTC The results narrowed down to a few days can be seen in the second set of graphs below It has a few times marked off by colors on each end of the time period The back markers represent our control period The other colors represent potential time perods Along the bottom of each graph the format is day hour I ended up looking at time lapse videos over eachof those time periods to determine which time period had the clearest sky The first one marked in magenta had very clear skies and therefore presents the best contrast to the control period I ve made lots of progress with my picking in this time period and will hopefully finish up the picks by mid week next week Until next time Let me know if you have questions Link to Post Comment on this Post 0 Comments Week 5 Tying up one end for now Part 2 emerges July 9th 2012 Since my last post was also a bit late you heard some about my last week as well I found better ways to look at some of my errors and interpret the points that don t seem to match I had record sections to look at arival times Most of what the second part of the week was doing was tying up my control group which I revised to be a full 5 hours I ve been going through my old picks with my criteria of having an event with distinguishable waveforms on 6 stations I ve been taking note of when these criteria were not used and I won t use them in my final analysis I ve also been filling in some gaps of time and am nearly finished I ve also been looking more closely for a new time to start picking My control period was in the middle of the night so when there is the least water delivery to the glacier there was not precipitation or recent precipitation it was cold so less melting influence from insolation Talking with my advisors we have decided to look at a time period that also did not have precipitation but was sunny and in the middle of the day and therefore having more water delivery due to melt To make comparisons I ll be doing picks for the same time duration 5 hours I ll be looking for a time within a couple of days of my first set I have glanced over some potential days but need to look at some of the photography and various other data to check for the best time I just went on my first trip to Denali It was lots of fun Really great weather in the first part of the day and then it downpoured on us later Also if any of you know the book movie Into the Wild they moved the bus that Chris McCandless lived in to outside of this brewery about 10 miles away from the Denali Park Entrance The original location of the bus and where Chris lived his final days was only about 15 miles away It was errie in a way and just makes you think Reflecting a bit now on some of the goals from my first post I ve learned some more linux but not as well as I d initially intended I ve been too busy doing other things not specific to linux aka matlab I can say I m getting better at having academic conversations between various social gatherings with grad students and the conference here I ve gotten some experience in the field and hopefully will get more And now I am confident about being able to do other field work that comes my way I ve gotten in some better shape to some extent though I m still not really used to biking everywhere I m more used to walking And I can say I ve been out enough that I ve enjoyed exploring some of the area I ve been enjoying daylight but I will be looking forward to nighttime And if I m lucky I ll get to see the aurora at the end of the summer if it gets dark enough Not much progress on next year or post graduation yet starting to think a little more about it now Check out last week s blog It s been updated with pictures Until Next time Link to Post Comment on this Post 1 Comments Week 4 Multitasking July 9th 2012 July 3rd 2012 Last week was filled with multitasking because there was a glacial geology meeting IGS right on campus so I was running back and forth between the geophysical institute and the conference trying to take advantage of the conference material people and experiences while it was here I met lots of cool people from all over the world and got to go explore out of Fairbanks once during the week I got to go to Chena Hot Springs which included going getting a tour of their geothermal plant the greenhouse where they grow some of the food they serve and the Ice Museum which is actually cooled by energy from the geothermal plant with energy from the hot spring I ll be sure to include photos soon I also made some more picks which can be seen below just about 5 hours worth of data now Definitely good groups and clusters See below Based on Katie s comment from last week I worked on code to find the events that seemed most out of norm I picked looking outside of the blue dashed lines with respect to time residuals The red points in the right most figure are the points that I would look into What I ve mostly concluded can be found in my second comment from last week s blog With help from the supportive community around me I was also able to make some record sections which for those who don t know what they are essentially plots along your axis relatively For example I was plotting my waveforms with actual time on the x axis and distance on the y axis I thought I was a lot closer for a while than I actually was so it took more time than expected Basically though if we were to plot a line along the moveout we would get the velocity at which the wave travels What doesn t fall on a line might be due to the composition or amount of air bubbles structure etc of the ice I also simply worked on some more ways to look at my data just in case it ll be useful in further research Now that I almost have a good control group goal spanning 6 hours I m starting to think more about my criteria for picks Before I charge ahead with everything else I have the following immediate goals Determine a set criteria for my picks e g at least 6 stations must show this signal clearly enough to pick Go back through my control group to make sure all of my events meet the set of criteria Find the best way to go through temperature data I m just now starting to look at and Pick a variety of other times I want to look at in order to determine meteorological influences i e picks times that are cooler and warmer and make further picks over those representative times In other words I ll be going over a more broad scope rather than just very nit picky small timeframes Also this past weekend I went out in the field with a glacial geology student to the alaska range Backpacking 10 miles up through 2 passes though snow glacial quicksand muck and rivers to reach the glacier getting to hike and drill holes on the glacier and moraine and backpacking back through everything It was my first backpacking trip ever second time on a glacier first time hiking on a glacier and my longest hike by the end of it It was definitely an amazing experience Photos to follow Also that s why this post is late Had short notice and needed to pack quickly when I d been planning on doing this Oops Until next time UPDATED July 9th 2012 A A Chena Hot Springs Geothermal operation B B Ice sculptures at the Ice Museum at Chena Hot Springs C C The actual hot springs D D My first backpacking trip top of our second pass E E Decent into the valley we stayed in F F The glacier of our field excursion G G Drilling into morraine and glacier later H H Checking out nearby crevasses Link to Post Comment on this Post 1 Comments Week Three Pulling things together round 1 June 25th 2012 The last week an a half have been really busy and I ve definitely been going through a large of what my project will be but on a smaller scale I ve started to locate my icequakes using a program called dbloc2 which I can then load into a Google Earth file to see how they all plot along the glacier We have assumed thus far that the icequakes are at the surface in other words most likely dealing with crevassing This display of icequakes will continue to show more interesting results as I make more picks but already I can tell that there clusterings around some particular areas and this is with just 3 hours worth of seismic data The image below is shows this three hour time period All of the white dots are icequake locations The labeled red points are seismic stations There is a definite clustering of events around station LINB and the beginning of one around COED I ve also put in a lot of time working on quality control As I was talking about last week I was working on doing quality control on my own picks to make sure I was being consistent Our location program also requires a velocity model which needed to be changed from what is used for regular earthquakes to what is needed for icequakes In order to check to see if all the programs were running correctly and if the velocity model seemed to have approximately the correct velocity assigned I made some graphs comparing residual times the actual time it took to get from source to station vs the calculated time I ve also worked at tweaking this graph to pull out different points of interest to check quality based on other parameters I ve done so for station and seismic instrument type latitude and distance from the icequake origin Some of the graphs can be seen below This figure shows that there are indeed some stations that seem to work better with the model and those that have more spread We can also see that there are definitely outliers Generally speaking though this graph shows us that our model works well with our actual findings we have a trend that follows actual calculated Figure on left red by distance from origin Lighter reds are closer to the origin Except for some outliers stations further from the origin appear to have some less scatter but this may be due to lesser amounts of data Figure on right blue by latitude Lower latitudes are in lighter color Higer latitudes seem to have less scatter generally except for the occasional outlier I have also been playing

    Original URL path: http://www.iris.edu/hq/internship/blogs/user/55 (2015-11-11)
    Open archived version from archive

  • IRIS Internship Program - Calvin Johnson
    to Mikes plot his was colorful and revealed some type of trend mines was a colorful with a bunch of black triangles and no trend the black triangles I didn t pick a SsPmp time arrival for that station in that data set because it wasn t clearly visible Therefore I had to go through all of the seismograms and pick re pick the SsPmp time arrivals We also had the chance to review a paper written by Gregory C Beroza on Slow Earthquakes In all and I encourage you all to read this paper it was conveying that slow slip events SSE episodic tremor and slip ETS tremor low frequency events LFE and very low frequencies VLF correlate with the occurrence of slow earthquakes The results gives the reader more of an understanding of how a slow slip event can only occur if you have tremor which me personally I don t believe but the author goes on to reveal that there is some deviation between the source of the tremor and slow slip events i e love waves tidal forcing weak faults etc and that even though the slow earthquakes occurred in a deep extension of major faults in this study they can possibly occur in more shallow depths in the near future It also point out that Slow Earthquakes usually occur in younger sediments But enough about that if you re interested in reading it just email me at Saro357 yahoo com otherwise I m going to continue to tell you all about my 2 weeks Lately everybody in the office have been busy but the week was a turn for the better I had the chance to go to an ice cream social then right after that I went to a club with Noor and Yi a lovable Chinese student I met up here named The Brick It was a great experience and I ve been trying a bunch new things up here for instance cooking more than I usually do and Oh yea FASTING Also my roommate Harmony adopted a puppy and he s the best puppy you can have Here s a picture of him and also of some of my work Well that s all for this week Oh I almost forgot Mike was successfully able to permit an EarthScope Transportable Array site on the edge of Miami s campus They have already constructed an underground vault at this site they just need to install the equipment this tomorrow and I ll be involved in this epic event I m so excited I hope you all enjoyed my blog God bless and let me know if you have any questions Sincerely Calvin E Johnson Link to Post Comment on this Post 2 Comments The Seis of your Ambition Matters the Most June 9th 2012 Hi World Sorry it took me sooo long to get back with you all but I ve been through a lot these past 4 weeks Ok so where should

    Original URL path: http://www.iris.edu/hq/internship/blogs/user/56 (2015-11-11)
    Open archived version from archive

  • IRIS Internship Program - David Krzesni
    interested in geophysical research but I ve also started thinking that I might really enjoy sharing my passion in other ways I m going to talk with someone about a M S Ed program focused on Outdoor and Environmental Education next week That s all I can think of for now I m still having a great time in Ithaca Link to Post Comment on this Post 1 Comments Half way through June 29th 2012 This week I have been locating earthquakes I m continuing to get through about a month of data per week and there continues to be a lot of signal left to pick through The summer is going by really quickly I have to go back to New Mexico August 15 so I think I am about half way through my time here This is the first summer since I ve been in school that I haven t been taking summer classes It s been interesting to be doing something that seems much more like a job than school I think when you re busy with classes short term goals and deadlines it is easy to lose perspective of where you are headed in life Since I ve been at my internship I have been almost constantly thinking about where I am headed and what I want out of my education I think that I ve decided I ll be taking a long break after I finish my B S before making any decisions about graduate school I haven t made much progress on my work for the museum it s been sort of a weird week for me but I am looking forward to making some significant progress next week Link to Post Comment on this Post 2 Comments Blog Post 3 June 22nd 2012 This week I continued to locate earthquakes with antelope I am getting much faster at picking and locating earthquakes I m able to get through about a month of data per week but there is still almost a year of data to go through I ve also been working hard on my project for the museum http www museumoftheearth org I m super excited to get kids and myself excited about earthquakes Hopefully by next week I will have some finished products that I can actually take to the museum and see how people react to them My goals for the display are to address the following questions Where do earthquakes happen Why do earthquakes happen What are waves How do waves travel through the earth What are P and S waves What can we learn from earthquakes How do we locate earthquakes I want to address these questions in fun and interactive ways I think one fun thing will to have a seismometer hooked up to a laptop so that people can do different experiments to create earthquakes and see in real time the resulting seismogram Ithaca has been great I really like it here and I have been

    Original URL path: http://www.iris.edu/hq/internship/blogs/user/57 (2015-11-11)
    Open archived version from archive

  • IRIS Internship Program - Amanda Livers
    with observing one of the shots being set off and watching a meteor shower Stay tuned next week to hear how the rest of field work went Goodbye for now Sincerely Amanda Link to Post Comment on this Post 2 Comments Week 6 July 30th 2012 After finishing up surveying for IDOR on Sunday Monday was spent cleaning the vehicles and doing last minute tire repairs Then it was back to Virginia on Tuesday The first day back at Virginia Tech Wednesday was full of data processing for SSIP I spent the day sorting the first arrival time picks The purpose of this sorting was to take the 100m spaced receivers in the valley and to choose every third receiver in order to have spacing in the valley that is similar to the spacing of receivers outside the valley Then on Thursday I used the newly sorted picks to create another tomography model This model along with the previous model were fine tuned on Friday The resulting models shown below will be used to interpret the subsurface geology of the Salton Trough The models are grouped based on the parameters used and whether the picks were sorted or not sorted The groups are organized even further by smallest to largest iteration number Iteration number is the number of times the tomography script produced a new model every third time using different smoothing The tomography models above are of non sorted picks The tomography models above are of sorted picks Stay tuned next week for my analysis of these models Goodbye for now Sincerely Amanda Link to Post Comment on this Post 0 Comments Week 5 July 26th 2012 This week was our second week in Idaho and Oregon surveying sights for IDOR The majority of our week was spent in the beautiful Idaho National Forests which was home to a diverse group of wildlife and several geological structures The photo above shows part of the survey crew in Challis National Forest Throughout the week the group got to visit a seven foot high fault scarp natural hot springs Craters of the Moon National Park and an old copper mine The following pictures show some of the things we got to see The photo above shows a natural hot spring pooling up on the left banks of a river The photo above shows a few splatter cones in Craters of the Moon National Park The photo above shows a rock collected at an old copper mine near Mackey Idaho The photo above shows an old mining building at the same copper mine Although the trees and mountains were not conducive to the GPS locating satellites it was fun to work in that environment In the forest the group saw several varieties of gophers a black bear cub mountain goats elk deer and antelope while working We successfully finished surveying the almost 3 000 sights on Sunday July 22 Our final total of flat tires came out to be ten The final total of different hotels we stayed in came out to be seven The final total of laughs and smiles came out to be too large to count I look forward to returning in August to deploy the seismometers to our surveyed sights Stay tuned next week to hear about my time back at Virginia Tech working on SSIP data Goodbye for now Sincerely Amanda Link to Post Comment on this Post 0 Comments Week 4 July 16th 2012 This past week I have been out in the wilderness of Oregon and Idaho enjoying the outdoors while working on the IDOR project The aim of this project is to use active source seismology to gather data that will be used to create a tomography model This model will be used to understand the different layers in the Earth s crust and other geological features This is similar to what I am doing with the SSIP data from line three The picture above is part of the line in Idaho I am working with a crew of eight students ranging from graduate students to undergraduates from all over the country Each day we split into teams of two and survey a portion of the IDOR line Unlike SSIP that had multiple lines IDOR consists of one long line When surveying we locate predetermined sites with a Garmin GPS and pick a suitable area for a seismometer to be buried We then label the spot with a numbered wooden stake and record the location using a Trimble GPS In August the deployment team will locate our stakes and set up the appropriate seismometer The picture above shows the four survey vehicles Each day has been an adventure Our goal is about one hundred stakes per team per day so our pace is often fast However there has been many twists and turns along the way The crew has experienced three flat tires a rattle snake and a black bear Thankfully we have all made it out safe and now know how to replace a flat tire in less than ten minutes Besides picking up useful tire changing skills we have had the opportunity to explore the local geology We have been able to climb on outcrops and have even seen several igneous dikes So far the team has collected several pounds of igneous and metamorphic rocks from these outcrops This collection includes several pieces of obsidian This leads me to my next topic Flint knapping I have been trained in flint knapping so I felt it was a great opportunity to share my knowledge with some of my fellow crew people Without handmade tools we had to use a rock as a tool I was not successful in passing my skills along but I was able to make a few little arrow heads The picture above shows some of the larger pieces of obsidian before they were thinned and a pile of flakes already taken off The picture above shows some of the

    Original URL path: http://www.iris.edu/hq/internship/blogs/user/58 (2015-11-11)
    Open archived version from archive

  • IRIS Internship Program - Rachel Petit
    experience I learned a lot which will be reflected on in my next post and met many amazing people The data is coming in now and looking great Despite minor setbacks along the way the data collection is complete and I am excited to see the results and conclusions Link to Post Comment on this Post 1 Comments Field Work Data Collection August 10th 2012 We ve made it out to the field for the deployment of the instruments The original surveying crew met up with a crew of 50 people from many different universities who have banded together to lend a hand in the deployment We ve been mostly training so far but are poised to head out into the field tomorrow to start First of all we will be deploying roughly 2600 instruments along the length of the line After that we will use explosive shots each buried 90 feet underground so that no surface damage occurs to send energy through the earth This energy will be picked up by the seismometers and downloaded after the seismometers are retrieved The roughly 24 teams will be split between two bases of operation one in the west and one in the east We will be deploying geophones connected to one channel dataloggers These dataloggers are RT125A or Texans and are primarily used for active source seismology since they have a relatively short battery life The instruments are from the IRIS PASSCAL instrument center in Socorro NM I am excited for the field work to begin and to perfect how to dig a hole with a pickax The adventure begins tomorrow morning bright and early for some and a little later for those of us heading west Link to Post Comment on this Post 1 Comments Week Six Back to Virginia July 29th 2012 After landing back in Virginia I post processed the GPS data and worked on my abstract this week In the field our teams of two were split into separate jobs one person hammered in the stake while the other person used a highly accurate GPS device called a Trimble to record the latitude longitude and elevation of the stake s location These data were stored in the device until the data from all four devices were downloaded into a university laptop Though highly accurate the accuracy of the points can be further improved through post processing I spent the first part of the week after arriving back post processing the data In essence the data is fed through a program that searches out permanent GPS locations nearby to the data point recorded by the Trimble It then uses these locations to refine the recorded locations to make the measurements more accurate which is important in the code that will be run later We are headed back to Idaho for deployment on Sunday to meet up with our large crew I am excited to be part of this project Link to Post Comment on this Post 0 Comments

    Original URL path: http://www.iris.edu/hq/internship/blogs/user/59 (2015-11-11)
    Open archived version from archive

  • IRIS Internship Program - Anna Pfohl
    the next few days By more closely examining the characteristics of each I ll have a better idea of why I haven t been able to locate tremor yet Thinking about all of this now is also going to help prepare me for writing my AGU abstract which is a relief I m still going to continue to analyze some of the data from stations that are closest to the NAF though I guess that s the good part about having the twelve hour waiting period My free time has primarily consisted of studying for the GRE and researching graduate schools It s a daunting process at this point but I m also really excited to see all the options I have available That s all for now Link to Post Comment on this Post 0 Comments Here comes the sun and heat June 29th 2012 This week I ve been turning my attention away from triggered tremor and am now on the quest for ambient tremor On Monday I received some code that has made data analysis infinitely less complicated from Stefany at Miami University she s also a former IRIS intern I ve primarily been downloading data from IRIS for the YL network so that I can analyze it all later Let me tell you this is a LOT of data There are 39 stations in this particular network and I now have data from when they were first installed some in 2005 the rest in 2006 to when they were taken down in 2008 Yesterday and today I have been working with the code Stefany gave me and it takes quite a while to process For example the first script processes data for a given station an hour at a time It takes about 12 hours to go through an entire year just for one station Once that s complete I m able to filter the seismograms similar to what I was doing before at three different frequency levels to differentiate earthquakes surface waves and of course tremor I ll include figures next week after I ve had the chance to go through more data Yesterday was a record breaking day for St Louis Apparently with a high of 108 this was the hottest day in the city in almost 60 years Yikes On the bright side literally today will be a slightly cooler 105 I ve never been so thankful for air conditioning That s all for now Link to Post Comment on this Post 1 Comments Elusive tremor June 25th 2012 I spent a majority of last week looking at seismograms so many seismograms that I swear the black squiggles are forever etched into mind but that s the nature of working in seismology so I m more than okay with it searching for tremor signals As I explained in my last post I was looking at different events in or around Turkey from 2005 to 2008 from network YL and then filtering the data

    Original URL path: http://www.iris.edu/hq/internship/blogs/user/60 (2015-11-11)
    Open archived version from archive



  •