I drove across the Bay Bridge this morning, as did many other people. Many other people did the same at that time of morning twenty years ago today as well. It was a normal drive to them; they had no idea that they wouldn't be able to drive back the way they came for their evening commute. True, I couldn't say for sure that I knew I'd be able to drive back that way this year, but with the events of twenty years ago on my mind, I think I was more aware of the possibility that it could happen again at some point in the future, near or far. I suspect that other drivers on the Bridge were thinking about it more than they might have on any other day as well.
I can't know for certain, but I suspect that this anniversary was far more on the mind of the City at large than the 1906 anniversary was, for reasons of time and experience. Loma Prieta was, after all, a smaller earthquake that didn't completely destroy the City, but it was, in the grand scheme of things, recent, and it simultaneously highlighted what an overall smaller quake can still do to a modern city, and how everyday people can be absolutely heroic in their attempts to save lives and stave off more damage. It is still a shared experience among many people here (and even those who weren't here at the time surely know people who were), rather than a historic commemoration at which the few remaining survivors are revered as living monuments. It is still very much a living memory, a community disaster.
And the City formally approached it in a way that reached into communities, rather than as a ceremony to only draw out the devoted. Specifically, street fairs with a theme of earthquake/disaster awareness and preparedness happened in four areas of the City (Mission, Marina, Bayview, and Sunset), to be followed up by more informal block parties. This did not strike me as the most intuitive way to commemorate a disaster in which 63 people died, but I still volunteered to help out. After spending the day in the Marina handing out emergency preparedness activity workbooks and painting little kids' faces, though, I think I got the idea. Earthquakes effect the whole community, and the community does need to discuss them to figure out how to best survive individually and as a group. Treating quakes like the boogeyman, like something only to be talked about in a Very Serious Environment, isn't going to promote open discussion. The fair environment, initially jarring though it was, seemed to be an effective casual space to discuss personal experiences (I heard snippets of so many people's stories of what they were doing when the quake hit - and a guy from channel 4 news seemed outright disappointed when I told him I wasn't here at the time and thus didn't have my own story, since he figured I would've had an interesting little kid perspective on it), as well as a place where people could start actively building their emergency kits from items at the various booths. The fair was not a celebration of the earthquake, but of the ability of people to withstand it and resultantly know even better what to do in the event of the next one.
The fair was followed up by a more solemn ceremony, with a set of speakers including the chief of the San Francisco Fire Department, the Marina District Supervisor, and Mayor Gavin Newsom. The theme was remembering those who had died and praising those who did so much to save lives. The ceremony also served as a dedication of a new monument to the victims, survivors, and emergency workers of Loma Prieta. The monument itself consists of the brass nozzle from the fireboat Phoenix, which saved the Marina District by pumping baywater through portable hydrants. It isn't installed yet, but was placed atop its eventual location for today's events. Both the printed program and the speeches expressed the hope that the Marina Earthquake Monument will become a sort of "21st century Lotta's Fountain," echoing the post-1906 gathering place. Yearly October 17th ceremonies seem to be the plan, though I do have to wonder how successful they'll be. The 1906 ceremony evolved from the Fountain being a central meeting place. The Phoenix's nozzle was certainly central in 1989, but the gathering of crowds wasn't. I do hope that the annual meetings take off, however, and that they continue to be an environment in which people can openly discuss what they'll do when the next one hits, as they did today.
Some other things about today's ceremony echoed the 1906 ceremony I attended in April. Everyone sang again, the same song "San Francisco" as has been a staple at Lotta's Fountain for so long. I don't think I was surprised that the same song was used, though I did find it interesting that the same thing was used to touch the living memory earthquake as to the largely historical one. There was also a definite push to get things said before the minute of the quake, so that it could be set aside from the rest of the ceremony. But where the minute of 5:12 AM on April 18th echoed back to 1906 with silence, 5:04 PM on October 17th called Loma Prieta with noise. Mayor Newsom activated a fire siren mounted on the stage, and all the fire trucks collected around the Marina Green blasted their own sirens back. The fireboat Guardian spouted three high plumes of water back over the Bay, a display that served well as a visual representation of the sound. Once the blasting faded out, a bell that tolls whenever a firefighter is injured or killed was rung in a pattern that was at once quieter than the previous barrage of sirens, but more striking against its background noise level. It was as if the sirens were screaming, "This was our earthquake! We were hit hard, but it couldn't take us down, and what did go down came back! We are stronger than this disaster!" and then the bell added, "We still can't let it happen that way again."
As I walked back to my car after cleaning up the fair area, I went past the intersection of Beach and Divisidero, where the Marina fire started and hit hardest. The post-1989 buildings there are all solid and bright and without sign of past disasters. Behind them, the sunset backlit puffs and shreds of grayish cloud with shades of orange and red. It was a beautiful sunset, but in that context, I couldn't help but think it looked rather like a fire, fortunately constrained to the sky rather than touching the buildings below, but still reminding of a tangible past and a potential future.
Saturday, October 17, 2009
Friday, October 16, 2009
Geosong: Liz Pappademas' "Loma Prieta"
It's been a long time since I posted a geology-related song (even though my collection of them has been growing steadily), but I've been waiting for just the right moment to post this one. Seeing as tomorrow is the 20th anniversary of the M6.9 Loma Prieta earthquake, I think we've come upon the right time.
I found this song by typing "Loma Prieta" into the iTunes store, as I've had to get more and more specific (or obscure) to keep expanding my playlist. Two songs with the title popped up, and I downloaded both of them. This was the one I liked better, though; the other puts the quake into a relationships context, but this one seems like it must be describing an actual real experience.
I'd never heard of Liz Pappademas before, and I still don't know how well-known she is. Her website tells me that she was raised in San Francisco, but has moved around since and is currently a resident of Los Angeles. I think I could have gathered the first part just from the lyrics to the song. It opens with, "Loma Prieta, dark hill. Shook up the San Andreas to the heart of a little girl," and goes on to be an account of a very scary experience told through the eyes of a child who has some understanding of what's going on in a physical sense, but is having more trouble with the emotional side. She describes clinging to her mother in the doorway (nevermind that you shouldn't get in the doorway!), of school being canceled, of camping out in her parents' bedroom, of expecting aftershocks, and of feeling much older after the whole experience. There's also a stanza, a little more separated from what appears to be personal experience, that describes images of 1906 being recalled by the fires in 1989. I don't know how much a little kid would or wouldn't know about 1906 as a product of a San Francisco upbringing, but I do know the comparison is consistent with some of the news media about Loma Prieta. It's certainly a moving comparison in the context of the song.
In terms of the music, "Loma Prieta" is both simple and complex. It's simple in terms of its instrumentation - mostly just voice against a piano accompaniment consisting of elaboration upon broken chords, with a little bit of electronic stuff for color. The chord sequences are not, however, your typical I-IV-V-I of so many pop songs. I'd have to sit down and think about exactly where the chords go, but the specific progression is not the point - rather, it matters more that it takes a while to get to the resolution, and there are parts that don't get resolved. The melodic line is also very free, with phrases of unequal length and pacing. It also encompasses a wider range of pitches than many pop songs do; not lingering on a specific set of pitches adds to the somewhat freeform feeling of the song. In the way the melody is shaped (and perhaps also in the broken chord piano accompaniment), "Loma Prieta" seems to be toeing the line between pop song and art song.
I very much like this song, for its subject and for its music. I think that this free and sparse style of music fits the storytelling aspect of the lyrics, and I think that the lack of any attempt to paint the words with the music allows the severity of what the singer experienced to be come all the more stark and clear. The last verse also really gets me: "Loma Prieta, dark hill. Please stay dark, I pray, please stay still."
Please stay still. This is a very human thing to plead after disaster, but the plea is made to something that cannot and will not stop moving. That particular mountain may not be shaking all the time, but the forces underneath it keep grinding steadily away, and eventually, there will be another earthquake at Loma Prieta Peak. It's inevitable, and the music seems to know it, even if the lyrics pray for it to not be so - the final cadence never quite happens.
Liz Pappademas on Rhapsody. (You can listen to the song for free there.)
I found this song by typing "Loma Prieta" into the iTunes store, as I've had to get more and more specific (or obscure) to keep expanding my playlist. Two songs with the title popped up, and I downloaded both of them. This was the one I liked better, though; the other puts the quake into a relationships context, but this one seems like it must be describing an actual real experience.
I'd never heard of Liz Pappademas before, and I still don't know how well-known she is. Her website tells me that she was raised in San Francisco, but has moved around since and is currently a resident of Los Angeles. I think I could have gathered the first part just from the lyrics to the song. It opens with, "Loma Prieta, dark hill. Shook up the San Andreas to the heart of a little girl," and goes on to be an account of a very scary experience told through the eyes of a child who has some understanding of what's going on in a physical sense, but is having more trouble with the emotional side. She describes clinging to her mother in the doorway (nevermind that you shouldn't get in the doorway!), of school being canceled, of camping out in her parents' bedroom, of expecting aftershocks, and of feeling much older after the whole experience. There's also a stanza, a little more separated from what appears to be personal experience, that describes images of 1906 being recalled by the fires in 1989. I don't know how much a little kid would or wouldn't know about 1906 as a product of a San Francisco upbringing, but I do know the comparison is consistent with some of the news media about Loma Prieta. It's certainly a moving comparison in the context of the song.
In terms of the music, "Loma Prieta" is both simple and complex. It's simple in terms of its instrumentation - mostly just voice against a piano accompaniment consisting of elaboration upon broken chords, with a little bit of electronic stuff for color. The chord sequences are not, however, your typical I-IV-V-I of so many pop songs. I'd have to sit down and think about exactly where the chords go, but the specific progression is not the point - rather, it matters more that it takes a while to get to the resolution, and there are parts that don't get resolved. The melodic line is also very free, with phrases of unequal length and pacing. It also encompasses a wider range of pitches than many pop songs do; not lingering on a specific set of pitches adds to the somewhat freeform feeling of the song. In the way the melody is shaped (and perhaps also in the broken chord piano accompaniment), "Loma Prieta" seems to be toeing the line between pop song and art song.
I very much like this song, for its subject and for its music. I think that this free and sparse style of music fits the storytelling aspect of the lyrics, and I think that the lack of any attempt to paint the words with the music allows the severity of what the singer experienced to be come all the more stark and clear. The last verse also really gets me: "Loma Prieta, dark hill. Please stay dark, I pray, please stay still."
Please stay still. This is a very human thing to plead after disaster, but the plea is made to something that cannot and will not stop moving. That particular mountain may not be shaking all the time, but the forces underneath it keep grinding steadily away, and eventually, there will be another earthquake at Loma Prieta Peak. It's inevitable, and the music seems to know it, even if the lyrics pray for it to not be so - the final cadence never quite happens.
Liz Pappademas on Rhapsody. (You can listen to the song for free there.)
Wednesday, September 23, 2009
Southern California Earthquake Center meeting, 2009
I live! And not only do I live, but I've had an intensely busy and extremely productive August and September, with a combination of conferences, personal travel, research, and many many hours of work (and hours of sleep lost) on an outreach project called "Faults of California." I'll post more extensively about that project once it's at the point where I can actually show it to you, but for those of you who follow me on Twitter, this is related to all of the stuff I've been posting about "talking faults" and "comic books."
Anyway! Last week was the annual Southern California Earthquake Center meeting in Palm Springs. Last year's SCEC meeting was my very first scientific conference ever, and even though I went before I'd had any graduate level earth science classes, I still came out of it with tons of ideas for things I wanted to research. This year, now that I've been taking seminars and doing research all year, was even better. I had a much better overall understanding of posters and talks, but even more important, I was much better able to really converse with the people stopping by my poster or the people whose posters I visited, rather than merely explaining what I did, or merely listening to their own explanations. So, in addition to giving me yet another huge load of ideas I'd love to research/model, this year's SCEC meeting also served as a good marker for what a year of work can do. I'm certainly not thinking of myself as "that hack with a music degree" as much as I used to!
A hopefully-brief day-to-day rundown of the meeting:
Saturday, 12 September
Arrived in Palm Springs by 9:30 AM, for the beginning of a workshop on dynamic weakening mechanisms at 10 AM. The research presented in this workshop consisted primarily of laboratory experiments on various types of rock and fault gouge, most of which used a rotary shear device, though with different sets of stresses and different effects being observed. The particular focus seemed to be on assorted flash heating effects, and also the possibility of gels being created from fluid and silica on faults. There seemed to be a little frictional heating between the differing presenters, who sometimes disagreed on each other's experimental setups or interpretation of results, but even with the debate, it was enlightening to see some of the experimental work that goes into the friction laws and fault behavior equations that are coded into the modeling software I use on a regular basis. Toward the end of the day, I slipped out to hear a friend's talk in a workshop on transient detection; his talk was quite clear and well-delivered, though the other two before it were far too caught up in a type of math I haven't yet learned to make any sense to me.
Sunday, 13 September
The second annual SCEC student field trip was to San Gorgonio Pass. This area is particularly intriguing to me because it's a total mess of fault geometry, with curves, bends, branches, and stepovers, with transitions from strike-slip to thrust and back again. This is the kind of crazy complexity I'd love to model at some point, and getting to actually walk all over it and see contact points and evidence of the collision of the Mt. San Jacinto block with the San Bernardino Mountains brought the details of this unusual area far more into light than only reading about them would have. The field trip focused on features associated with these transitions in fault behavior: we looked at strike-slip features like shutter ridges in alluvial fans near Garnet Hill and an incredibly clear juxtaposition of schist and sediment in Whitewater Canyon (where I'd helped install a seismic array last October - guess my back was to this contact point the whole time then!), but only a few kilometers to the northwest, there were 12-meter thrust fault scarps. The last stop was the southern terminus of the clearly-mapped continuous San Andreas Fault. North of there, the Fault can be followed clear through to Point Arena, but the whole San Gorgonio knot to the south still hasn't been unraveled. Seeing these features and talking with the trip leaders gave me a ton of ideas for specific questions to ask and points to finetune in future modeling, and fortunately, the trip leaders said I could continue to pick their brains on this matter as I get into modeling specific faults. After the trip, I hung my poster, and also helped set up the "Faults of California" display in the hallway. It was very odd to have my artwork taking up a whole hallway, though I didn't stand next to it. I put a sign next to it directing people to find me at my research poster - a way to get people to talk to me about both!
Monday, 14 September
The meeting proper started on the 14th. Unlike last year, which separated out organizational discussions for different branches of SCEC, this year had a scientific talk followed by an organization-wide planning session at least tangentially related to the topic of the talk. Monday's talks concerned tremor on the San Andreas at Parkfield (and how it connects to repeating microearthquakes), and how earthquake scientists and engineers can better communicate with each other about their work and needs. I don't remember as much about the objectives discussions on this day as on Tuesday; I admittedly paid a little less attention since they were related to the parts of SCEC less related to my own work, and thus were issues about which I had no particular opinion. I hope - and suspect - that I'll be able to get more and more out of these more distant topics with each consecutive SCEC meeting. The thing I got the most out of on Monday was the poster session; my poster was about the effect of fault stepovers on ground motion, and it was therefore filed with the ground motion group as opposed to the rupture mechanics group. I ended up having a huge amount of traffic and discussion around my poster for both the afternoon and evening session, to the point where I didn't even get a chance to look at any of the other posters. A good problem to have, particularly considering how many ideas for things to look at within the scope of this project I got out of it!
Tuesday, 15 September
Tuesday's plenary talks were another take on dynamic weakening mechanisms (which included video of one rock sample exploding on the shear apparatus), whether or not the Gutenberg-Richter relation actually applies to faults, and a look at the southern California crust with seismic tomography. Of these, the Gutenberg-Richter one prompted the most discussion, in the form of a very heated debate that cut into planning time and continued to crop up in discussion for the rest of the whole conference. It was not enough to entirely deflect the discussion of what modelers and field geologists can do for each other, however. This planning session included the request for more detailed maps of fault geometry (yay!), with the possibility of a community fault mesh that anyone could adapt to their models without having to remesh anything. I certainly hope that these things come to pass, since limited understanding of geometry and the problems of meshing the complexity we do know about put some definite limits on modeling. The rupture dynamics posters were up in the Tuesday session, but once again, I was kept from getting to see very many of them because I was held up at my own work. I didn't plan to hover near the "Faults of California" printout in the hallway, but people dropped by to ask things, and before I knew it, the afternoon session was over. In the evening, I got to walk around the other posters for a few minutes, but then I had a meeting with the guy in charge of education at SCEC to discuss specific things to be done with "Faults of California." It was a very productive talk, even though I missed so many posters. Good thing there are abstracts in the conference program booklet...
Wednesday, 16 September
There was only one plenary talk on Wednesday, and it had to do with earthquake forecasting (but not earthquake prediction). It was an interesting talk, but the planning session afterward was even more interesting to me. I forget the prompt exactly, but it got onto the matter of fault systems and geometry, and there seems to be general agreement that the next phase of SCEC should include an objective for major focus on interactions between faults. There was specific mention of the San Andreas/Garlock intersection, which is of particular interest to me. I'll be pretty far into my PhD work by the time SCEC4 actually starts (2012), but if that work is in an area that's one of the main objectives, that will hopefully mean good things in terms of postdocs or jobs in the future.
I guess I failed at being brief (I guess I had to unload a lot of words after sitting there silently for two months!), but I reiterate that it was an awesome conference overall, and I have a lot more to think about and do over this year and the next few thanks to it.
(And I will hopefully be able to post more about "Faults of California" soon. In the meantime, now that the bulk of work on it is done, I should be posting here more in general. I hope.)
Anyway! Last week was the annual Southern California Earthquake Center meeting in Palm Springs. Last year's SCEC meeting was my very first scientific conference ever, and even though I went before I'd had any graduate level earth science classes, I still came out of it with tons of ideas for things I wanted to research. This year, now that I've been taking seminars and doing research all year, was even better. I had a much better overall understanding of posters and talks, but even more important, I was much better able to really converse with the people stopping by my poster or the people whose posters I visited, rather than merely explaining what I did, or merely listening to their own explanations. So, in addition to giving me yet another huge load of ideas I'd love to research/model, this year's SCEC meeting also served as a good marker for what a year of work can do. I'm certainly not thinking of myself as "that hack with a music degree" as much as I used to!
A hopefully-brief day-to-day rundown of the meeting:
Saturday, 12 September
Arrived in Palm Springs by 9:30 AM, for the beginning of a workshop on dynamic weakening mechanisms at 10 AM. The research presented in this workshop consisted primarily of laboratory experiments on various types of rock and fault gouge, most of which used a rotary shear device, though with different sets of stresses and different effects being observed. The particular focus seemed to be on assorted flash heating effects, and also the possibility of gels being created from fluid and silica on faults. There seemed to be a little frictional heating between the differing presenters, who sometimes disagreed on each other's experimental setups or interpretation of results, but even with the debate, it was enlightening to see some of the experimental work that goes into the friction laws and fault behavior equations that are coded into the modeling software I use on a regular basis. Toward the end of the day, I slipped out to hear a friend's talk in a workshop on transient detection; his talk was quite clear and well-delivered, though the other two before it were far too caught up in a type of math I haven't yet learned to make any sense to me.
Sunday, 13 September
The second annual SCEC student field trip was to San Gorgonio Pass. This area is particularly intriguing to me because it's a total mess of fault geometry, with curves, bends, branches, and stepovers, with transitions from strike-slip to thrust and back again. This is the kind of crazy complexity I'd love to model at some point, and getting to actually walk all over it and see contact points and evidence of the collision of the Mt. San Jacinto block with the San Bernardino Mountains brought the details of this unusual area far more into light than only reading about them would have. The field trip focused on features associated with these transitions in fault behavior: we looked at strike-slip features like shutter ridges in alluvial fans near Garnet Hill and an incredibly clear juxtaposition of schist and sediment in Whitewater Canyon (where I'd helped install a seismic array last October - guess my back was to this contact point the whole time then!), but only a few kilometers to the northwest, there were 12-meter thrust fault scarps. The last stop was the southern terminus of the clearly-mapped continuous San Andreas Fault. North of there, the Fault can be followed clear through to Point Arena, but the whole San Gorgonio knot to the south still hasn't been unraveled. Seeing these features and talking with the trip leaders gave me a ton of ideas for specific questions to ask and points to finetune in future modeling, and fortunately, the trip leaders said I could continue to pick their brains on this matter as I get into modeling specific faults. After the trip, I hung my poster, and also helped set up the "Faults of California" display in the hallway. It was very odd to have my artwork taking up a whole hallway, though I didn't stand next to it. I put a sign next to it directing people to find me at my research poster - a way to get people to talk to me about both!
Monday, 14 September
The meeting proper started on the 14th. Unlike last year, which separated out organizational discussions for different branches of SCEC, this year had a scientific talk followed by an organization-wide planning session at least tangentially related to the topic of the talk. Monday's talks concerned tremor on the San Andreas at Parkfield (and how it connects to repeating microearthquakes), and how earthquake scientists and engineers can better communicate with each other about their work and needs. I don't remember as much about the objectives discussions on this day as on Tuesday; I admittedly paid a little less attention since they were related to the parts of SCEC less related to my own work, and thus were issues about which I had no particular opinion. I hope - and suspect - that I'll be able to get more and more out of these more distant topics with each consecutive SCEC meeting. The thing I got the most out of on Monday was the poster session; my poster was about the effect of fault stepovers on ground motion, and it was therefore filed with the ground motion group as opposed to the rupture mechanics group. I ended up having a huge amount of traffic and discussion around my poster for both the afternoon and evening session, to the point where I didn't even get a chance to look at any of the other posters. A good problem to have, particularly considering how many ideas for things to look at within the scope of this project I got out of it!
Tuesday, 15 September
Tuesday's plenary talks were another take on dynamic weakening mechanisms (which included video of one rock sample exploding on the shear apparatus), whether or not the Gutenberg-Richter relation actually applies to faults, and a look at the southern California crust with seismic tomography. Of these, the Gutenberg-Richter one prompted the most discussion, in the form of a very heated debate that cut into planning time and continued to crop up in discussion for the rest of the whole conference. It was not enough to entirely deflect the discussion of what modelers and field geologists can do for each other, however. This planning session included the request for more detailed maps of fault geometry (yay!), with the possibility of a community fault mesh that anyone could adapt to their models without having to remesh anything. I certainly hope that these things come to pass, since limited understanding of geometry and the problems of meshing the complexity we do know about put some definite limits on modeling. The rupture dynamics posters were up in the Tuesday session, but once again, I was kept from getting to see very many of them because I was held up at my own work. I didn't plan to hover near the "Faults of California" printout in the hallway, but people dropped by to ask things, and before I knew it, the afternoon session was over. In the evening, I got to walk around the other posters for a few minutes, but then I had a meeting with the guy in charge of education at SCEC to discuss specific things to be done with "Faults of California." It was a very productive talk, even though I missed so many posters. Good thing there are abstracts in the conference program booklet...
Wednesday, 16 September
There was only one plenary talk on Wednesday, and it had to do with earthquake forecasting (but not earthquake prediction). It was an interesting talk, but the planning session afterward was even more interesting to me. I forget the prompt exactly, but it got onto the matter of fault systems and geometry, and there seems to be general agreement that the next phase of SCEC should include an objective for major focus on interactions between faults. There was specific mention of the San Andreas/Garlock intersection, which is of particular interest to me. I'll be pretty far into my PhD work by the time SCEC4 actually starts (2012), but if that work is in an area that's one of the main objectives, that will hopefully mean good things in terms of postdocs or jobs in the future.
I guess I failed at being brief (I guess I had to unload a lot of words after sitting there silently for two months!), but I reiterate that it was an awesome conference overall, and I have a lot more to think about and do over this year and the next few thanks to it.
(And I will hopefully be able to post more about "Faults of California" soon. In the meantime, now that the bulk of work on it is done, I should be posting here more in general. I hope.)
Monday, July 27, 2009
NMCDEF 2009
As evidenced by the vague conference-y posts on my Twitter account a few weeks ago, I was indeed at a conference from 22-26 June: the Numerical Modeling of Crustal Deformation and Earthquake Faulting workshop, in Golden, Colorado.
(I started writing this up right away, and then my computer crapped out. It took me this long to feel motivated to rewrite the post. Oy.)
This is a small conference (they capped participation at 60 people), and is just as oriented around collaboration on modeling problems using Computational Infrastructure for Geophysics software as it is around science talks. (It was not poster-oriented at all, though a bunch of us did bring posters. They were taped on the walls around the conference room, but not many people seemed to look at them; they instead used poster session time for software tinkering.) There were people with a wide range of specialties in attendance, from people focused specifically on earthquake physics to engineers working in plasticity to mathematicians who had only recently started delving into earth science applications, not to mention all the code-focused people. Among the people I spoke with, it seemed like I was one of the few there who were working specifically on rupture dynamics, which was an interesting change from the groups of people I spoke most with at SCEC and AGU.
I admittedly felt pretty out of place for the code-focused parts of the workshop, which filled the afternoons of the first four days, and the entirety of the fifth day (though I spent much of the fifth day doing airport things instead). Though I have been running lots of fault models over the course of the past year, they have all been with only one mesher and one finite element code, both of which were written from the ground up by a former student of my advisor's. It's a very good code for what I'm doing, and part of the reason we've been using it exclusively is to get it out there more. But I have no experience using other code yet, nor in more than the slightest tweaking of the code we have. My only codewriting experience was a C++ class that I took in 1999 (I'll be taking more in the future, though). As a result, all the nuts and bolts coder discussion went right over my head and made me doubt myself about being at the conference at all. I did want to participate in the tutorials for the code more actively, though, even if none of the things presented actually included friction and dynamic rupture at the time being. (I understand these will be included in future versions.) At this point, I ran into the problem that neither mesher would work on my laptop, nor would one of the physics codes. Turns out that I needed to be running Leopard, and I was still on Tiger, so I had to look on at other people's progress instead of poking around on my own. (I decided to upgrade to Leopard when I got back to Riverside, and as luck would have it, I got a bad disk. This ended in me having to wipe my hard drive and install from a different copy.)
But for all the code stuff left me feeling like the newbie that I am, the science talks totally made up for it. In general, it was very useful to see how many other ways people are using finite element models to examine earthquakes and crustal deformation, since I was taught about them specifically in the context of rupture mechanics. One that was particularly exciting to me involved a different fault setup in terms of type and geometry, but ultimately a similar sort of stress barrier condition to the models I've been running all year. The shape of the curves delineating whether or not the rupture propagated through the barrier for a given stress case was very similar to the shape of the curve I found for whether or not rupture propagates through a given type of stepover. (Not going to say more about that, though, since neither paper is in press yet!) I was also particularly intrigued by a talk involving geologically-derived information on interactions between the San Andreas, Garlock, and Eastern California Shear Zone; this is the kind of material I'm already reading up on in anticipation of what I'll be doing after the Master's stuff. In addition to these, there were several talks on subduction, several on effects of plasticity, one on the East African Rift, one on Mt. Redoubt, one on compliant zones around Mojave faults, and a couple more specific to small-scale rock mechanics. Definitely a good eye-opening representation of what people are modeling beyond the coseismic part of the earthquake cycle!
So, on the whole, a good conference, even for the stress of not being a codehead. I'm hoping that, if the department thinks I should go again next year, I'll also have more experience with code-specific matters. Even if I'm not actually messing with the code, I should at least have experience with several more programs by then, and I know I'll be able to run their code now that I've upgraded my OS.
(I started writing this up right away, and then my computer crapped out. It took me this long to feel motivated to rewrite the post. Oy.)
This is a small conference (they capped participation at 60 people), and is just as oriented around collaboration on modeling problems using Computational Infrastructure for Geophysics software as it is around science talks. (It was not poster-oriented at all, though a bunch of us did bring posters. They were taped on the walls around the conference room, but not many people seemed to look at them; they instead used poster session time for software tinkering.) There were people with a wide range of specialties in attendance, from people focused specifically on earthquake physics to engineers working in plasticity to mathematicians who had only recently started delving into earth science applications, not to mention all the code-focused people. Among the people I spoke with, it seemed like I was one of the few there who were working specifically on rupture dynamics, which was an interesting change from the groups of people I spoke most with at SCEC and AGU.
I admittedly felt pretty out of place for the code-focused parts of the workshop, which filled the afternoons of the first four days, and the entirety of the fifth day (though I spent much of the fifth day doing airport things instead). Though I have been running lots of fault models over the course of the past year, they have all been with only one mesher and one finite element code, both of which were written from the ground up by a former student of my advisor's. It's a very good code for what I'm doing, and part of the reason we've been using it exclusively is to get it out there more. But I have no experience using other code yet, nor in more than the slightest tweaking of the code we have. My only codewriting experience was a C++ class that I took in 1999 (I'll be taking more in the future, though). As a result, all the nuts and bolts coder discussion went right over my head and made me doubt myself about being at the conference at all. I did want to participate in the tutorials for the code more actively, though, even if none of the things presented actually included friction and dynamic rupture at the time being. (I understand these will be included in future versions.) At this point, I ran into the problem that neither mesher would work on my laptop, nor would one of the physics codes. Turns out that I needed to be running Leopard, and I was still on Tiger, so I had to look on at other people's progress instead of poking around on my own. (I decided to upgrade to Leopard when I got back to Riverside, and as luck would have it, I got a bad disk. This ended in me having to wipe my hard drive and install from a different copy.)
But for all the code stuff left me feeling like the newbie that I am, the science talks totally made up for it. In general, it was very useful to see how many other ways people are using finite element models to examine earthquakes and crustal deformation, since I was taught about them specifically in the context of rupture mechanics. One that was particularly exciting to me involved a different fault setup in terms of type and geometry, but ultimately a similar sort of stress barrier condition to the models I've been running all year. The shape of the curves delineating whether or not the rupture propagated through the barrier for a given stress case was very similar to the shape of the curve I found for whether or not rupture propagates through a given type of stepover. (Not going to say more about that, though, since neither paper is in press yet!) I was also particularly intrigued by a talk involving geologically-derived information on interactions between the San Andreas, Garlock, and Eastern California Shear Zone; this is the kind of material I'm already reading up on in anticipation of what I'll be doing after the Master's stuff. In addition to these, there were several talks on subduction, several on effects of plasticity, one on the East African Rift, one on Mt. Redoubt, one on compliant zones around Mojave faults, and a couple more specific to small-scale rock mechanics. Definitely a good eye-opening representation of what people are modeling beyond the coseismic part of the earthquake cycle!
So, on the whole, a good conference, even for the stress of not being a codehead. I'm hoping that, if the department thinks I should go again next year, I'll also have more experience with code-specific matters. Even if I'm not actually messing with the code, I should at least have experience with several more programs by then, and I know I'll be able to run their code now that I've upgraded my OS.
Thursday, June 18, 2009
Time Warp: Destination 1906
Lockwood had to poke me that the Accretionary Wedge is stumbling back to its feet, but it was good timing for a poke, since the quarter has just ended, and I might actually have time to write things other than comments on the undergrad papers I've been grading. (More on my insane past quarter later.) Anyway, I was initially concerned that I wouldn't be able to think of a topic and come up with an even vaguely eloquent post by the end of the grace period for late entries.
And then I saw the actual topic. No need to brainstorm here! I'm sure that every single one of you who has followed my blog, sparse though it's been lately, knows where and when I'd take my time machine. My choice definitely does not, however, come from any sort of desire to watch the destruction of a major city and the combustion of thousands of lives within. The decision to set the time machine for San Francisco in April of 1906 comes from an intense interest in earthquakes as events and processes, a great love for the city in question, and a fascination with the development of the field of earthquake physics itself.
I'll admit right out that I am curious what it feels like to be in a M7.8 earthquake. So far, my personal experience maxes out at M5.4, which was entirely exciting and not at all terrifying in my book. I suspect M7.8 would be well past the boundary between excitement and fear, but I suppose I wouldn't be afraid of the idea of that fear if I were gearing up my time machine to experience it. Furthermore, the bigger quakes are the ones that get the most intensive study, and while my own models are currently producing things that, according to the length of the faults, might not top the mid-6 range, I'll eventually be dealing in 7-pointers, and I want to know what one is like. For this curiosity, a time machine is a preferable option to waiting for a real one, both because it eliminates the waiting to begin with, and also because it means we wouldn't need a new 7.8 to appease any seismologist who might have this same curiosity. Of course, there's bound to be another one sooner than later, geologically-speaking, but the longer we put the new one off, the more we come to know about the processes behind it, and the more we can prepare our cities and citizens. The old quake already did its damage, horrendous though it was.
And that brings me to another point - I would not want to be in San Francisco proper to experience this earthquake. Even if my time machine were to make me impervious to flying bricks and walls of flame, I'd still want to be waiting somewhere where I could see the fault rip its way down the peninsula. I once read an account of a woman in Idaho who watched a fault rip through her property. She described it as if the fault scarp were being painted across the landscape by a very fast brush. That definitely seems like some sort of juncture between fear and awe, and that is absolutely something I'd want to see. My odds of merely experiencing a non-anachronistic 7.8 are much higher than of me watching the fault break in the process of creating that 7.8. Once the rupture passed me by, however, I think I would want to get back to the City as fast as possible, to see what damage the earthquake alone did before the fires took over...and then I'd want to get back to safer ground quite quickly as well, to avoid being caught by the flames.
But I could see a surface rupture for so many other earthquakes. Why turn my time machine toward this one? That, I'll admit, comes from my feeling extremely attached to San Francisco - never mind that I've never lived there! In making my plans to jaunt back 103 years, I'd build in a little extra time before April 18th - maybe I'd show up at the beginning of the month - so that I could explore the old San Francisco before it got wiped off the map. There are plenty of words about it, but in describing the before and after case, whose prose wouldn't be biased by what they'd just gone through? And, of course, who would have known to take before photos, if they had no reason to expect an after? The 1906 earthquake might have been the first extensively photographed natural disaster, but pre-quake images are hard to come by. I'd want to spend time just wandering the place, as I explore places when I visit them now, getting to know the streets and buildings and characters as they were before their disruption. If I were allowed modern technology aside from my time machine, I might try to snap some photos. If not, I'd plan to blow through a sketchbook or two. I might also be tempted to try and get a seat (or, more likely, a place to stand in the gallery) at the infamous Metropolitan Opera showing of Bizet's Carmen on the evening of April 17th, both because of the infamy of the event, but also because I am still a music geek, switch of majors or not! I've never seen Carmen live, and were I to have the opportunity to see Caruso in it, well, that's an excitement I'd share with many of those 1906 San Franciscans. It might even be a strange way to lose track of my hindsight for a few hours - just so long as I was sure to get it back in time to get out to the fault trace!
When I say that I'd want to get out of danger in the City once the fire started, though, I do not mean I wish to zap myself immediately back to 2009. I would be willing to handle the discomfort of the survivor camps for the sake of historical and cultural understanding, but also as a way to wait for the less ominous aftermath. Before the 1906 earthquake, so very little was known about faults and how they work, and the still-nameless San Andreas Fault was thought to be a small discontinuity in rock type not extending beyond part of San Mateo County. I would love to get myself an in with the scientific community of the day and watch the progression from knowing nothing of the earthquake source to "do the earthquakes cause the faults, or do the faults cause the earthquakes?" to the oh-so-fundamental elastic rebound theory. I would be so excited to watch the faults of California get drawn in on the map for the first time, outlining mountain ranges, bounding geologic provinces, highlighting the network of hazard that we still strive to understand and mitigate today. And to be able to witness that while also observing the rebuilding of San Francisco...Definitely a time of wonder and excitement, even though it came out of tragedy.
I suppose that all means I'd be staying until 1910. A bit of an extended trip, in terms of humanity, but not even a blink in geologic time. And since a time machine could be set to return to the exact time and place from whence it came, it wouldn't even be a blink at all to the current world that includes my timeline. It might mean four years off from my research, but I'd come back from it with a closer connection to where what I'm doing comes from, both in terms of scientific roots and in terms of seeing first hand what these natural processes we study can do.
And then I saw the actual topic. No need to brainstorm here! I'm sure that every single one of you who has followed my blog, sparse though it's been lately, knows where and when I'd take my time machine. My choice definitely does not, however, come from any sort of desire to watch the destruction of a major city and the combustion of thousands of lives within. The decision to set the time machine for San Francisco in April of 1906 comes from an intense interest in earthquakes as events and processes, a great love for the city in question, and a fascination with the development of the field of earthquake physics itself.
I'll admit right out that I am curious what it feels like to be in a M7.8 earthquake. So far, my personal experience maxes out at M5.4, which was entirely exciting and not at all terrifying in my book. I suspect M7.8 would be well past the boundary between excitement and fear, but I suppose I wouldn't be afraid of the idea of that fear if I were gearing up my time machine to experience it. Furthermore, the bigger quakes are the ones that get the most intensive study, and while my own models are currently producing things that, according to the length of the faults, might not top the mid-6 range, I'll eventually be dealing in 7-pointers, and I want to know what one is like. For this curiosity, a time machine is a preferable option to waiting for a real one, both because it eliminates the waiting to begin with, and also because it means we wouldn't need a new 7.8 to appease any seismologist who might have this same curiosity. Of course, there's bound to be another one sooner than later, geologically-speaking, but the longer we put the new one off, the more we come to know about the processes behind it, and the more we can prepare our cities and citizens. The old quake already did its damage, horrendous though it was.
And that brings me to another point - I would not want to be in San Francisco proper to experience this earthquake. Even if my time machine were to make me impervious to flying bricks and walls of flame, I'd still want to be waiting somewhere where I could see the fault rip its way down the peninsula. I once read an account of a woman in Idaho who watched a fault rip through her property. She described it as if the fault scarp were being painted across the landscape by a very fast brush. That definitely seems like some sort of juncture between fear and awe, and that is absolutely something I'd want to see. My odds of merely experiencing a non-anachronistic 7.8 are much higher than of me watching the fault break in the process of creating that 7.8. Once the rupture passed me by, however, I think I would want to get back to the City as fast as possible, to see what damage the earthquake alone did before the fires took over...and then I'd want to get back to safer ground quite quickly as well, to avoid being caught by the flames.
But I could see a surface rupture for so many other earthquakes. Why turn my time machine toward this one? That, I'll admit, comes from my feeling extremely attached to San Francisco - never mind that I've never lived there! In making my plans to jaunt back 103 years, I'd build in a little extra time before April 18th - maybe I'd show up at the beginning of the month - so that I could explore the old San Francisco before it got wiped off the map. There are plenty of words about it, but in describing the before and after case, whose prose wouldn't be biased by what they'd just gone through? And, of course, who would have known to take before photos, if they had no reason to expect an after? The 1906 earthquake might have been the first extensively photographed natural disaster, but pre-quake images are hard to come by. I'd want to spend time just wandering the place, as I explore places when I visit them now, getting to know the streets and buildings and characters as they were before their disruption. If I were allowed modern technology aside from my time machine, I might try to snap some photos. If not, I'd plan to blow through a sketchbook or two. I might also be tempted to try and get a seat (or, more likely, a place to stand in the gallery) at the infamous Metropolitan Opera showing of Bizet's Carmen on the evening of April 17th, both because of the infamy of the event, but also because I am still a music geek, switch of majors or not! I've never seen Carmen live, and were I to have the opportunity to see Caruso in it, well, that's an excitement I'd share with many of those 1906 San Franciscans. It might even be a strange way to lose track of my hindsight for a few hours - just so long as I was sure to get it back in time to get out to the fault trace!
When I say that I'd want to get out of danger in the City once the fire started, though, I do not mean I wish to zap myself immediately back to 2009. I would be willing to handle the discomfort of the survivor camps for the sake of historical and cultural understanding, but also as a way to wait for the less ominous aftermath. Before the 1906 earthquake, so very little was known about faults and how they work, and the still-nameless San Andreas Fault was thought to be a small discontinuity in rock type not extending beyond part of San Mateo County. I would love to get myself an in with the scientific community of the day and watch the progression from knowing nothing of the earthquake source to "do the earthquakes cause the faults, or do the faults cause the earthquakes?" to the oh-so-fundamental elastic rebound theory. I would be so excited to watch the faults of California get drawn in on the map for the first time, outlining mountain ranges, bounding geologic provinces, highlighting the network of hazard that we still strive to understand and mitigate today. And to be able to witness that while also observing the rebuilding of San Francisco...Definitely a time of wonder and excitement, even though it came out of tragedy.
I suppose that all means I'd be staying until 1910. A bit of an extended trip, in terms of humanity, but not even a blink in geologic time. And since a time machine could be set to return to the exact time and place from whence it came, it wouldn't even be a blink at all to the current world that includes my timeline. It might mean four years off from my research, but I'd come back from it with a closer connection to where what I'm doing comes from, both in terms of scientific roots and in terms of seeing first hand what these natural processes we study can do.
Saturday, May 23, 2009
Seismology By Text Message
Now here's something I would have shoved everything else out of the agenda to post - had my internet not been down all week. It is so great having it back, let me tell you!
Anyway. I have a well-deserved reputation among my friends for being the geekiest of the geeky when it comes to earthquakes. As a result, a lot of my friends send me text messages whenever they feel a shake - even if it turns out to be a false alarm. After the quake in San Bernardino this January, I received messages from five different people within the first two minutes.
Some of those five people were out of town this past Sunday, but I still got two texts immediately following the M4.7 on the Newport-Inglewood Fault. I did feel the quake quite distinctly here in Riverside (it right after the conclusion of an orchestral and choral concert in which I'd played - if it had been five minutes sooner, it would have been a very interesting climax to the piece!); it started fairly sharply but was mostly rolling after that. It lasted long enough that I figured it was of a decent size but not particularly close.
The first text message came from a friend in Burbank. It came so soon after the shaking had stopped in Riverside that I immediately knew the source had to be closer to there than to here, since even the most intrepid of texters can't go that fast on tiny cell phone buttons. Within a minute, I got another message from a friend who lives down the street from me in Riverside. Both of them asked me whether or not I felt it, and how big it was. I told them I didn't know how big yet (and didn't find out until over an hour later, due to my stupid internet being down), but that I at least had some travel time information!
I also felt the M4.0 aftershock on Tuesday. It came during the midterm for the class I'm TAing, and while the urge was great to shout, "Did you feel that?" to an audience of several hundred, I didn't want to be a bad proctor and disrupt any test taking. When polled after everything was handed in, about half the class said they felt a wiggle. When I encouraged my discussion sections two days later to fill out the Did You Feel It? questionnaire, one student asked if the quake is why I'd practically skipped down the aisle of the lecture hall to talk excitedly with the professor. D'oh!
As I said, I have a reputation.
Anyway. I have a well-deserved reputation among my friends for being the geekiest of the geeky when it comes to earthquakes. As a result, a lot of my friends send me text messages whenever they feel a shake - even if it turns out to be a false alarm. After the quake in San Bernardino this January, I received messages from five different people within the first two minutes.
Some of those five people were out of town this past Sunday, but I still got two texts immediately following the M4.7 on the Newport-Inglewood Fault. I did feel the quake quite distinctly here in Riverside (it right after the conclusion of an orchestral and choral concert in which I'd played - if it had been five minutes sooner, it would have been a very interesting climax to the piece!); it started fairly sharply but was mostly rolling after that. It lasted long enough that I figured it was of a decent size but not particularly close.
The first text message came from a friend in Burbank. It came so soon after the shaking had stopped in Riverside that I immediately knew the source had to be closer to there than to here, since even the most intrepid of texters can't go that fast on tiny cell phone buttons. Within a minute, I got another message from a friend who lives down the street from me in Riverside. Both of them asked me whether or not I felt it, and how big it was. I told them I didn't know how big yet (and didn't find out until over an hour later, due to my stupid internet being down), but that I at least had some travel time information!
I also felt the M4.0 aftershock on Tuesday. It came during the midterm for the class I'm TAing, and while the urge was great to shout, "Did you feel that?" to an audience of several hundred, I didn't want to be a bad proctor and disrupt any test taking. When polled after everything was handed in, about half the class said they felt a wiggle. When I encouraged my discussion sections two days later to fill out the Did You Feel It? questionnaire, one student asked if the quake is why I'd practically skipped down the aisle of the lecture hall to talk excitedly with the professor. D'oh!
As I said, I have a reputation.
Sunday, May 17, 2009
A day of kinematic GPS
I really don't mean to be neglecting my blog (or neglecting commenting on your blogs) as much as I have been lately. It's mostly that, after the classes and the rehearsals and the homework and the grading, I put aside the papers and think only of sleep, rather than of spending more time at a screen writing things. I'm accumulating a rather lengthy To-Blog list, which, following Maria's lead> I think I'll have to make a summer break resolution (since New Year's is way too far off) to actually write up.
Anyway, though much of my time this quarter has been spent at a desk, the seminar I'm taking on tectonic geomorphology and quaternary field methods has served well to get me out and about. Many of our "trips" have been into the hills behind campus, mostly for funding reasons, but we have had a few larger outings. The most intensive one so far was when we went to Grass Valley in the San Bernardino Mountains to make a digital elevation map using kinematic GPS. (There was also a USGS/Caltech team out there using LiDAR to image some precariously balanced rocks, but we did not get to actively participate in this part of the work; we were mere observers.)
Grass Valley is located in the San Bernardino Mountains, not far from Lake Arrowhead. It falls into the region of highest possible threat of major earthquake ground motion in the state, due to its proximity to several major faults. The San Andreas Fault is 11 kilometers away, with several well-constrained paleoseismic sites within 20 km. The San Jacinto Fault is only a kilometer or two further away than the San Andreas; the north frontal thrust of the San Bernardino Mountains is about the same distance away to the north. The Cleghorn Fault runs directly through Grass Valley, though its activity isn't as well constrained; there's no current microseismicity, and no evidence of Holocene rupture.
The precariously balanced rock team was clearly there to try and constrain whether or not the worst case scenario of shaking according to the state hazard report had actually ever happened since those rocks became precarious to begin with. The focus of the class exercise, however, was more on a catchment containing a small system of drainages in the process of being captured by the Mojave River. Our goal was to use kinematic GPS to get a good picture of the area, which could then be used to better situate the precariously balanced rocks in the middle of the site.
Kinematic GPS is a method of relative measurement. Actual latitude/longitude figures don't come into play. All measurements are taken relative to a base station that gets set up somewhere central in the site, for the express purpose of kinematic GPS measurement. People then carry portable GPS antennae, either attached to a backpack or on a long pole, all over the area surrounding the base station. The goal is to go back and forth over all of the bumps and dips in topography - even though that does, of course, make for harder hiking at times - to make sure they show up in the DEM. The data has to be corrected for height of the person carrying the antenna (I was not, shockingly, the shortest one!) and for roughness of gait, but the corrections that need to be made can be gauged by having all of the antenna-carryers walk the same path before going their separate ways.
We spent a full afternoon tromping around the catchment, and the four of us managed to cross paths only a couple of times, hopefully implying that we didn't all cover the same ground. In my run-in with one of the professors, I was detailed to walk around the far edge of the site that hadn't yet been covered. I did so, but then I proceeded to overshoot the other edge of the site and get quite confused. I continued to walk through all of the (mostly-dry) drainages I could find for a while, but I started to get worried when I wasn't catching sight of the base station or the precariously balanced rocks. I definitely realized the irony of not having a clue where I was, despite having a GPS antenna strapped to my back, but dark humor wasn't going to get me out of the situation on its own. I did manage to work my way back to the road, then proceeded to go the wrong way on it for about half a mile before I noticed that I was wrong. It turns out I'd found the road only about 200 yards shy of the turnoff that lead straight to the base station. Ah well!
I haven't seen our DEM yet, though I'm told we covered a lot of ground, and I'm told that there was one antenna that went quite a bit further away than all the others did. One of the people in the class is doing all the processing as his final project for said class, so I may ask him if I can show off the results of our day in the field.
Anyway, though much of my time this quarter has been spent at a desk, the seminar I'm taking on tectonic geomorphology and quaternary field methods has served well to get me out and about. Many of our "trips" have been into the hills behind campus, mostly for funding reasons, but we have had a few larger outings. The most intensive one so far was when we went to Grass Valley in the San Bernardino Mountains to make a digital elevation map using kinematic GPS. (There was also a USGS/Caltech team out there using LiDAR to image some precariously balanced rocks, but we did not get to actively participate in this part of the work; we were mere observers.)
Grass Valley is located in the San Bernardino Mountains, not far from Lake Arrowhead. It falls into the region of highest possible threat of major earthquake ground motion in the state, due to its proximity to several major faults. The San Andreas Fault is 11 kilometers away, with several well-constrained paleoseismic sites within 20 km. The San Jacinto Fault is only a kilometer or two further away than the San Andreas; the north frontal thrust of the San Bernardino Mountains is about the same distance away to the north. The Cleghorn Fault runs directly through Grass Valley, though its activity isn't as well constrained; there's no current microseismicity, and no evidence of Holocene rupture.
The precariously balanced rock team was clearly there to try and constrain whether or not the worst case scenario of shaking according to the state hazard report had actually ever happened since those rocks became precarious to begin with. The focus of the class exercise, however, was more on a catchment containing a small system of drainages in the process of being captured by the Mojave River. Our goal was to use kinematic GPS to get a good picture of the area, which could then be used to better situate the precariously balanced rocks in the middle of the site.
Kinematic GPS is a method of relative measurement. Actual latitude/longitude figures don't come into play. All measurements are taken relative to a base station that gets set up somewhere central in the site, for the express purpose of kinematic GPS measurement. People then carry portable GPS antennae, either attached to a backpack or on a long pole, all over the area surrounding the base station. The goal is to go back and forth over all of the bumps and dips in topography - even though that does, of course, make for harder hiking at times - to make sure they show up in the DEM. The data has to be corrected for height of the person carrying the antenna (I was not, shockingly, the shortest one!) and for roughness of gait, but the corrections that need to be made can be gauged by having all of the antenna-carryers walk the same path before going their separate ways.
We spent a full afternoon tromping around the catchment, and the four of us managed to cross paths only a couple of times, hopefully implying that we didn't all cover the same ground. In my run-in with one of the professors, I was detailed to walk around the far edge of the site that hadn't yet been covered. I did so, but then I proceeded to overshoot the other edge of the site and get quite confused. I continued to walk through all of the (mostly-dry) drainages I could find for a while, but I started to get worried when I wasn't catching sight of the base station or the precariously balanced rocks. I definitely realized the irony of not having a clue where I was, despite having a GPS antenna strapped to my back, but dark humor wasn't going to get me out of the situation on its own. I did manage to work my way back to the road, then proceeded to go the wrong way on it for about half a mile before I noticed that I was wrong. It turns out I'd found the road only about 200 yards shy of the turnoff that lead straight to the base station. Ah well!
I haven't seen our DEM yet, though I'm told we covered a lot of ground, and I'm told that there was one antenna that went quite a bit further away than all the others did. One of the people in the class is doing all the processing as his final project for said class, so I may ask him if I can show off the results of our day in the field.
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