Thursday, July 15, 2010

A Serpentine-Inspired Rant

By this point, I don't think I need to actually outline the whole fiasco surrounding the motion to demote serpentine from its position as California's state rock. More prompt geobloggers than I have already outlined this idiocy - seriously, unless you're inhaling serpentine dust like it's oxygen, you're not going to run into an asbestos problem - and those posts (and the flurry of commentary from geotweeters) have reached the attention of national media.

The claim that serpentine is an "unhealthy" rock is ridiculous on its own, but you know what else strikes me as ridiculous about this whole issue? The fact that, suddenly, people are getting all freaked out by the mere idea that something about California's geology might be able to kill them.

Hold the phone! Stop the presses! California's geology may be hazardous to your health and wellbeing?!

This is a state sliced by a plate boundary, with the main fault and all of its subsidiary ones capable of city-destroying earthquakes. We're known for our earthquakes, are we not? This is a state where the configuration of mountains focuses, heats, and speeds up the wind like a huge bellows, and effectively creates corridors of fire. We're known for our fires, are we not? This is a state where steep slopes produce debris flows after storms or slump off after longer rains. We're known for our landslides, are we not? Not to mention the contours of the coastline that serve to magnify distant tsunamis in some cases, or the ski resorts that happen to be dormant volcanoes...

I would say those things can be pretty darn hazardous to your health. I suspect that plenty of people would agree with me: the residents of La Conchita, of Crescent City, or of Sylmar, the historians and current residents of San Francisco, those who visit and monitor Mammoth Mountain, just to name a few. I'd hazard a guess (rimshot) that these folks would find those geological threats far more pressing than some specific minerals that are one component in a rock that's more commonly found underground than in, oh, our lungs. And I suspect the other geologists pushing to keep serpentine as California's state rock would agree with me as well.

So, California's geology can be pretty darn unhealthy, for values of unhealthy ranging from "deadly due to fault surface rupture collapsing one's house on oneself" to "alive but breathing in lots of smoke." But California kind of represents us as Californians, doesn't it? Does that mean the next step is to demote California's entire landscape from representing the state?

That would be ridiculous. But isn't it, then, ridiculous to make a fuss about demoting a rock that is really only dangerous if someone throws it at you, or perhaps if you drive off a cliff with a serpentine outcrop at its base? (Because, in case you somehow missed the other blog entries, tweets, and news articles, serpentine isn't going to give you cancer!)

Aside from all that, the formation of serpentine is directly related to the forces that formed and shaped so much of California to begin with. As such, it's an excellent representative of the state. (And for any politician who knows the word "subduction" and is about to claim it's dangerous for causing quakes and volcanoes, the serpentine is a byproduct of that process, not a cause. If I wanted to be even snarkier than I already have been, I could argue that picking a rock that is dangerous might better represent California's potentially-hazardous landscape. Be glad serpentine is "just" a representative of how the land that became our state got here to begin with. Also, be glad that it's pretty. Can you find me a prettier rock that also represents California well?)

I think that's quite enough from me, at least for now. I'll leave with this note: why is state money getting spent on this issue at all? If California wants to spend money on reducing geologically-induced harm, that money would be better spent on things like seismic retrofits, zoning to avoid earthquake and landslide hazards, clearing brush between the urban-wildland interface to try and avoid fires spreading into neighborhoods, emergency response training for civilians, and general awareness and outreach.

Friday, June 18, 2010


Hello, Geoblogosphere!

I realize I should have posted a more formal hiatus in advance of all of this, but at the same time, I didn't realize I'd be quite this insanely busy.
Which is, I also realize, a ridiculous assumption, given that I was working on my Master's thesis this quarter.

That said, I am finished with it! I defended the thesis on Tuesday, to a surprisingly large audience given that it's technically summer break now. I made the minor revisions, and I officially filed the thesis with the graduate division this afternoon.

I am staying at the same school to do PhD work, and that work will be a direct offshoot of my MS work. In terms of the actual work, there's not a big cutoff or different direction, and I'm still really excited about the work I'm going to be doing next. Even with the direct continuation, there's a definite sense of accomplishment: that I wouldn't be continuing into this third (and fourth and fifth and...) year of work if I hadn't finished the Master's stuff first! So, here's to the last two years, and the next three!

The first big thing I'll be doing as a person who actually has a degree in earth science is going to a a castle in Slovakia. Seriously. It's a conference specifically on numerical modeling of earthquake dynamics, and my adviser and his other student are also attending. I will be giving a talk on my latest work. I will try to be less of a flake about blogging this than I have about the other conferences at which I gave talks.

After that, I'll be heading up to the Bay Area for July, August, and September to help with some laboratory experiments on fault friction at USGS. Needless to say, I'm beyond merely excited about this opportunity!

Another thing I really hope to do this summer is put up a series of posts on Things I Should Have Blogged About Months Ago. Because I'll be the first to say that I'm behind on this! Topics I plan on addressing are:
The trip to Hawai'i (This was in October of 2009, I am such a slacker.)
The rest of AGU (or, at least, how my talk went)
The Rise and Fall of Snow Los Angeles (purely silly, but to be blamed on a conversation at AGU)
The earthquake in Mexico, and going into the field immediately afterward!
Seismological Society of America conference in Portland
Visiting Mt. St. Helens

And I hope to be more on the ball about the Accretionary Wedge as well.

Friday, March 26, 2010

Accretionary Wedge #23: The Thing That Eats My Time

Hello, world! I realize I've failed at the day-to-day writeup of AGU that I promised back in December (eep), but what better way to come back from an unannounced work-induced hiatus than to describe the work I've been doing, hm?

I don't think I've blogged much about the research I do. I know I post about about interesting places I visit, visible and tangible fault features, and outreach, but my actual research doesn't have a field component yet at all. I do work in earthquake dynamics - the physics of how faults rupture. My method so far has been numerical modeling, specifically with both 2d and 3d finite element codes. This method divides both sides of the fault into a grid of elements of a designated size, then applies equations of motion, stress transfer, and wave propagation to each element over each timestep, then sums up the result. Each model represents a single earthquake on a fault; aside from a forced nucleation point, the magnitude and intensity of the quake are determined by the model parameters. There are many existing codes that do this, and I've been working with two of the newer ones. I've also very recently started doing some multi-cycle quasi-dynamic models. These take a fault system and put it through multiple earthquake cycles, including interseismic application of tectonic stresses. What makes them quasi-dynamic is the ruptures work by way of stress state, and don't include dynamic wave propagation.

There are a lot of fault parameters you can tweak in dynamic models, and my work focuses on the effects of fault geometry on rupture behavior and ground motion. Models investigating other parameters might use a fault that's a straight line, but straight lines almost never happen in nature. Faults have branches, bends, discontinuities, and stepovers, and they've proven to be important factors in determining where earthquake rupture stops. There's one field study of mapped surface ruptures (Wesnousky, 2008) that shows that a significant number of surface ruptures die out near a geometrical discontinuity in the mapped fault trace. On the other hand, events like the 1992 Landers earthquake or the 2002 Denali earthquake show that rupture can traverse some considerable discontinuities between faults. Understanding how rupture behaves when it encounters a geometrical discontinuity is therefore very important in determining the hazard associated with individual faults or fault systems.

I already have one fault geometry paper (which also happens to be the first chapter of my Master's thesis) in review. It's a parameter study of whether or not rupture will propagate through a bend in a fault of a given length, with a given connecting angle. Unsurprisingly, steeper angles and longer bends are more likely to halt a rupture, but exactly how steep or long varies depending on whether the step is extensional or compressional (that is, whether the bent segment is pulled apart by the fault's direction of slip, or whether it's crunched together), on the overall size of the fault system, and on the orientation of the stress field acting on the fault. That third criterion is particularly important - in some orientation, dynamic effects control the rupture far more than static ones, but in others, static effects can overcome dynamic ones. I still haven't heard from any reviewers on this paper, but I'm sure I'll post here excitedly when it goes into press.

I'm working on a second paper now, determining how fault geometry affects the intensity and distribution of peak ground motion in an earthquake. In this case, I'm using fault systems that consist of two segments with no linking segment, meaning that rupture has to re-nucleate on the second segment as opposed to just traversing an unfavorable part. I'm looking at both compressional and extensional systems here, with a varied distance between the fault segments, a variety of stress drops, a variety of rupture velocities, and a variety of different rock types. So far, I'm finding that every single one of those parameters affects the pattern and intensity of motion. The talk I gave at AGU (which I will write about, really!) was about preliminary results of this work, and I'll be giving a talk at the Seismological Society of America meeting in Portland in April about the specifics of the material contrast cases.

So that's my research - as I transition into working on a PhD, I'll start investigating more complex geometries and looking at real fault systems, as opposed to hypothetical ones. All that while still taking a bunch of classes to catch up on my background!

Thursday, December 17, 2009

AGU 2009, Day Three

The entire afternoon on Wednesday was filled with talks directly related to the type of problems I look at and the type of modeling I do - a pretty sharp contrast with Tuesday! The morning, however, was fortunately open for such things as practicing my talk one more time for my adviser, and for meeting with SCEC's education and outreach team about "Faults of Calfornia."

The practice run went smoothly. I presented preliminary results of the same work at the SCEC meeting in September (and then I had to do all the models over because we switched finite element codes), and I did a couple of practices of the talk at UCR over the past few weeks. My biggest concern was timing, since my first practice clocked in at 13.5 minutes without questions, but my second practice went at Mach 1, taking only 9 minutes. Yesterday's practice was a clean 12 minutes, and I haven't had any more coffee than usual this morning, so my timing should remain spot-on.

The meeting with SCEC was also productive. Our main goal right now, since the illustrations on "Faults of California" are all done, is to figure out the best way to get it into schools. We don't want to just hand it to teachers without any structure, since that's not the best way to integrate into anyone's lesson plans. We came up with a few ideas; my holiday reading is likely going to involve reading some of the California Education Standards, and it looks like there will be some drives to USC in early 2010.

As some of you reading this surely already know (since I assume at least some of you were there), there was a planned lunch for geobloggers at AGU yesterday afternoon. I'd say there were about 25 of us in all. The first half was more informal conversation - it was nice, as with the Tweetup on Monday, to put faces to names and blogs. (And, in the case of those of you I'd met before, it was great to see you all again!) The second half of the lunch involved everyone getting up and introducing themselves and their blogs, then sharing their particular thoughts on the state of the geoblogosphere. I'll repeat a thought I had at the time: I think it's wonderful that so many of us started blogging because we just plain like discussing our field and research, and that this network of blogs has turned into a real and more formal way to exchange information and dialogue in the sciences.

I had to duck out of the blogger lunch a bit early because I didn't want to miss the set of talks on earthquake source modeling. Occasionally, I have a moment of worry that someone will scoop the particular things I want to research/model - because there can't be that many people modeling fault dynamics, right? - but sessions like this make me realize that I'm being dumb for worrying so much. There's a huge diversity of topics, methods, specific problems, and ways to interpret within the definition of "earthquake source modeling," and even in four hours of talks, there's still tons and tons more that hasn't been covered or done yet. One of the main themes in this session was the idea that multiple faults can be involved in a single earthquake. This has been known at least since the M7.3 Landers earthquake in 1992, which surface ruptured its way through parts of six faults, but many of yesterday's talks discussed the possibility of there being subsidiary faults in quakes not known to have involved more than one fault, or the possible contribution of smaller faults to a quake on a much larger one. With all these discussions, I feel like I've come into looking at the problem of fault geometries and interactions at just the right time, and that makes me all the more excited to keep on modeling things.

My talk is also a complex fault geometry talk, though in this case, I'm looking into geometrical effects on ground motion, rather than just on rupture behavior. It's this morning (Thursday, 17 December) at 11:05 AM in Moscone West room 2005. I hope to see some of you there!

Wednesday, December 16, 2009

AGU 2009, Day Two

There are always a gajillion different things going on at AGU, to the point where it's overwhelming to consider all of it. When I considered the categories that are most likely to relate to my work (Seismology and Tectonophysics, also sometimes Union), Tuesday seemed to be the day that had the least subject matter related to my own work. That made it a logical day to catch up with people and discuss projects and research - not to mention, it was a good day to do my stint as the representative at the UCR booth in the exhibition hall.

The first thing I did was head over to the Southern California Earthquake Center booth to set up a time to discuss a project I've been working on with them. I know I've mentioned this project rather evasively thus far, and while I can't give lots and lots of details yet because it hasn't been released yet, I will say that it's an earthquake awareness comic book called "Faults of California." The illustrations were finished this summer, but we're working on a education module to go with it. We ended up deciding to meet about this on Wednesday, but I stuck around the booth to help set up. This involved a scene of several people jumping up and down while shaking a poster tube, trying to dislodge a bunch of plate tectonics educational posters. Brings new meaning to the idea of "ShakeOut"!

I did go to a late morning session on earthquake early warning systems. Most of them were variations on the theme of using P-wave amplitude to make a guess at eventual magnitude, though they all suggested different ways to implement this. One took the approach of tracking sudden motions by GPS and reporting them that way (though, from talking to people at UCR who work with GPS, I would think this would take a while to process?). Another aimed to estimate the direction and extent of the eventual rupture by looking at wave directivity. This one was particularly interesting to me in that I think it would benefit from some sort of prior including possible rupture paths for faults with complex geometry. I hadn't ever thought that the kind of models I do could help with early warning, but apparently they could! The early warning session also included a talk on the Quake-Catcher Network, which I've blogged about on here before. This network uses the accelerometers built into laptop computers as basic earthquake ground motion sensors, and sends the timing and shaking data to a central network for consideration. When I first installed the software in early 2008, QCN was still in alpha-test mode. It currently has expanded to over a thousand users across the globe. (And I'd encourage you all to check it out and add to the member count!)

I spent the entire afternoon at the UCR booth in the Academic Showcase part of the exhibit hall. Traffic was relatively slow to the booth (and it probably didn't help that we were between Yale and Virginia Tech), but there were a few prospective students who signed the mailing list. I also got a lot of questions more pertinent to the Environmental Sciences department (which is not the same as the Earth Sciences department at UCR), and a lot of inquiries about "Where is Riverside, anyway?" (when I answered that one, it was often followed by, "Wow, is it really hot?"). I assure you, visitors and questioners, that our department is worth another look. Being in the desert and 100+ degree heat does nothing to hinder the good work coming out of UCR.

Tuesday, December 15, 2009

AGU 2009, Day One

So! I'm going to attempt what, given my past history with regular updating, may seem like a futile effort. That is, I'm going to try and blog every day of this year's American Geophysical Union Fall Meeting (in San Francisco, as usual) separately. This is just as much a way to not gloss over things as it is a way to try and practice general better blogging habits. This meeting has already stressed the importance of blogs for communication, and the possibilities of using Twitter both for spreading and collecting information about various geological/enviromental/hazard/etc. events. I've certainly been tweeting a lot lately, but my blog is now saying, "Don't leave me for that biiiird!" And so, daily entries for the conference. Yes.
(I'll also be dumping a day-by-day of the class trip to Kīlauea in here soon - possibly later today, if the UCR booth in the exhibitor hall has low traffic.)

The very first talk of the very first Tectonophysics section yesterday was one I really wanted to go to. It involved the formation of the San Andreas Fault, with comparisons to the transform boundary in New Zealand. Alarm clock failure (in that, it did not go off) prevented me from attending, but I was able to get going quickly enough that I made it in to the middle of the second talk of the session (about a possible shift of the North American-Pacific plate boundary to the eastern side of the Sierra Nevada). The whole morning in the Tectonophysics group was devoted to continental transform boundaries, in fact. Most of these talks were focused on characterizing these boundaries, whether by classical mapping, looking at seismicity or paleoseismic data, or studying (very very shiny awesome) LiDAR images. There was a definite focus on geometry at several scales - map, or fault surface roughness, or shape of the damage zone. There was not, however, much talk of earthquake behavior on these systems, but thatʻs the divide between this group and the Seismology one, I suppose! I opted to listen to as many of the continental transform talks as I could, since my work is all about looking at rupture dynamics and ground motion on faults with geometrical complexities, and thereʻs a good chance that Iʻll be looking at the constraints on fault structure and geometry that researchers in the Tectonophysics group in constructing dynamic models sometime in the future.
(I was, however, slightly disappointed, that the Garlock talk basically led to the conclusion that "everyone still has completely different ideas of how much this thing is slipping." Ah well!)

After lunch (and after inflicting Hawaiʻi photos on a friend from Berkeley), I headed into the poster hall to get a look at as many more things about geometrically-complex strike-slip faults as I could. I got in some skimming before coming to a poster about segmentation and postseismic stress state in the Landers earthquake. I ended up getting into a great and detailed conversation with the poster-presenter, and before I knew it, it was time to go to another session.

The last session I went to was completely out of my area of more than scant knowledge, but at the same time, it was something that has interested me since I was ten years old. The session in question was a planetary science one, discussing this summerʻs Jupiter impact. The session was under embargo, so I wonʻt go into anything about what was actually said (other than the fact that Jupiter is apparently, quote, "insidious" about not showing features under certain filters), but it sent me back to that place of ten-year-old wonder when Shoemaker-Levy 9 slammed into Jupiter in 1994. That impact entirely captivated me, to the point where I was making an attempt to understand NASA press releases, contacting discoverers of the comet by email (seriously), and making my parents take me to a Smithsonian press conference about the impact. Iʻm not really sure I know much more about comets now than I did at the peak of my astronomy obsession, and Iʻm sure I was more timid about asking questions yesterday than I would have been in 1995, but I still thoroughly enjoyed hearing everything that the presenters had to share about this new impact.

The evening was occupied by a meetup of Geonerds On Twitter at 21st Amendment on 2nd Street. I had no idea what to expect in terms of attendance or formality of discussion, but there was a huge turnout and a very fun casual air about the whole thing. It was absolutely great to put faces to the names Iʻve been interacting with online for so long, and it was just as awesome to get to have incredibly unabashedly nerdy conversations with people that didnʻt end up getting bored with said unabashed nerdiness. Topics included the difference between astrophysics and planetary geology, when the best time to visit the Mojave is, how close we all live to various active faults, fuzzy animals, beer, and the usefulness of Twitter and blogs in conveying geogeekery across the internet and world. Iʻm hoping thereʻll be events like this one at future conferences! (Or, if thereʻs another one in San Francisco not during a conference, it gives me another excuse to come up here again...)

Thereʻs a luncheon for geobloggers on Wednesday. How many of you will be there?

Saturday, October 17, 2009

San Francisco, October 17th, 5:04 PM

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.