The Trembling Earth

now at blogs.agu.org/tremblingearth

Category Archives: Uncategorized

The big move – Find me on AGU blogs!

AGUblogosphereBlack

Hello loyal followers: I have the great honor of announcing that the American Geophysical Union will now host my blog. AGU is a preeminent global society dedicated to supporting, disseminating, and advancing Earth science. They run a number of the most prominent Earth science academic journals and annually host–among a number of smaller regional conferences–the largest Earth science conference on the planet. As part of their outreach efforts they have assembled the AGU blogosphere, a group of passionate science bloggers with the itch and ability to discuss science, from how it’s done to what it shows to how it relates to you and the rest of the world. It is with honor that I join their ranks, and look forward to the opportunity to share my passion for things seismological through an outlet that will open the discussion to scientific and public audiences alike.

The new URL is http://blogs.agu.org/tremblingearth and all of my posts have been migrated there!

Find me on AGU blogs!

Advertisements

Yakko, Wakko, and Dot recount the Northridge quake

“It’s just the planet moving granite several city blocks.”

Our favorite cat/monkey/dogs reflect on their experience of L.A.’s 1994 temblor. Of course the Warner Brothers studios–where the writers work and the Animaniacs themselves live–is situated in the heart of Burbank, where shaking from the Northridge earthquake (on January 17, 1994, at 4:30 in the morning) was severe. In the early 90s L.A. truly established itself as the city of disaster by heaping mudslides upon fires upon riots upon disastrous quakes. But heck… we’re Californians.

…and just for all our records, and because they’re just so clever, here are the lyrics:

Animaniacs – A Quake! A Quake!

This is the city: Los Angeles, California

On a starlit winter night
When the moon was shining bright
Back in January of 1994 …
At 4:30 in the morning
And without a single warning
Something strange began to move the floor.

A quake! A quake!
The house begins to shake!
You’re bouncing ‘cross the floor and watching all your dishes break.

You’re sleeping, there’s a quake;
You’re instantly awake!
You’re leaping out of bed and shouting, “Oh for Heaven’s sake!”

I ran outside with neighbors
Their faces filled with shock
That’s because I’m standing there in NOTHING BUT MY SOCKS!

Oh a quake, a quake,
Say it’s all a big mistake!
Just feel the ground go up and down / Won’t someone hit the brake?

A quake, a quake!
Oh what a mess they make!
The bricks, the walls, the chimney falls / destruction in its wake.

I did not have insurance
So I called them from the scene
And suddenly I’m list’ning to an answering machine /
Say, ‘too late, too late!
You shouldn’t ought’a wait,
‘Cuz now you’re stuck, we wish you luck, here comes a six point eight.’

Whose fault? Whose fault?
The San Andreas’ fault.
Cuz Mister Richter can’t predict her / kicking our ass fault!

Seismologists all say tectonic plates are in between
An encroaching crust and mantle,
Yeah so what the heck’s that mean?!

It means a quake! A quake!
Oh really, yeah, no fake?
We kind of had that feeling when the ground began to shake….

California’s great!
It’s such a lovely state.
And every lawn is sitting on a continental plate.

Los Angeles had fires
And a riot and a flood
And then a drought and a recession and then now we hear this thud
Of a quake, a quake
How much more can we take?
We thought that we had seen it all but this one takes the cake.
The dirt. The rocks.
And all those aftershocks.
It’s just the planet moving granite several city blocks.

L.A. town is falling down
while the ground / moves around
We won’t let us get it down
We’re Californians.

A quake, a quake.
It’s time to pull up stake.
We’re all fed up we can’t deny it
Fires, quakes, and floods, and riots,
We want some place with peace and quieeeeeet…

So we’re moving to Beirut!

Follow me @TTremblingEarth

evolvetoTweetI’ve done it: I’ve taken the plunge into the Twittersphere. Tweet-a-sphere? Twit-osphere? Well anyway I plan to use Twitter to send out all the glorious little things I find neat and interesting and have nowhere near enough time to blog about, or which don’t really warrant a whole bunch of additional talk, like this and this and this (ew) and this (oh please at least click that last one).

My Twitter handle is TTremblingEarth, whose first ‘T’ you can view as either a contracted “The” or an appropriately tremulous stammer, but which was actually just necessary because apparently Trembling Earth is a band performing “psychedelic Americana, blues, and rock’n’roll from the swamps of Southern Georgia.” That sounds awesome actually.

So there you have it. If you’re on Twitter, you can find me doling out earthquakey tidbits there, whereas I’ll keep using the blog for material that merits a little more backstory. I think I’ll try to blog a weekly recap of my Twitter posts so those of you avoiding the service don’t have to totally miss out like you’re trying to. It seems to be a nice model for the fellows at Highly Allochthonous and Paleoseismicity, so–substantial overlap with them aside–I’ll do it too.

Trembling Ice: The largest glacier you’ve ever seen collapse

An iceberg calves off of Ilulissat glacier in Greenland. Photo credit: Martin Truffer/University of Alaska-Fairbanks

Straying briefly into the hydrosphere, I’d like to bring to your attention a video of an event that no doubt trembled the Earth for miles around, and wrought seismic and tectonic havoc on the Ilulissat glacier in Greenland.

In the course of capturing footage and ice-cap scenes for their new and acclaimed movie “Chasing Ice“, a team of young sciency filmmakers/photographers witnessed the most enormous collapse of a glacier ever recorded on video. And they had dozens of cameras rolling. It just doesn’t get better than this.

The scale of what unfolds in this video is simply incredible, and I will be booking my ticket to go see this film as soon as possible.

I could go on marveling at the sheer scale and scope and sound and sight of the ice breaking up, but the video speaks for itself, so I’ll stop here and let you all go admire. Keep in mind two things: ice is less dense than water (more buoyant), but only just enough that a mere 10% of an icy mass rises above the liquid water it floats in. Secondly… you’ve never seen anything like this, at least outside of Spielberg.

(High-definition version at link below)

Head over to The Guardian to watch the original high-def clip and enjoy. I know I did. Over and over.

Chasing Ice movie reveals largest iceberg break-up ever filmed – Guardian UK

Field work: Accomplished

I’m back! …from my fourth and “final” field season in western China. I spent a month on the northern edge of the Tibetan Plateau, hunting around in the dirt for evidence of past earthquake ruptures. Fortunately the Altyn Tagh fault is a pretty big deal, so there’s plenty of geologic history to scrape out of it.

Scrapin’ the history out of the Altyn Tagh

Theoretically I’ve collected all the maps, surveys, geochron samples, and frantically scribbled thoughts about fault dynamics that I need to successfully complete this PhD, and that wouldn’t have been possible without the generous collaboration of colleagues at the China Earthquake Administration and its local branches, in particular this year Shao Yanxiu who was an essential pair of extra field hands and was pretty clutch at handling logistics too.

Shao Yanxiu stands at the edge of the Tarim basin, where the Tibetan Plateau slides past to the left, along the Altyn Tagh fault, which runs straight up the center of the image before kinking rightward in front of that icy peak.

So, acknowledgements out of the way, I’ll get to the nitty gritty of my field work and the sorts of things I see/saw/hope to understand, in another post. There may also be some [post-]travelogue-ing. For now: I’m back, and hopefully I’ll settle into a more regular pattern of posts. There are plenty of topics I’ve been dying to scribble about, but preparation for [and] a month in China has pushed the blog to a back burner. More quake stuff, coming right up!

Trembling from above – first-hand tornado wrath

This past weekend The New Yorker‘s new “Weekend Reading” feature directed me to a fascinating disaster survival narrative that was so good I figure I can take a little departure from solid Earth phenomena to point you all to the enthralling account… and the first-hand videos that accompany it.

The path of the May 22, 2011 EF-5 tornado that tore through Joplin, Missouri. The tornado scored a direct strike on the city’s hospital and high school, and ravaged neighborhoods in between. The New York Times has an interactive feature with before-and-after imagery: http://www.nytimes.com/interactive/2011/05/25/us/joplin-aerial.html

The disaster in question was an EF-5 tornado that scored a direct hit on the modest southwest Missouri town of Joplin on May 22, 2011. In one of those extremely rare and extremely unlucky coincidences, the massive tornado formed right on the western outskirts of town and plowed its 3/4-mile-wide way through the heart of the 175,000-person city, lightening up and lifting off only once it reached the eastern edge of town. The path of the twister could scarcely have been worse: the strongest winds were sustained for a 6-mile path that coincided nearly exactly with the extent of the city, and its trajectory took it directly across the hospital, the high school, a middle school, several large retail complexes, and countless residential neighborhoods, all with wind speeds approaching or exceeding 200 mph.

Power went out throughout the city early in the event, as increasingly frantic newscasters on TV and radio tried to supplement the city’s 3-minute-long siren warnings to convey the dire danger of this particular storm. Naturally, many residents, having been through big midwestern storms before, did not expect what was to come. In the videos that exist of the event (there are surprisingly many), most people do not take shelter until the monstrous tornado is directly upon them, revealing some level of optimism–or at least disbelief–at what was unfolding.

The eye-witness accounts of the tornado are gut-wrenching. In one particularly remarkable video, a group of strangers has gathered in a convenience store on the eastern edge of town. They’re all there for different reasons, although they’ve been driven inside to take shelter from the storm. As they gradually realize the gravity of the situation, they have no clue that this huge looming tornado has already done most of its damage to their southwest, literally ripping their city to shreds. They also don’t–and couldn’t possibly–know what is about to hit them. It is their stories that are compiled in the captivating article in–of all places–Esquire. The article is so well written that you’ll think you’re among the survivors, huddling together and fearing for your life. It also links to that infamous gas station video, which is fairly emotionally strenuous. I’ve never watched anything so tense; Hollywood eat your heart out.

These links should take you through the event, starting with the article:

“Heavenly Father!” “I love you all!” “I love everyone!” “Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus! Jesus!” “I love all of you!”

And here–hold on to your seats–is the video:

The videographer who captured that emotionally draining scene went back the next day to revisit the site that brought them all together in what they thought was their moment of death. Here’s what the place looked like:

Because the destruction is entirely wrought in the deep dark of the tornado, a different video may illuminate the unbelievable winds that defined it:

Joplin tornado recorded by home security camera (youtube)

There are a few additional home videos of the tornado tearing through the neighborhoods, and although the videographers survive in safe interior rooms or basements, these intense clips may be difficult to watch, especially considering the immense loss these people faced upon emerging from their shelters:

Here a family hides as the approaching roar (“That sounds like a train. Is that the tornado??”) and pitch black of the tornado itself descend upon their house. Definitely grab your headphones/good speakers for this one.

http://youtu.be/fo81EQN98Oo

Here’s another family at home… in this one the people’s terror is pretty vicariously horrifying:

http://youtu.be/bZvo39XT8bk

In both of those, the sound of the tornado–that concentrated zone of 200-mph winds tearing its way toward the camera–is quite remarkable.

Then there’s a group of tornado chase tourists who get more than they bargained for. Their panic is evident as they realize the gravity of the situation… and ultimately they can hardly outrun it.

http://youtu.be/CburjPYmSdo

I encourage you to learn more about the humbling event itself, at NOAA’s info page about it:

http://www.crh.noaa.gov/sgf/?n=event_2011may22_survey

…and to keep this experience in mind when the sirens go off in your midwestern town. In the case of tornadoes, we have the technology for advance warning… don’t squander it, and don’t take it for granted!

Musings on seismology and earthquake hazard

A seismogram of the M6.8 “Nisqually” earthquake that struck central Washington state in 2001.

Phew, I’ve been a neglectful blogger… probably to the benefit of my dissertation research. I’ve got a few interesting posts in the pipeline, so I think I’ll take what time I can to finish them, then set them up so they’re nice and distributed for you to read.

In the meantime, you should all check out two cool blogs maintained by earthquake aficionado Arne Christensen, in which he compiles media and eyewitness accounts from two of the U.S.’s most notable contemporary earthquakes: Loma Prieta and Nisqually.

Arne recently asked me a few pressing questions he had about seismology and seismic risk on the U.S. west coast. The questions were very provocative and very relevant, so I crafted some responses that were as informative as I could make them without stepping on anyone’s toes. They’re good distillations of my thoughts on earthquakes, and I’ll vouch for my own synopsis of current earthquake research (although I advise anyone seeking formal advice to seek more direct sources, like the USGS, the Pacific Northwest Seismic Network, and contributing researchers). Caveats and citations aside, I think you should all go have a read of my “interview” for my personal take on modern seismic hazard “hot topics,” then you should peruse the wealth of accounts Arne has collected of recent significant quakes.

Part 1: Living with Earthquakes on the West Coast

http://nisquallyquake.wordpress.com/2012/04/27/living-with-earthquakes-on-the-west-coast/

Part 2: Seismology Issues and Changes in the State of the Art

http://nisquallyquake.wordpress.com/2012/04/29/the-work-of-seismology-explaining-a-few-issues-and-changes-in-the-state-of-the-art/

I welcome any discussion of the points I made, and any corrections by more credible seismologists than myself.

Reblog (not mine): Pete Rowley of “Lithics” writes about the M8.6 near Sumatra

I’ve got tons of stuff I should be doing, but I can’t resist the allure of discussion of the fascinating pair of earthquakes that happened last night in the Indian Ocean. I don’t have much of anything to add to the existing discussion, and I need to, like, get to work, so this is a “reblog” of the most thorough description I’ve seen of the setting of these quakes, by Pete Rowley on his “Lithics” blog. Note that there were two, both were massive (8.6 and 8.2), and they had a “foreshock” on January 10–sameish place, similar focal mechanism. Both of these are larger than any strike-slip earthquake we’ve recorded before, and the larger one makes it into the top 10 list of all time in any setting. It’s additionally fascinating (read: perplexing, at the moment) that they happened in oceanic crust, which is generally considered too thin to support massive strike-slip earthquakes. This will be an absolutely fascinating earthquake sequence to learn from in the coming hours, days, and weeks.

lithics

Earlier I posted an info bulletin about this morning’s Banda Aceh earthquake.  Rather than muddle it with more and more stuff, I thought it might be better to include this update as a separate post, as it is more of a discussion than a news piece in any case.

The truth is that this earthquake is properly strange.

The part of the Indian Ocean in which this earthquake occurred has two very different types of geologic structure very close to each other; there is the Ninetyeast ridge – a volcanically produced range,  and a destructive margin subducting the Indian plate eastwards under the Pacific margin. It is important to note (in the context of this earthquake at least) that the sea floor under the Ninetyeast ridge was originally produced by standard constructive margin seafloor spreading.

These two structures are shown quite nicely in this image taken from GeoMapApp, with…

View original post 812 more words

Earthquake photo mash-ups

San Francisco-based photographer Shawn Clover came up with a creative project: not only did he re-create classic photos of the 1906 earthquake’s destruction from the same vantage points as the original shots, but he’s blended the old and new together in surreal, oddly amusing, and moderately alarming photo stitches.

"Two girls stand before the partially destroyed Sharon Building in Golden Gate Park while students work on their art projects inside." Photograph blend by Shawn Clover. More can be found at http://shawnclover.com/2010/10/01/1906-2010-the-quake-blend-part-i/

From the photographer’s website:

Where was the exact spot the photographer stood? What was the equivalent focal length of his camera’s lens combined with the film medium? How high off the ground was the camera? Where was the sun in the sky? Everything needs to be precise when layering two photos on top of each other.

Have a look at the whole collection:

Shawn Clover – The Earthquake Blend

The fascinating perspectives capturing the destroyed “then” and the recovered “now” would make a superb earthquake awareness campaign, don’t you think?

AGU – largest Earth Science conference in the world

The AGU Fall Meeting is finally suddenly here! The American Geophysical Union annual meeting is the most widely attended Earth Science conference in the world, and many of us will be showing up there this week to share our work, talk to colleagues, and catch up with old friends from all stages of our geophysical careers.

I’ll be truckin’ down the road from Davis to the convention center in San Francisco to present my own work on topographic change detection following the El Mayor-Cucapah earthquake. I look forward to the overwhelming onslaught of science discussion, but I’m also quite excited about the opportunity to socialize with Earth science friends old and new in one of my favorite cities.

I’ll see some of you there, but for those of you who won’t be making it, or who want a sneak peek of my own poster, here it is in all its glory. I’ll be standing by it to give the spiel on Wednesday morning 12/7 in the Tectonophysics session T31B: “New Constraints on Active Fault Zones,” poster 2341. I’m also coauthor on a companion poster in the same session, #2352, in which UCD grad Peter Gold documents uncertainty analysis in slip distributions provided by the same ground-based LiDAR scans. You can check out either of the posters in person, or click the link below to see them on our UCD LiDAR lab webpage.

My 2011 AGU poster, showing terrestrial LiDAR detected elevation changes in the year following the M7.2 Cucapah earthquake

My adviser is also giving what should be (IMHO) a very compelling talk Wednesday afternoon, regarding more LiDAR topographic change detection, this time between pre- and post-earthquake airborne topographic LiDAR surveys. 4:00 12/7 in 2016 Moscone West. I’ll be there!

See you at the conference! Full report to come.

%d bloggers like this: