Geology Lessons

The enormous, near-apocalyptic temblor off the coast of Honshu would have been surprisingly tame, had it not been for the tsunami. The main reason for the comparative lack of architectural damage from the earthquake itself has to do with lessons the Japanese had learned well from history.

The great Tokyo earthquake of 1923 nearly flattened the city, with a notable exception to the general devastation: Frank Lloyd Wright's Imperial Hotel. It stood intact, surrounded by the debris of neighboring structures.

Since 1995's Great Hanshin earthquake in Kobe, the Japanese have implemented building codes and disaster plans designed to mitigate the inevitable destruction associated with the different kinds of earthquakes to which Japan is subject. The Kobe quake took place near a large population center, under the island itself, rather than offshore, so it didn't have to cope with a tsunami. Still, it wasn't as prepared as it could have been, and the human and economic impact was immense.

This week's quake was different, and the map below indicates why. It occurred along a subduction zone in relatively shallow water, not far from the coast: a recipe for large-scale tsunami impact. The numerous aftershocks haven't helped. I counted over 30 of magnitude 6 or higher on my iPad earthquake app--so many, in fact, that the big one had already dropped off the list. The pushpins on the map formed a huge, solid blob because the graphics weren't designed to depict hundreds of earthquakes. The map below is clearer, and if you click on it and then enlarge it, you can really see the enormity of an event that really hasn't stopped yet.

Having lived in four major earthquake zones (Japan, Taiwan, the Owens River Valley, and southern California), I'm no stranger to the earthquake experience. Even when small ones occur in unlikely places (such as Pennsylvania and Dallas), I sense them early and seem like a prophet to those around me (or a complete nut; take your pick). My interest in geology may, in fact, have stemmed from wondering about what caused it all.

But the aftermaths are also indicative of how human beings respond to disasters when they live in areas prone to them. There are few places on the planet that aren't subject to some dangerous phenomenon or other. Here in North Texas, we're on the lower fringe of Tornado Alley (which seems to be widening as the climate changes), and always teetering on the brink of drought. Hurricanes, floods, katabatic winds, wildfires, avalanches, and all manner of catastrophic events occur in places that might be safe from earthquakes, volcanoes, and tsunamis--although many are located within areas with a wide variety of potential natural disasters to withstand.

How we live when faced with these consequences is where clear-thinking and lessons from history should prevail when making choices. Sometimes what seems to be a good idea at the time turns out to be problematic, as with Japan's increasing reliance on nuclear power. In order to reduce its dependence on oil, the country has chosen to bet on nukes. Now, to me this sounds absolutely crackers, given the location of the island: at the edge of a plate boundary subject to ten centimeters of movement in a year. Sure enough, the Guardian is reporting today that the Japanese nuclear industry has barely dodged a bullet at the Fukushima Daiichi nuclear reactor, and avoided a meltdown. At least for the time being.

In 1872, what may have been California's worst earthquake in recorded history (around the same magnitude as the one in San Francisco in 1906) occurred along the fault line over which I was born. The valley's population then only numbered about 300, and twenty seven of them died. They're buried in a monument just outside of town. The land slipped down on the eastern segment of the fault, all the way up to Big Pine. On one of my last trips there before my father died, he pointed out the spot on the family's old property where a spring opened up as a result of the quake. (I love the lurid headlines at left; a sign of things to come in the Murdock era of tabloid journalism.)

The adobe structure in the center crumbled, leaving only its roof.

The frame house survived intact, losing only the flimsy shed attached.

The lesson from this rather small-scale local event (when compared, at least, with what Japan is going through today) was that adobe houses don't withstand earthquakes; only the frame houses survived. From then on, frame-built buildings took the place of adobe, which might be fine for fault-free Arizona and New Mexico, but clearly not the material of choice here.

On the other hand, the frame houses in Japan have never done well, probably because the quakes are different, the earthquakes bigger, the populations larger. But the effort to earthquake-proof buildings in Japan is focused on tall structures in business districts. Japan's real success has been in disaster-proofing its citizens, with drills and signs to direct them away from danger when possible. We can probably thank these measures for keeping the death toll down, even though it will probably keep climbing for a while.

I can't help but think that we'll never get it right if we don't stop pretending that our huge footprint on the planet doesn't make disasters worse. If we didn't rely so heavily on oil refineries, nuclear plants, and giant skyscrapers, and if we were spread about more wisely, might we not prevent much of the unnecessary suffering that attends our choices to live where danger is part of the landscape? If we didn't have huge energy grids susceptable to shutdowns due to weather or attack, wouldn't our energy needs be met more efficiently, without the potential for massive impact? If we weren't so very in love with using internal combustion engines to move us around unnecessarily long distances at ridiculous speeds, couldn't we vastly reduce the amount of dirty crap we spew into the air that, in turn, seems to be intensifying natural disasters?

Thinking smaller seems to make much more sense today than ever: more local food and energy sources, fewer commuter miles, more responsive local economies. I don't think for a minute that we'll ever decide to address any of these issues in any meaningful way, but when the latest disaster news takes over the wires, I can't help but long for a more thoughtful populace, and wiser political leadership.

Image credits: An old postcard view of the Imperial Hotel opens the post; it and the photo of the earthquake aftermath are from Wikimedia Commons. The map of what's now being called the Sendai Earthquake also comes from Wikimedia Commons. The shots of damage from the Lone Pine earthquake come from Susan Hough's report report on the event, "Owens Valley: Then and Now" on the USGS Pasadena pages.

The Fault, Dear Brutus . . .

I regularly scan the New York Times online edition's science section because there's seldom any science news that doesn't stir my imagination in some way. I check the food section for similar reasons. But this morning I ran across a story that perked me right up, about a new California earthquake map that outlines faults in pretty colors.

Of particular interest to me and mine is the fact that the Owens River valley is a veritable rainbow of fault activity, a great deal of which has occurred within the last 200 years. My home town, Lone Pine, lies at the confluence of more than a dozen faults that have generated displacement over the last 700,000 years, and more than half of which have been active within historic times.

The best known event occurred in 1872, about thirty years before any of my family moved into the valley. It was notorious for teaching inhabitants a little something about how to build in seismically active territory: wood-frame buildings survived, but adobe crumbled. According to W. A. Chalfant's account in the Bible of valley history, The Story of Inyo, adobe was the architectural material of choice, since appropriate wood was expensive and scarce (260). Even the fired-brick courthouse in Independence fell, and was replaced by a wooden structure which burned down in 1886.

The current edifice was completed in 1921: a lovely Neoclassical revival building with an Ionic temple-porch at the entrance. It sits right across US 395 from the Winnedumah Hotel (also built in the '20s), where we usually stay when visiting the area. The courthouse makes a fine sight for viewing with one's morning coffee.

The 1872 temblor altered the landscape significantly, but its most visible effect is Diaz Lake--the town's major recreation facility--and a scarp line that's visible (on and off) from the grave-site of the twenty six victims all the way up to Big Pine. On the last trip I made to the Auld Sod with my father, he showed me the spot where the scarp ran across the family's old property, and where the land dropped about ten feet overnight during a later earthquake. It's roughly outlined by the treeline on the photo that opens this post, which was taken from the back of the Robinson property in Big Pine, where our family reunions are held.

Were it not for earthquakes, of course, the valley itself would not exist. As part of the Basin and Range Province (eloquently described by John McPhee in his book, Basin and Range, which my husband and I have read aloud to each other on trips west), the Owens valley is one of the westernmost examples of where mountains have emerged and valleys dropped along the edge of the American plate. The mechanisms are complex and brutal, but they're responsible for producing the gold and silver and other ores that fueled the population of the west.

The more recent history of the Owens valley includes the effects of Pleistocene glaciation and the development of a drainage system that more or less ends with Owens Lake. This accounts for the concentration of heavy metal particles in the lake bed that, when it dried up, blew out of the valley and threatened the lungs of Angelenos in the south. During my entire lifetime a struggle to get water back in the lake has been waged, and only recently have wetlands been re-established, thanks to the Lower Owens River Project. The resulting increase in bird populations and variety is astounding, and when fellow blogger Martha posted pictures of pelicans flying above Lone Pine in her Skywatch Friday entry last week I was profoundly reassured by what these birds represent. (A tourist captured a similar flock in March of 2008 at Diaz Lake and posted the video on YouTube; try to ignore the commentary.)

Nothing in the valley is permanent, of course. The very convergence of faults that appears on the new map assures us that flux is the norm rather than the exception. I rather enjoy postulating a future for the valley (it's the site at which most of my fiction takes place), using all the bits and pieces from geological history that come my way. Thus, I have a feeling that the map will inspire a story or two--perhaps this afternoon when I retire to the back yard after a slog on the computer, in a place where most of the local seismic activity comes from energy companies' drilling for gas in the Barnett Shale: an indication that human beings really aren't very good at learning lessons about geological processes.

Notes: The photo of the Sierras from Big Pine (with a the Palisade Glacier peeking through) was taken during a trip to the annual Labor Day family reunion in 2002. I shot the courthouse from the Winnedumah Hotel, where my kids and I stayed while we were in the valley during the same trip. The glacier, alas, was nearly gone the last time I visited, in 2004. The reference to The Story of Inyo is to the first edition (1922), inscribed to my father by my grandmother, and punctuated with his notes. A .pdf file of the same edition is available at the link, above.