quakes can drop land

We often think of sea level as the height of water relative to the land. But geologists know that the land is also in motion, somewhat complicating measurements of rising sea level. (Alaska, which is tectonically rising, records less apparent sea level rise than elsewhere, for example.) In cases where land is subsiding, sea level rise may actually seem augmented. And no part of the Earth underwent a quicker subsidence than areas of coastal Japan during the great quake of 11 March 2011.

As a recent story confirms,

The March 11 earthquake that hit eastern Japan was so powerful it pulled the entire country out and down into the sea. The mostly devastated coastal communities now face regular flooding, because of their lower elevation and damage to sea walls from the massive tsunamis triggered by the quake.

One of my professors of geology remembers camping on a beach the night of the 1992 Mendocino earthquake, and finding in the morning that the coastline had been visibly uplifted, exposing mussell-covered rocks now well-above the high tide line, dooming their sessile molluscan tenants.

While we human like to imagine the solid land as solidly fixed in one place, the reality is far more complex, though our short life spans rarely allow us to the opportunity to observe changes first hand. This the nature of deep time; we can see the long term effects of geologic changes but usually only indirectly observe them occurring.

Japan is an exception:

Some areas in Ishinomaki moved southeast 17 feet (5.3 meters) and sank 4 feet (1.2 meters) lower.

"We thought this slippage would happen gradually, bit by bit. We didn't expect it to happen all at once," says Testuro Imakiire, a researcher at Japan's Geospatial Information Authority, the government body in charge of mapping and survey.

The now permanent situation in Japan should give those of us who live in California a moment of pause to reflect on how quickly the land around may one day change.

Serpentinite Expelled?

Oh noes! Teh iz coming foar mah rx!

"California may drop rock, and geologists feel the pain." As amazing as it sounds, the official state rock of California, serpentinite, is in jeopardy of losing its status, due to a bill by LA Democrat Gloria Romero. Romero rightly points out that California's state rock is chock-full of chrysotile asbestos, and for this reason she finds it inappropriate for this lovely, lime-green rock to be so honored by the Golden State.

The New York Times article on this--which repeats the common mistake of referring to the rock (serpentinite) by its group of mineral (serpentine)--correctly quotes a USGS geologist as saying, "There is no way anyone is going to get bothered by casual exposure to that kind of rock."

People have a hard time getting their minds around this, but we Californians are frequently exposed to asbestos fibers without demonstrably increased rates of cancer. This is especially true in the serpentinite-rich Bay Area (the alleged elevated breast cancer rates in Marin are not connected with this fact). But if we're breathing asbestos in normal air, why aren't Californians who don't smoke dropping dead of lung cancer?

For one thing, chrysotile asbestos is not the most carcinogenic asbestiform mineral--that honor goes to "blue asbestos," crocidolite, and "brown asbestos," amosite.

But unlike these two forms, chrysotile's fibers are slightly curved, meaning that they cannot penetrate quite so deeply into the small passages of the lungs. When lungs are exposed to mineral particles, they react as if these particles were viruses or bacteria; a robust immune system attacks these particles with a toxic brew of chemicals. In a way, our immune system is too good at doing this, because in the process of trying to "kill" the mineral, neighboring cells are damaged in ways that, given enough time, can turn them cancerous. The longer mineral particles remain, the longer the immune reaction occurs; the problem with asbestos fibers is that they lodge so deeply, it is very difficult for them to be dislodged.

I don't want to minimize the health hazards of asbestos, or imply that it does not cause cancer. But it's important not to exaggerate the ill effects of hazardous substances, and to understand what actually does cause harm. It should be noted that one of the more inert substances in nature--silicon dioxide, which in a mineral form is quartz--can also cause a particularly vicious lung disease called silicosis. The bottom line is that you don't want to inhale any mineral particles if you can help it; asbestiform minerals are particularly bad to inhale, and within this mineral group, amosite and crocidolite are the worst. Since most industrial asbestos was chrysotile, this means that the efforts to remove all asbestos from places such as schools has been largely an unnecessary effort, meant to placate fears more than actually protect people. Sure, less exposure is better--although by removing the material, that increases its dispersion and people's exposure.

On a side note, the first half of the South Tower of the World Trade Center had its beams wrapped in asbestos fibers. (This fact alone shows the lie in the EPA's post 9/11 statement that the air quality was non-hazardous.) This fireproofing could be literally sewn around beams in such a way that a sudden jolt--such as an earthquake or a plane

impact--would not knock it off. While the WTC was being built, however, the use of asbestos was discontinued. The North Tower and the upper portions of the South Tower were sprayed instead with a fireproofing foam. There wasn't much science to the amount added; workers recalled that they were instructed to just eye-ball it. No one expected that something would happen to the towers that would knock this insulation off the support beams, exposing them directly to fire. Had they been wrapped in asbestos sheets, this would not have happened. Can we infer therefore that asbestos insulation would have saved the WTC? No, that goes too far--but it might have bought a little more time before the collapses.

Romero's bill has good intentions, but does not take good science into account, but instead plays upon people's fears of a substance they little understand. Moreover, it overturns a tradition, and for that reason if for nothing else, it deserves not to pass.