Saturday, May 28, 2011

Thursday, May 26, 2011

Seismologists responsible for the deaths earthquakes cause? Really?

crossposted from Daily Kos

Yep, that headline is not hyperbolic. It's an actual case ongoing in Italy right now. It's also outrageous.

L'Aquilla is a city located in central Italy. It is the capital of the Abruzzo region. It also sits in a region that is seismically active. All of Italy is, as it sits astride the boundary between Europe (well, Eurasia) and Africa, giving the nation its famous volcanoes such as Etna and Vesuvius, and earthquakes that have long rattled and destroyed cities for as long as we humans have been building them.

L'Aquilla was no different. An earthquake hit the place in December of 1315. Another one hit in January of 1349, during the height of the Black Death. A 1703 quake utterly flattened the place, as did another one in the summer of 1786. So it's not like the hazard was unknown. Perhaps, somewhat forgotten, as we've seen in recent quakes all over the world, the quake you expect and plan for may not be the one you get (see, Tohoku, both Christchurch/Canterbury quakes, and Port-au-Prince).

When 2009 rolled around, something odd happened in the Abruzzo region. A laboratory technician detected elevated levels of radon burping up from the ground, went on television, and stated a major quake was coming for the area. Now, it's well established that sometimes, radon emissions can sometimes portend a future quake. There is some evidence of this fact, and in fact, elevated radon was detected before March's megaquake off of Northeast Japan. But more often than not, this does not lead to much of anything. Indeed, I live over a formation that farts up radon on a regular basis all over my state, and we almost never have earthquakes (which doesn't mean they haven't happened, or don't happen, or won't happen. The written historical record is too short to really know what the largest quake Pennsylvania can have, and that's a topic for another time.)

Says Chris Rowan (from the linked article above):
I’m not pointing this out because I think that proposed precursors such as radon emissions and EM signals are not worth studying: there is enough evidence to suggest that some of these signals are indeed related in some way to tectonic processes in the subsurface. However, studies like this are often reported as a definitive step towards the holy grail: reliable, timely warnings of imminent seismic activity. The abundance of false positives is a clear indication that things are nowhere near this clear cut. When your ‘precursor’ signal is only associated with an earthquake one time in ten, or even one time in four, you’ve obviously still got a lot of work to do. Perhaps one day there will be some theoretical or technical breakthrough that allows us to distinguish real precursors from the noise. But until that day, whenever you read a story that describes some phenomenon that preceded a large earthquake, and dangles the carrot of true earthquake prediction, don’t just look at the headline event. Check for false positives.

Radon emissions, among other things, were also detected prior to Loma Prieta (also known as the San Francisco Quake of 1989, although technically, its epicenter was closer to Santa Cruz).

Like Rowan, I'm not saying this is an area of potential research to be ignored, however.

Back to Italy. Essentially what happened is the technician went on tv, scared a bunch of people that a disaster was imminent within a short timeframe, and was reported to police. Italian geophysicists then stated that earthquakes can't be predicted with precision (true) and that people shouldn't worry too much, beyond having their normal disaster plans ready. Preparedness never hurt anyone, don'tcha know.

In addition, a series of smaller quakes had rattled the region, and nerves. We know now they were foreshocks, but foreshocks cannot be identified as such until after the fact.

The earth had other ideas. Within the week, in fact.

At 3:32AM (local time) on the 6th of April, 2009, an M6.3 quake ripped through the region along a normal fault trending NW-SE. Its hypocenter was only 5.9 miles beneath the surface of the Earth, thus making it a very shallow earthquake. As we've seen time and time again, most recently with Spain's M5.3 near Lorca, even a moderate earthquake like this one can be catastrophic when close to the surface, even in nations well acquainted with seismic hazard (again, see Christchurch).

The quake rattled all of Central Italy, swaying buildings in Rome and Naples. It devastated L'Aquilla, and killed 309 people.

L'Aquilla had considerable medieval building stock, but it was modern buildings that suffered the most. A hospital wing and dorm collapsed. Aftershocks caused even more collapses. Modern buildings, in a nation well acquainted with seismic activity, should not just collapse. We'll get to that. But unreinforced masonry, buildings known to be deadly in an earthquake, proliferated in L'Aquilla and after the quake the streets were full of masonry debris.

Fast forward to today.

A judge has decided that those geophysicists who met and stated there wasn't much to worry about should be charged with the deaths of those 309 people. This is where it gets queasy for me, and for anyone who respects science and how it works. From the nature article:

The seven were on a committee that had been tasked with assessing the risk associated with recent increases in seismic activity in the area. Following a committee meeting just a week before the quake, some members of the group assured the public that they were in no danger.

In the aftermath of the quake, which killed 309 people, many citizens said that these reassurances were the reason they did not take precautionary measures, such as leaving their homes. As a consequence, the public prosecutor of L'Aquila pressed manslaughter charges against all the participants in the meeting, on the grounds that they had falsely reassured the public (see Italy puts seismology in the dock). After several delays, the public prosecutor Fabio Picuti and the defendants' lawyers appeared this week before Giuseppe Gargarella, the judge for preliminary hearings, who had to decide whether to dismiss the case or proceed with a trial.

Note the area in bold. People, living in a nation that rattles from the top of the boot to the heel on a regular basis, did not take any real precautions. In addition, could they? It's fairly clear reading the damage reports that modern buildings failed as badly as the ancient ones did, if not worse.

Another take away quote:
Boschi has said in interviews that he feels "devastated" by the ruling, and that he expected the case to be dismissed. He notes that there are hundreds of seismic shocks every year in Italy: "If we were to alert the population every time we would probably be indicted for unjustified alarm," he said. He also denied ever having reassured the population or downplayed the risk. "There is no document whatsoever proving I did something like that," he says, adding that the main cause of the tragedy was the poor building standards in the area. "I hope the trial will better clarify what role the seismologists really had in this story".

At any rate the trial begins in September.

A guilty verdict, I believe, would be a chilling effect across a wide swatch of science, not just seismology. For one thing, radon emissions do not (often don't) result in large quakes afterwards. If we warned regions every time someone's radon detector went nuts, people would stop listening, in addition to the chaos such a warning would cause. And we already know what happens when people don't listen to warnings. In the Midwest, until recently, tornado sirens sounded for an entire area, instead of just targeting the area of town the tornado was actually going to hit. I suspect this may be part of the reason Joplin's death toll is so abnormally high, as every story I've read has stated that people heard the warnings for up to 20 minutes before the tornado scythed through the city. On the East and Gulf Coasts people ignore hurricane warnings, because the storms weakened or veered off at the last moment. This is especially true in areas that have not seen intense hurricanes for many decades, like New England (the last major storm was Bob in 1991, the last intense storm before that was Carol in 1954). This is a part of human psychology that can't exactly be helped, without constant education.

And it could cascade. What if the Japanese decide to sue their seismologists? A consensus over whether the fault that broke in March could produce an M9 (the last probable one occurring in the year 869) was slow to build, and the Japanese have always focused on the region southwest of Honshu. Or anywhere else, where infrequent, high risk hazards occur. We can't just charge the scientists for something that is largely not within their control, especially with earthquakes since they cannot be predicted, and only forecast under the fuzziest of conditions, with any real precision or accuracy.

If found guilty, the scientists go to jail for up to 12 years. We shall see what happens.

The Radon paper, incidentally, can be found here.