Showing posts with label earthquake prediction. Show all posts
Showing posts with label earthquake prediction. Show all posts

Monday, January 18, 2016

Earthquake Prediction Goes Commercial — Sort Of


Everybody's now used to seeing weather maps with "past" and "future" buttons on them, allowing you to see what the weather is likely to be a day or two ahead of time.  Did you know there is at least one company that is now publishing a similar map of the world that depicts regions that may shortly experience earthquakes?  QuakeFinder, which calls itself a "humanitarian R&D project" of a parent firm named Stellar Solutions, has a Public Data Center page where they put little red dots in regions that have experienced a change in electromagnetic activity, which (according to QuakeFinder) has been correlated with future earthquakes.  I don't know how much traffic their site attracts, and so far I haven't seen any red dots show up, but I just found out about the site today. 

QuakeFinder bases their predictions on three types of data:  (1) ultra-low-frequency (ULF) magnetic fields, (2) concentration of ions in the air, and (3) emission of infrared radiation as monitored by satellites.  A number of studies over the last few decades have turned up situations in which disturbances in all three quantities have preceded medium to large earthquakes in many locations.  Of course, it's a long stretch between noticing some correlations and using data to make specific predictions about earthquakes.  But at least two organizations—QuakeFinder and another outfit called GeoCosmo—seem to think that there's enough data to start estimating the timing, location, and size of future earthquakes.

I will leave the question of whether QuakeFinder's predictions are accurate aside for the moment, and turn to what might be an even more vexing issue:  once you have a way of predicting earthquakes with some degree of precision, what should you do with it?

A lot depends on the level of false positives (times you say there will be a quake and nothing, or almost nothing, happens) and false negatives (times you miss making a prediction and an earthquake catches you by surprise).  Let's say for the sake of argument that the system does as well at predicting earthquakes as today's weather forecasters do at predicting tornado activity.  I don't have exact statistics on hand at the moment, but my sense is that the great majority of the time when a region is in a tornado watch, some violent weather usually occurs—either a tornado or high winds that can cause as much damage as a small tornado.  And the weather prophets very rarely get caught napping nowadays by failing to predict violent weather, although there are times when a storm becomes a lot worse than forecasts predicted.

At one extreme, it would be the height of moral irresponsibility to know that a major earthquake is going to hit a populated area (where "know" means, say, an 80% chance), and not do anything to let the affected people take precautions.  So the development of a truly reliable earthquake prediction system carries with it the moral obligation to share the information in some form with the general public.

On the other hand, what sorts of precautions should be taken if earthquake prediction becomes a reality?  I can imagine different degrees of preparedness for different groups.  First responders and emergency services would take such predictions most seriously by increasing reserve staffing and supplies and heightening their readiness for a crisis.  People in structures that are known to be especially vulnerable to earthquake damage might consider just staying away for a few days.  Depending on how far in advance a quake could be predicted, this could be a problem. 

It's not clear yet whether earthquake prediction will share with tornado prediction the characteristic that shorter time spans mean more accurate predictions.  If a weather radar shows a tornado two miles west of you heading east at thirty miles an hour, it's pretty easy to say you'll be in big trouble in about four minutes.  It's possible that the best earthquake predictions may never provide time windows narrower than many hours or even days.  Making people stay home or in earthquake-resistant shelters for several days is simply not going to fly, so a lot will depend on how chronologically precise the predictions can be made. 

Another important question is, who's going to pay?  When scientific prediction of weather first became possible in the late 1800s, the economic and military advantages of doing so were so obvious that most national governments established weather bureaus or the equivalent, and for many years government weather prediction was the only show in town.  The observation end of weather forecasting—all those weather stations, weather satellites, and people keeping records for decades—is still expensive, and borne largely by government agencies, but a large number of private weather-forecasting firms now take government data and use it for both public predictions through the media and specialized predictions through commercial transactions.

So far, the model used by QuakeFinder is a non-profit one, although the line dividing a non-profit organization from a commercial operation is not always that easy to draw.  QuakeFinder does apparently have "subscribers" who presumably get customized data.  Weather bureaus and weather forecasting prospered because their forecasts were accurate enough to be valuable, and we can expect earthquake forecasting to be held to a similar standard.  On its website, QuakeFinder claims to have predicted a couple of Peruvian earthquakes, which claim is confirmed indirectly by contemporary news reports citing the involvement of a "California company" (presumably QuakeFinder) in a prediction by a Peruvian scientist of two medium-size earthquakes in Peru in April of 2013. 

But just as two swallows don't make a summer, two predictions don't make a successful prediction system.  Large segments of the scientific community remain unconvinced that earthquake prediction is anything more than a slightly informed guess.  According to some sources (including journalist Alberto Enriquez), one of the biggest wet blankets on earthquake prediction is the United States Geological Survey (USGS).  Apparently back in the 1980s, this agency received extra funding to develop earthquake predictions, and they got burned when their forecast of a major earthquake (again in Peru) failed to materialize in 1981.  Ever since, according to Enriquez, they have been critical of earthquake prediction and have made it hard for researchers to publish in this area or to receive funding.

But other agencies such as the National Aeronautics and Space Administration (NASA) are supporting the work of researchers such as Friedemann Freund, who has been mentioned previously in this space as the developer of a theory (confirmed by experiments) that stressed rocks can produce large electric and magnetic fields when mobile charge carriers he calls "p-holes" arise in them.  Freund is one of the founders of GeoCosmo, which focuses on earthquake prediction studies.

The nice thing about private enterprise is that it's self-limiting.  If QuakeFinder or GeoCosmo get it right often enough, people will start paying attention.  Let's hope they can figure out how to do it and get taken seriously enough to save some lives before the next big quake hits.

Sources:  I thank Alberto Enriquez for drawing my attention to recent developments in this field through his website http://seismoem.com/blog/earthquake-forecasting-is-here-today.  QuakeFinder's website is at https://www.quakefinder.com/.  GeoCosmo's website is geocosmo.orgA news report on June 25, 2013 providing independent confirmation of the Peruvian earthquake prediction attempt is at http://www.peruthisweek.com/news-peruvian-geologists-may-be-able-to-predict-earthquakes-100220.  I also referred to an article by Julia Rosen carried on the American Association for Advancement of Science Science website, entitled "Can electric signals in Earth's atmosphere predict earthquakes?" at http://www.sciencemag.org/news/2015/12/can-electric-signals-earth-s-atmosphere-predict-earthquakes.  Friedemann Freund's research in "seismoelectromagnetics" (the electric and magnetic fields produced by stressed rocks) was summarized in this space in "Global Warming or Global Shaking?  A Tale of Two Theories" on Feb. 20, 2007.

Monday, October 29, 2012

Prison Terms for Careless Words: The L’Aquila Seismology Verdict

 
Suppose you are a citizen of the medieval Italian town of L’Aquila.  Your city has survived several earthquakes in its history, including ones that led to considerable loss of life in 1461 and 1703.  In late March of 2009, you notice that there have been small tremors lately that perhaps rattle a dish or two, but this is nothing particularly unusual in highly seismic Italy.  However, a lab technician in a town thirty miles away garners some publicity when he announces that a method he’s come up with to predict earthquakes is telling him there’s going to be a big one soon.  You wonder whether it will be worth the trouble to sleep outside, which is something you have done on occasion when the temblors get severe.

Then you tune in to a news report of an announcement by a seven-member expert commission made up of seismologists, engineers, and a government official.  The panel’s conclusion is that the tremors over the past four months pose “no danger.”  In fact, one of the panelists says that “in fact it is a favorable situation, that is to say a continuous discharge of energy.”  This makes you feel better, and you decide to continue sleeping indoors.

Six days later, at 3:30 in the morning on April 6, a 5.8-magnitude earthquake hits L’Aquila.  You survive, but many people are killed, about 300 in all, and hundreds of buildings of both medieval and modern construction either collapse or are severely damaged.  Now the question:  what should be done about that panel of experts?

The Italian legal system has answered that question.  On Oct. 22 of this year, all seven members of the panel were convicted of manslaughter and sentenced to six years in prison.  This verdict has made headlines around the world for a number of reasons.

Italian prosecutors insist that the scientists and engineers are not being charged with failing to predict the earthquake.  Everyone (or nearly everyone) acknowledges that earthquake prediction is still an inexact science compared to weather forecasting, for instance.  But except for relatively rare fatal storms such as hurricanes and tornadoes, one’s life does not depend on the accuracy of a weather forecast.  The government prosecution contended that the panel’s reassurances that the temblors did not mean an earthquake was imminent, prevented L’Aquila residents from sleeping outside and thus led to a larger number of deaths than if they had kept quiet.

For the convicted scientists and engineers, things may not be quite as bad as they seem.  On average, in Italy about four out of five convictions involving prison terms are never put into effect, due to reversals on appeal or other reasons.  Nevertheless, these convictions are a sobering warning to experts who make public pronouncements about the possibility of earthquakes.

An article on the conviction in The Economist carried the subhead “Damned if you do, damned if you don’t.”  Earthquake experts asked to predict quakes face a classic dilemma.  If they fail to predict an earthquake that occurs, they can be charged with negligently giving bad advice that led to fatalities, at least in Italy.  But if they go to the other extreme and sound the alarm any time it looks like a quake might happen, they are liable to cause panic, or else to be wrong so often that people will ignore them even when they turn out to be right.  The independent prediction by the lab technician that his radon-based method was saying an earthquake was coming caused panic in a nearby town, and it is possible that the L’Aquila commission felt obliged to calm troubled waters.  It was their bad fortune to take that position less than a week before the fatal quake that did happen.

While the U. S. has perhaps a more robust tradition of free speech, including the freedom to give opinions about public dangers without worrying about manslaughter charges, the unhappy experience of the Italian earthquake scientists and engineers is a cautionary tale for any expert who makes public pronouncements on matters relating to safety.  Despite appearances, people do listen to experts and sometimes even take their advice.  I am not aware of any doctors from the 1950s who were quoted in TV ads as saying smoking was harmless, and then were sued or charged with manslaughter after it was shown that cigarettes cause cancer.  But that may be because a powerful industry fought the idea for decades.  No well-funded interest group had a vested interest in showing that the scientists had science on their side when they dismissed the possibility of an imminent quake.  Other members of the Italian National Institute of Geophysics and Vulcanology (NIGV) did some Monday-morning quarterbacking after the quake and calculated that the chances of a big earthquake happening in the 10-km region around the city rose from a normal background of 1 in 200,000 to a much greater, but still small, chance of 1 in 1000 a few hours before it actually occurred.  But one chance in a thousand is still a pretty long shot, and even if the panel had announced this relatively great increase in the likelihood of an earthquake, they might still have found themselves in the dock.

Part of the problem is that most average citizens do not want to deal in probabilities.  They want to know, “Are we going to have an earthquake or aren’t we, and if so, when?”  Unfortunately, the science we have so far can only deal in probabilities, and if experts are asked to give more than raw statistics about a possible future event, they tend to send a message that is either reassuring or alarming, depending on the tone of the situation and any number of other extraneous factors.

Let us hope that the Italian convictions don’t persuade seismologists to eschew forecasting as too personally risky to engage in, because a robust and reliable science of earthquake forecasting would be a valuable thing that could save lives.  But if earthquake scientists feel that they are putting their personal lives and liberty at stake every time they issue an opinion, the science and engineering pertaining to earthquakes could itself suffer long-term damage as an unexpected casualty of the L’Aquila disaster.

Sources:  Besides the two articles in The Economist on the seismologists’ trial (one on Sept. 17, 2011 after the indictment at http://www.economist.com/node/21529006
and the second on Oct. 27, 2012 at http://www.economist.com/news/science-and-technology/21565135-italy-sloppy-seismology-can-lead-prison-reason-tremble), I used an article on the Italian legal system at http://www.justlanded.com/english/Italy/Articles/Visas-Permits/Legal-System, and I referred to the Wikipedia articles “Italian Code of Criminal Procedure” and “2009 L’Aquila earthquake.”