The High Cost of Failure
"It's better to predict dramatic things that don't happen than boring things that do." - Nathan Myhrvold
Nathan Myhrvold is known for his culinary skill rather than his expertise in seismology. Still, the Italian National Commission for the Forecast and Prevention of Major Risks could have benefitted by adopting his whimsical insight as their institutional motto. It may have prevented a lot of legal trouble for six of the organization's scientists who were convicted of manslaughter for failing to predict a deadly earthquake in L'Aquila, Italy in 2009.
The implications of the convictions are far-reaching. The rulings almost guarantee that Italians, if not the rest of us, will get neither predictions of the dramatic nor the mundane from scientists made leery of civil or criminal penalties for getting either sort of prediction wrong.
In fairness, the issues surrounding the trial are complex, and involve failed communication more than just failed prediction. Nonetheless, the convictions continue to produce aftershocks among scientists and bureaucrats, and have sparked many debates about the role of science and government in informing the public of the risks posed by various natural disasters.
We'll never know whether bold predictions of dramatic things would have saved lives in L'Aquila. But we can safely say that public misperceptions about the methods and limitations of science, and scientist's failure to communicate their insights in lay terms can put the public and science on a collision course to that's bad for both of them.
There are lessons for both scientists and non-scientists in the L'Aquila decision. One of them is that poor understanding of basic science can be bad for your health.
The Difficulties of Predicting Earthquakes
Most of us know that science and technology are advancing rapidly because we see the advances in our entertainment and computer equipment. Anyone over 30 knows that the electronic technology of today is remarkably advanced compared the technology available 20 years ago. It's easy to assume that the advances we see in electronics are occurring in all branches of science. This is sadly not the case, and while geophysical methods have advanced considerably, there are still some significant barriers to the accurate prediction of earthquakes.
For perspective, compare weather prediction with earthquake prediction. Even without instrumentation, we can predict weather by observing changes in the medium in which it occurs - clouds, wind speed and direction, and air temperature, as examples. To predict an earthquake, though, we can only observe a small portion of the medium that produces them, and since that medium is a solid, any changes are difficult to detect. Even instrumentation has limited usefulness, because we can't put it where it would be most helpful. And unlike weather phenomena, where there are obvious measurable and dependable precursors, earthquake precursors are notoriously unreliable.
Currently, the science of earthquake prediction relies on observing quakes as they occur, mapping their epicenters and magnitudes, identifying evidence of past quake activity, and then analyzing the data to determine the average time between significant quakes and areas where they're likely to occur or recur.
Because the science relies on the past to predict the future, there are inherent limitations. That's why we often hear half-hearted warnings, like "California is overdue for a destructive quake". It's an insight that any California resident with little knowledge of seismology could have come up with on their own, but it's the best seismologists can do at the moment.
Despite the uncertainties, it's worth pointing out that earthquake precursors do exist, and that some predictive methods based on them have been used successfully. In the case of the 1975 earthquake in Haicheng, China, the city was evacuated several hours before the quake struck, saving many lives and making it the only case in which predictive methods were used to identify a major quake before it struck. The precursors included animal behavior, water level changes, radon gas emissions, and foreshocks. A subsequent quake in the region occurred with no precursors, though, and took thousands of lives.
More than understanding the limitations of seismology, it's critical to know the risks associated with them, and that more than any other factor is what the residents of L'Aquila failed to grasp. They knew that their town was in an area prone to destructive quakes, they knew that many of their buildings were old and at risk of collapse in an earthquake, and they had experienced many small earthquakes that could have been characterized as foreshocks. Yet they failed to take steps to mitigate their risk, and blamed that failure on science and government.
Earthquake Risks and Hazards
On average, there are more than 500,000 detectable earthquakes around the globe each year. About 100,000 of them can be felt, and 100 of them cause damage. Flooding and storms have killed more people, but among natural disasters, earthquakes take heavy tolls in human lives, so it's wise to understand the risks they pose and take steps to mitigate them. This is particularly true if you live in a seismically active area, like California, Japan, or L'Aquila, Italy.
Since there are only 100 or so earthquakes each year that cause damage, and the bulk of these occur on the west coasts of North and South America, the South Pacific, Italy, mainland China, and Japan, if you don't live in one of these areas, you are at substantially lower risk of experiencing a catastrophic earthquake. Earthquakes can occur on any landmass, so nowhere has a zero risk.
And because we all have some risk of earthquake damage, injury, or death, it's smart to mitigate them. Specific mitigation strategies are beyond the scope of this article, but be aware that most earthquake-related injury and death is caused by objects falling or collapsing on people, including houses, other buildings, and building components. Securing shelving, appliances, and other heavy objects that might have high centers of gravity like entertainment centers is a good initial strategy.
A very bad strategy, as illustrated in L'Aquila, is to wait for a scientist or bureaucrat to tell you what to do or where to go. In the event of an actual emergency, most of them will be heading to the nearest intact attorney's office.