Why can’t we predict earthquakes yet?

775px-sanfranciscoearthquake1906At least 50 people died in a 5.7 magnitude earthquake that hit China this morning, and another 20,000 homes were damaged. The quake hit Yunnan, and the nearby Guizhou provinces, home to some of China’s poorest people. Of course, they didn’t see it coming.

From who will win the most Olympic medals, to Nobel Prizes, humans – and the machines they’ve designed – have gotten pretty good at predicting things. Complicated computer models can tell us where wildfires will spread, when two planets might collide and how high our oceans might rise due to melting ice caps. But we still can’t predict earthquakes. What gives? Shouldn’t we be able to figure out where the plates will give and when?

Well, you’re not the only one asking. Science wants the answer to that question too. To find out, researchers recently looked at the three deadliest earthquakes in recent history: Wenchuan, China in 2008, Leogane, Haiti in 2010 and Tohoku, Japan in 2012. They found that all three occurred in places where even the hazard maps – out best guesses for earthquake prediction – didn’t expect them to be.

“We’re playing a complicated game against nature,” the study’s first author, Seth Stein of Northwestern University, said in the press release. “It’s a very high stakes game. We don’t really understand all the rules very well.”

This is a big deal not just to save lives, but to save money too. Countries each spend a certain amount of money to prevent damage from natural disasters. Knowing where to spend that money could save both lives and the economy.

The inability to predict earthquakes often confuses us non-scientists too. “The public is accustomed to the uncertainties of weather forecasting, but foreseeing where and when earthquakes may strike is far more difficult. Too much reliance on earthquake hazard maps can have serious consequences,” Mian Liu, another researcher on the study, staid in the press release.

In Italy, six seismologists were even tried for manslaughter in court for failing to predict an earthquake. The New York Times explains why that trial has outraged scientists all over the world:

Earthquakes differ from other types of natural disasters. Meteorologists can track a hurricane with precision, but seismologists cannot predict exactly when and where an earthquake will occur. Scientists have condemned the Italian prosecution for this reason, saying the defendants are on trial for failing to do something that is impossible.

For the researchers, there were a few standout reasons that hazard maps failed. First, earthquakes are complicated. Second, historical records in most places don’t go back long enough to get a good sense for patterns – since earthquake trends tend to emerge only on long time scales. The combination of bad and incomplete data, with a complicated system, means that hazard maps are guesses at best. The study writes:

As a result, key aspects of hazard maps often depend on poorly constrained parameters, whose values are chosen based on the mapmakers’ preconceptions. When these are incorrect, maps do poorly. This situation will improve at best slowly, owing to our limited understanding of earthquake processes.

What can we do about it? Well, we can wait to gather more data. Which means waiting for more earthquakes to happen. We can also test the maps, the authors say. Which, of course, isn’t so easy either. Even they admit that, “There are likely, however, limits on how well hazard maps can ever be made because of the intrinsic variability of earthquake processes.”

Source: Smart Planet.



Etna hoops it up.

Volcanologists have witnessed dramatic rings of steam and gas being blown out of volcanic vents on the side of mighty Mount Etna in Sicily.

Etna is the tallest and most active volcano in Europe, situated where the European and African geological plates are colliding.


Dr Jug Alean and Dr Marco Fulle have been investigating Etna’s growing level of activity and in February they saw the ejection of several spectacular hoops from the Bocca Nuova region of the mountain.

“This wonderful specimen gently drifted overhead and past the Sun which was tinted orange by aerosols in the smoke,” Dr Alean told BBC News Online.

It is difficult to gauge the size of what the scientists are calling “steam rings”. They drift across the blue sky with no points of reference. However, the volcanologists estimate the hoops to be about 200m across and up to 1000m above the ground.

Stable shape

Smoke rings have been seen at volcanoes before but never in such detail. This time, there was hardly any ash on Etna and the gas billowing from vents had a high steam content. It is for this reason that Drs Alean and Fulle are using the term “steam rings”.


Looking like the hoops produced by smokers, the hoops can hang in the air for many minutes. Etna’s rings have been seen to last as long as 10 minutes.

How they are formed is a mystery that these pictures may help solve.

Dr Jurg Alean speculates: “They could be formed by rapid gas pulses emitted by narrow vents into the atmosphere. The physics seems somewhat complicated and I am trying to establish if there are sound scientific theories about them.”

Drs Alean and Fulle keep a close eye on Etna, running a private seismic monitoring station as well as maintaining a photographic record of changes on the mountain. Their website, stromboli.net, contains some of the most dramatic volcano pictures ever taken.

Source: BBC science.