Sep
11

Can Earthquakes be Predicted?

Can Earthquakes be Predicted?

September 11
By

If there’s one type of disaster that strikes without warning, it’s the infamous earthquake. Tornados at least give people some form of warning because storms take time to develop. The same is true of hurricanes. As we explored in a previous post, hurricanes develop slowly offshore and gain power as they approach the coast. But with earthquakes, there’s no real warning. We can glean a fair idea of where earthquakes will occur since they tend to happen near fault lines and where tectonic plates are in contact, but can we predict exactly when? If we could figure out when earthquakes will occur, we could give ourselves the time we need to prepare for the disaster, and therefore be much more likely to recover afterward. Can we actually predict when earthquakes will happen?

According to a recent BBC article, at this point we can’t really predict when earthquakes will occur, but we can calculate the odds that big earthquakes will strike within a broad geographic area over the next few years or decades—a practice called forecasting. We can gather a general idea, but it’s nothing concrete, and there’s not much we can do until the earthquake happens. Once it does, we can use early warning systems to let people know a quake is happening the minute the first rumbling begins, which grants people farther away from the epicenter a little bit of time to prepare. Early warning is useful, but it’s not as good as having reliable predictions.

The BBC also mentions that due to an awful lot of phony earthquake predictions in the 1970s, the idea of predicting earthquakes has a bad reputation—there’ve been a number of false alarms. Some scientists don’t even think prediction is possible (see Robert Geller’s “Earthquakes Cannot Be Predicted”), arguing that because of the immense array of factors, there’s simply no way to measure and analyze all of them, which means there might not ever be a way to predict them definitively.

Prediction might seem impossible, but that’s not to say that scientists haven’t tried their best. In the 1980s, a group of researchers covered the area near the San Andreas fault (which is known to cause regular earthquakes) with hundreds of seismometers, hoping to receive signals of an impending earthquake they had forecasted beforehand. The earthquake finally happened in 2004, but despite the fact that they were placed in the earth as deep as possible, the instruments read nothing leading up to the actual event.

When thinking about the study of faults, it’s important to understand that fault lines are very deep. For example, the BBC reports that the Hayward fault, which is parallel to the San Andreas fault, is over six miles deep. Although scientists can place instruments deep in the ground, they’re still separated from the area they need to study by about 5 miles of rock, which means they can’t get the observations they need without drilling extremely deep—deeper, in fact, than anyone has ever drilled in history.

Basically, predicting earthquakes isn’t feasible for us right now because we can’t gather and analyze all the data necessary to determine with any accuracy when a quake will occur. Predictions up to this point have even been known to create panic and unnecessary evacuations, not to mention the fact that they can offer a false sense of security to those who acknowledge them. Science is a long way from being able to predict earthquakes reliably, if they’re ever able to at all.

Although earthquakes are difficult, if not impossible, to predict, people will often turn to anomalies like odd animal behaviors, radon gas seepage from rocks, patterns in earlier earthquakes, or even electromagnetic signals from pressurized rocks. But any correlations found between these and actual earthquake events are illusory. Some who have attempted to predict earthquakes using these methods have thrown several false alarms, although one did supposedly predict real activity.

In any case, earthquakes are going to happen, and it takes time to prepare. The best way to deal with earthquakes is to determine what the hazards associated with them will be. This applies to everything from erecting earthquake-resistant buildings to ensuring things like highways and other infrastructure items will survive to having food and emergency storage. If you’re in an area with a fault line (I know I am), you’re probably at risk and should therefore take necessary steps to prepare.

Want more about earthquakes? Read this article about a café in Spain that simulates earthquakes while you eat.

Photo Credit: Seattle Municipal Archives via Compfight cc