Why are earthquakes so hard to predict?

The causes of major earthquakes, such as the magnitude 7.8 quake that struck Turkey and Syria on Monday, are well known. That doesn’t make them any easier to predict.

Despite advances in both science and technology, it remains virtually impossible to know exactly when and where earthquakes will occur.

“Earthquake forecasting has always been something of a holy grail,” said Wendy Bohon, an earthquake geologist who works as a communications strategist at NASA’s Goddard Space Flight Center in Maryland. “If we could tell people exactly when an earthquake is going to happen, we could take measures to mitigate it. But the Earth is a very complicated system.”

Part of the challenge is that the nature of earthquakes makes unpredictable events. When one happens, it happens fast.

“An earthquake is not like a slow-moving train that eventually speeds up. It’s a sudden, accelerated event,” says Ben van der Pluijm, professor of geology at the University of Michigan.

Earthquakes also tend to strike with little to no warning. While scientists have examined possible precursor events — everything from shifts in subsurface sounds to potential increases in a region’s seismic activity to changes in animal behavior — they haven’t been able to pinpoint consistent signs that tremors are imminent so far.

The lack of a clear pattern makes it difficult to make reliable forecasts comparable to weather reports.

In addition, the processes underlying earthquakes – the crushing and colliding of tectonic plates and the energy that builds up as a result – tend to play out over a long period of time. For example, scientists can estimate that an earthquake is likely to strike an area sometime in the next 200 years, which can be specific on geologic timescales. On human time scales? Not so much.

“We have an incredibly good idea of ​​where to expect earthquakes, and even the magnitude to expect for major earthquakes in these areas, but that doesn’t help us narrow that down to a human time scale,” van der Pluijm said.

The US Geological Survey is even more blunt on the subject. “Neither the USGS nor other scientists have ever predicted a major earthquake. We don’t know how, nor do we expect to know how at any point in the near future,” the agency said on its website.

Still, there are ways to prepare. The USGS has developed an early warning system called ShakeAlert that detects when a significant earthquake has occurred in California, Oregon and Washington and then broadcasts radio, television and mobile alerts saying strong shaking is imminent. In most cases, the alerts only provide a few seconds of warning, but that time can be extremely valuable, says van der Pluijm.

“Twenty seconds sounds really short, but it’s enough time for you to find a spot under a desk to take cover,” he said. “It’s not a prediction, but ShakeAlert is a huge step forward because it can minimize the inevitable impact.”

One of the most important ways to prepare for an earthquake is to be aware of the risks, Bohon said. For policymakers, this means protecting critical infrastructure in earthquake-prone areas.

“What we need to do is make sure we understand what can happen and build to resist that,” she said. “We need to make sure people know what to do. We need to ensure that our cities can be resilient to those hazards so that we not only survive the earthquake, but also its aftermath.”

This article was originally published on NBCNews.com

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