Why earthquake predictions are usually wrong

Brent Dmitruk calls himself an earthquake predictor.

In mid-October, he told his tens of thousands of social media followers that an earthquake would soon hit at the westernmost point of California, south of the small coastal city of Eureka.

Two months later, a magnitude 7.3 struck the site in northern California - putting millions under a tsunami warning and growing Mr Dmitruk's following online as they turned to him to forecast the next one.

"So to people who dismiss what I do, how can you argue it's just a coincidence. It requires serious skill to figure out where earthquakes will go," he said on New Year's Eve.

But there's one problem: earthquakes can't be predicted, scientists who study them say.

It's exactly that unpredictability that makes them so unsettling. Millions of people living on the west coast of North America fear that "the big one" could strike at any moment, altering landscapes and countless lives.

But just because you cannot predict when an earthquake will strike doesn't mean you have to be unprepared, experts said.

Each year, on the third Thursday in October, millions of Americans participate in the largest earthquake drill on earth: The Great Shake Out.

It was created by a group at the Southern California Earthquake Center, which included Ms Jones.

During the drill, people practise the guidance of Drop, Cover, and Hold On: they drop to their knees, take cover under a sturdy object like a desk, and hold on for one minute.

The drill has become so popular since its inception that it has spread up the earthquake-prone coast to other states and countries.

If outdoors, people are advised to get to an open space away from trees, buildings or power-lines. Near the ocean, people practise fleeing to higher ground after the shaking stops to prepare for the possibility of a tsunami.

"Now, while the ground is not shaking, while it's not a very stressful situation, is really the best time to practise," said Brian Terbush, the Earthquake and Volcano Program Manager for the Washington state Emergency Management Division.

Apart from the drills, residents of West Coast states use a phone alert system maintained by USGS called ShakeAlert.

The system works by detecting pressure waves emitted by an earthquake. While it can't predict when an earthquake will happen in the distant future, it does give seconds of warning that could be life-saving. It is the closest thing to an earthquake "predictor" that has been invented so far.