In the 1980s, scientists initiated a study to uncover the mystery behind an orphan tsunami that struck Japan in the year 1700. The giant tsunami, which remained a mystery for three hundred years, hit the country without warning. The Japanese dubbed it an orphan tsunami because it was not preceded by an earthquake.
The catastrophic event was recorded by samurai and villagers. Fields turned into an ocean. Houses washed into the sea. These were among the accounts. Hundreds of years after, scientists finally found the orphan's parent: the Cascadia subduction zone.
Known as the Cascadia fault, it stretches from northern Vancouver Island to northern California. The recent 6.8-magnitude earthquake on Sunday in Eureka, California, was the result of clashing tectonic plates in the Cascadia subduction zone.
Recent studies are now debunking previous theories that the Cascadia fault is not capable of producing strong earthquakes. The Cascadia subduction zone is a long sloping fault that separates three plates. It is an intersection of the "Juan de Fuca," "Gorda," and "North American" plates.
According to the California Geological Survey, the fault has produced six quakes of magnitude 7.0 or more in the last 100 years. The two recent powerful quakes are 6.8-magnitude quake on Sunday and the 7.2-magnitude shaker in 2005.
Scientists said that the Cascadia fault is powerful not just because of its length. It is strong because the two tectonic plates - Juan de Fuca and Gorda - are being forced into the enormous North American plate. Because the North American plate is larger and stronger, it pushes back the two plates over time, snapping like a rubber band every 100 years.
"It could be today. It could be 100 years from now," said U.S. Geological Survey seismologist David Oppenheimer.
Researchers from the National Oceanic and Atmospheric Administration (NOAA) are now using state-of-the-art tsunami sensors off the Oregon coast to provide earlier warnings. The sensors could reportedly track the exact size of a tsunami in as little as five minutes.
"Some people had a false sense of security. You want to have this information as accurate as possible," NOAA told the Los Angeles Times.
Officials are also planning to build tsunami safe havens that will act as temporary evacuation centers. Each haven can accommodate 800 people, officials said.