Major US Cities At Risk Of Catastrophic Quake, Warns Study

The Cascadia Subduction Zone (CSZ) is a major geological faultline that stretches from Northern California in the US to British Columbia, Canada's western most province. This 1,000-km-long mega fault marks the boundary between the Juan de Fuca and North American tectonic plates. It is not just a point of interest for geologists; it is a potential source of one of the most powerful earthquakes and tsunamis the world could experience. And a new study has put it into a sharper focus. The research, published in the journal Science Advances on June 7, says the regions covered by CSZ might rupture individually or they could all unleash a massive temblor at once.

However, the impact of the quake might be different in each zone.

"It requires a lot more study, but for places like Tacoma and Seattle, it could mean the difference between alarming and catastrophic," Live Science quoted the study's co-author Harold Tobin, a geophysicist at the University of Washington, as saying.

The study of Cascadia Subduction Zone is important because plates like these can witness massive earthquakes that could generate tsunamis 100 feet or more.

Such a faultline caused the Fukushima nuclear disaster. Geologists believe that big earthquakes occur at CSZ roughly every 500 years. The last one was in the year 1700.

This study seeks to give scientists better understanding of the CSZ's subterranean structures and mechanics. The last major study on it was done in the 1980s, but since then, equipment have become sophisticated and advanced.

So, for the latest study, they measured 900 kilometres of the subduction zone and the data revealed that the oceanic crust is not only subducting, or diving down, it is also breaking up. "Now that we have actual information spanning the whole region we know that the fault surface is much more complex in its geometry than the picture we had from that very old data," lead author Suzanne Carbotte told the outlet.

There are no record of the 1700 quake but drowned trees and a mystery tsunami recorded in Japan reveal that on January 26 of that year, a magnitude 8.7 to 9.2 quake shook the region. Such a strong quake could devastate cities like Seattle, Portland, and Vancouver, leading to severe infrastructure damage, loss of life, and long-term economic disruption.

The research team now believe that the new study will help them better map the hazards and predict the next Cascadia quake.