Researchers found multiple faults with evidence of more than 10 meters of slip during past large earthquakes in the region hit by the 2011 Tohoku-Oki earthquake and tsunami.
In the aftermath of the devastating Tohoku-Oki earthquake that struck off the coast of Japan in March 2011, seismologists were stunned by the unprecedented 50 meters of shallow displacement along the fault, which ruptured all the way to the surface of the seafloor. This extreme slip at shallow depths exacerbated the massive tsunami that, together with the magnitude 9.1 earthquake, caused extensive damage and loss of life in Japan.
In a new study, published January 27 in Nature Communications, researchers used a novel technique to study the faults in the Japan Trench, the subduction zone where the Tohoku-Oki earthquake struck. Their findings reveal a long history of large earthquakes in this fault zone, where they found multiple faults with evidence of more than 10 meters of slip during large earthquakes.
“We found evidence of many large earthquakes that have ruptured to the seafloor and could have generated tsunamis like the one that struck in 2011,” said coauthor Pratigya Polissar, associate professor of ocean sciences at UC Santa Cruz.
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