A 1954 earthquake that rattled Northern California was likely caused by the infamous Cascadia Subduction Zone, a new study finds.
The linking of the magnitude 6.5 quake with this particular seismic zone is important, because the Cascadia Subduction Zone, which stretches from northern California to Vancouver Island in Canada, is not known to give off many small or medium quakes. In seismology parlance, the fault is "locked," or unmoving. The last known rupture was a massive magnitude 9 earthquake in 1700 that caused landslides and an enormous tsunami that was so powerful that waves over 16 feet high (5 meters) hit Japan, according to the U.S. Geological Survey.
