The largest was a 9.5 magnitude event that struck Chile in 1960, causing 1,655 fatalities, leaving 2 million homeless, and triggering a tsunami that killed people in Hawaii, Japan and the Philippines.
Scores of countries around the Pacific Ocean are bracing for a tsunami unleashed by the latest quake, and which is now speeding across the ocean at 550 miles per hour, or the speed of a jet plane.
“A tsunami has been generated that could cause damage along coastlines of all islands in the state of Hawaii,” noted the U.S. government’s tsunami warning center in Hawaii.
Tsunami-causing quakes usually occur where shards of the earth’s crust—tectonic plates—meet. Magma rises from deep inside the earth, causing the plates to move. They slip-slide past each other, sometimes get stuck, then jerk forward again, producing a quake.
According to the USGS, the Chile earthquake occurred at the boundary between the Nazca and South American tectonic plates. The two plates are converging at a rate of 80 mm per year, with the Nazca plate moving down and landward below the South American plate.
Tsunami—great. At least Hawaii and Japan are prepared.