Big Quakes Can Trigger Other Shakes Thousands of Miles Away

An earthquake felt round the world. Research shows that large earthquakes may trigger smaller earthquakes thousands of miles away.


On April 11, 2012, an 8.6 magnitude earthquake in the Indian Ocean shook the Sumatran coast. Only a day later—3,900 miles (6,230 km) away—seismologists detected a set of smaller temblors rattling the eastern coast of Japan.