After a 7.5-magnitude earthquake on Monday, Japanese officials issued a rare warning for a potentially even larger follow-up.

Two major earthquakes on opposite sides of the Pacific within two days have sharpened scientific and public focus on the risks of far larger seismic events—and on how little can still be predicted ...

A powerful 6.9 magnitude quake rattled northern Japan Sunday evening, followed by several aftershocks, according to the Japan Meteorological Agency (JMA). A tsunami advisory was issued, but it was ...