What Happened in the Japanese Earthquake—and Why It Could've Been Worse

Japan's massive earthquake today may be over, but we're still feeling the effects, from nuclear reactor scares in Japan to tsunami warnings along the entire west coast of North America, from Mexico to Alaska's Aleutian Islands. Much is still unknown about this earthquake, including official destruction assessments and total death tolls, but here's what we do know: Two preliminary earthquakes with magnitudes of 7.2 and 6.3 struck off the coast of Honshu, Japan, the day before the major blow: This 8.9-magnitude quake---the largest in Japan's recorded history---struck at 2:46 pm local time on Friday, its epicenter located about 231 miles northeast of Tokyo at a depth of 15 miles. Even after this large one, over thirty aftershocks---the strongest measuring 7.1 in magnitude---continued to batter the island nation. The Immediate Effects Fires and collapsed buildings were the main cause of injuries and death early on, from conflagrations sweeping an oil refinery ...