The Grid: Charting 2010's Biggest Earthquakes

(April 14) -- Hardly a week has gone by lately without news of another powerful earthquake somewhere in the world. Although scientists say the rash of quakes is not unusual, Wednesday's disaster in western China is the latest reminder of the risk for anyone living near a fault line.

Nerves were already on edge in Southern California because of a rumor that swept through the Los Angeles area Monday. Word spread by e-mail, Twitter and other social networks that a major quake would hit the city in the next few days. Seismologists scrambled to shoot down the hoax, explaining that there's no way to make such a precise forecast. Some suspect the rumor was linked to QuakePrediction.com, which warned of a "very high risk" that a "significant" earthquake would hit the region within days. The Web site is run by Luke Thomas, who's been labeled a "Quake Quack," according to the Orange County News.

Southern California has been rattled by 70 earthquakes of magnitude 4.0 or higher so far this year, compared to 30 during all of last year. U.S. Geological Survey geophysicist Brad Aagaard explained that the 7.2 quake that struck Mexico's Baja California April 4 caused many strong aftershocks in the region. (Click to see map of latest California quakes.)

Worldwide, however, the number of major quakes recently is about average. In a normal year, there is one earthquake of magnitude 8 or higher and 17 from 7.0 to 7.9, according to the USGS.

Haiti's 7.0 earthquake on Jan. 12 is by far the deadliest of the year, taking more than 200,000 lives. The tragedy heightened worldwide sensitivity to the quakes that followed. The year's strongest is the 8.8 temblor that struck off the coast of Chile on Feb. 27, which killed more than 400 and triggered a series of powerful aftershocks.

The chart below shows the dates and strength of this year's biggest earthquakes.

Source:US Geological Service