Strong 6.0 Quake Hits Offshore California
Quake Centered 35 Miles Offshore; Shaking Felt in Eureka, but No Injuries or Damage Reported
related: 6.5 Quake Rattles Eureka in Northern California
...Multiple Aftershocks, No Tsunami
February 4, 2010
San Jose Mercury News
A 6.0 earthquake struck about 35 miles off the coast of Northern California this afternoon, about one month after a major quake off the coast rocked the communities along California's rugged northern coast.
The USGS said Thursday's temblor occurred at 12:20 p.m. about 47 miles west southwest of Eureka. There were no immediate reports of damage, and officials say the magnitude of the quake was not expected to trigger a tsunami.
Humboldt County spokesman Phil Smith-Hanes says he felt a rolling sensation, but the movement didn't feel as severe as the magnitude-6.5 quake that struck last month.
The earthquake follows a larger 6.5 temblor that struck Jan. 9, which caused an estimated $12.5 million structural damage to the picturesque city of Eureka, with 14 residents displaced.
This is the seismic capital of the state, one of the few places in the world where three gigantic tectonic plates merge. Because of the different directions and various rates of movement of the plates, the area absorbs great geologic strain and often fractures. Historic research shows that every 300 to 400 years, the region experiences a huge quake in the range of about 9 magnitude.
The earthquake that leveled the capital of Haiti measured 7.0. But because Northern California is rural, with a scattered population residing in wood frame housing that is built to code, this region's earthquakes tend to be much less devastating.
As with any large earthquake, there is a possibility of damaging aftershocks.
From USGS
Magnitude 6.0 - regional moment magnitude (Mw)
Time Thursday, February 4, 2010 at 12:20:21 PM (PST)
Thursday, February 4, 2010 at 20:20:21 (UTC)
Distance from Petrolia, CA - 56 km (35 miles) WNW (282 degrees)
Ferndale, CA - 59 km (36 miles) WSW (254 degrees)
Fortuna, CA - 68 km (43 miles) WSW (256 degrees)
Eureka, CA - 76 km (47 miles) WSW (239 degrees)
Sacramento, CA - 363 km (225 miles) NW (306 degrees)
Coordinates 40 deg. 25.8 min. N (40.431N), 124 deg. 55.8 min. W (124.929W)
Depth 11.2 km (7.0 miles)
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