Series of earthquakes strike Big Island of Hawaii

AP News
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Posted: Oct 19, 2011 10:52 PM
Series of earthquakes strike Big Island of Hawaii

A 4.5-magnitude earthquake struck the north part of the Big Island on Wednesday, and the shaking was followed by a series of smaller temblors.

The first quake struck 13 miles southeast of Waimea at about 2 p.m., the U.S. Geological Survey said. It was centered at a depth of 11.7 miles. About two dozen smaller quakes ranging in magnitude from 1.7 to 3.6 followed within two hours.

No tsunami alert was issued and there were no immediate reports of damage. Residents across the island reported feeling light to moderate shaking.

"When you feel a four-and-a-half at close range, it feels like a truck crashed into a building," said Weston Thelen, seismic network manager for Hawaiian Volcano Observatory.

The smaller quakes were normal sizes for an aftershock sequence, he said, adding that they can continue at low levels for several days.

The vast island _ spread across more than 4,000-square miles _ was formed by several volcanoes. The latest earthquakes caused no detectable changes in the continuing eruption of Kilauea volcano, according to the USGS Hawaiian Volcano Observatory.

Over the past 25 years, the north flank of Mauna Kea has experienced 10 earthquakes greater than magnitude 4.0, including Wednesday's event, at depths of 6 to 25 miles. Deep earthquakes in the region are most likely caused by structural adjustments within the Earth's crust due to the heavy load of Mauna Kea, the observatory said.

Adjustments beneath Mauna Kea during past similar events, such as in March 2010, have produced a flurry of earthquakes, with many small aftershocks occurring for days after the main quake.

A 6.7-magnitude earthquake that struck the Big Island on Oct. 15, 2006, damaged buildings and roads, but there were no serious injuries or deaths.