POSTED: 2:33 p.m. HST, Oct 19, 2011
LAST UPDATED: 6:17 p.m. HST, Oct 19, 2011
A 4.5-magnitude earthquake rattled the Big Island this afternoon, but so far no damage or injuries have been reported, the Hawaii Island Civil Defense said.
The quake happened at 2:13 p.m. in Waikoloa and was too small to cause a tsunami, according to the Pacific Tsunami Warning Center in Ewa Beach.
The Waimea headquarters of the Keck Observatory was briefly evacuated, said communications officer Larry O'Hanlon. He said the main quake was followed by several aftershocks. He said engineers determined there was no damage at the observatory atop Mauna Kea, where the quake also was felt.
The quake was centered about six miles northwest of Mauna Kea's summit, according to Hawaii Island Civil Defense. About 15 aftershocks, with magnitudes ranging from 2.0 to 3.6 were recorded in the hour since the quake.
John Drummond, Hawaii island civil defense administrative officer in Hilo, said some people in the office felt a light shaking. About a dozen people called wanting to know how large the quake was, but didn't report any damage.
The initial quake was about 12 miles deep and 13 miles southeast of Waimea, according to the U.S. Geological Survey. It was felt throughout Hawaii island, according to reports from the public compiled by the USGS.
"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 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 today'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.
The Associated Press contributed to this story.