A magnitude 4.5 earthquake shook the Big Island early Saturday morning.
The U.S. Geological Survey said the quake happened at 2:18 a.m. Wes Thielen, seismic network manager at the U.S.G.S. Hawaiian Volcano Observatory said the quake was centered about five miles north of Naalehu in the Ka’u District at a depth of six miles.
The quake apparently woke up a lot of people on the Big Island. The U.S.G.S. said it received more than 70 reports from people within an hour after it happened.
Three aftershocks of magnitudes 1.6, 1.5 and 1.4 were recorded as of 3:30 a.m. Geologists said additional aftershocks could be possible.
Geologists said over the past 30 years, the area north of Naalehu has experienced six earthquakes of magnitudes greater than 4.0. This area of Ka’u is a seismically active region where a magnitude 6.2 earthquake occurred in 1919. Areas near the latest quake experienced earthquakes of magnitudes 6.0, 7.1 and 7.9 in 1868.
It’s believed that the quake happened on the large fault plane between the old ocean floor and the overlying volcanic crust, which is a common source for earthquakes in the area.
Geologists also said the earthquake didn’t cause any detectable changes in the ongoing eruptions at Kilauea Volcano or any of the other active volcanoes on the Big Island. A magnitude 3.1 earthquake at Kilauea caldera was recorded one minute before the 4.5 earthquake, but is unrelated, geologists said.
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