Sinking Big VOLCANO, Hawaii--Four moderate earthquakes that shook the Big Island earlier this week were likely caused by the ongoing settling of the Big Island and Mauna Kea, scientists said.
Isle causes earth-
shaking results
Scientists believe the isle's
settling caused recent
earthquakesAssociated Press
Although the four temblors were unrelated, they were all likely the result of the adjustment of the mountain or the earth's crust below, said Arnold Okamura, deputy scientist-in-charge at the Hawaiian Volcano Observatory.
"We have earthquakes on Mauna Kea fairly regularly," he said, "The mountain is pretty big and heavy."
The gradual sinking of the Big Island has been measured at more than one-tenth of an inch per year, scientists say. The rate is several times higher along the Puna coast, where lava from Kilauea continues to accumulate.
The strongest of the four earthquakes had a magnitude of 3.9. It occurred at 4:18 a.m. Monday at Pohakuloa between Mauna Kea and Mauna Loa, at a depth of about 19 miles. The observatory received calls of the quake being felt in Hilo, along the Hamakua Coast and in Waikoloa, Okamura said. There were no reports of damage.
On Tuesday there was a 3.1-magnitude quake in South Kohala and two quakes on Monday; 3.4 magnitude four miles east of Keaau and 2.8 magnitude 11 miles southwest of Honomu.
All magnitudes and depths, except for the 3.9 magnitude assigned to the Pohakuloa quake, are preliminary and awaiting verification, Okamura said.