Big Island rattled by earthquakes

By Hugh Clark
Advertiser Big Island Bureau

VOLCANO, Hawai'i — A pair of mid-sized earthquakes Wednesday shook the Volcano area of the Big Island but there were no reports of damage.

Seismologist Paul Okubo of Hawai'i Volcanoes Observatory said the first quake was a 4.6 magnitude at 5:37 p.m.

The second was a 4.2 magnitude aftershock, logged at 6:19 p.m.

There were smaller aftershocks. The quakes registered on National Park seismometers near the Namakani Paio Campground, west of the park headquarters.

They followed a series of Mauna Kea quakes, including a 3.9 magnitude April 15 near Pohakuloa.

Combined, this month has been the most seismically active in at least two years, said Okubo.

The strongest temblor Wednesday was the biggest single jolt on the island since April 16, 1999, when a 5.6 magnitude event in Pahala caused some structural damage to homes, destroying one residence.

Okubo said Wednesday's events had no impact on the ongoing eruption at Kilauea Volcano's southeast rift zone.

"This appears to be tectonic (a structural adjustment) rather than a volcanic event," he said.

Ka'oki fault, which has been among Hawai'i's most active during the last two decades, extends north and south in Ka'u while separating Mauna Loa Volcano from Kilauea.