Magnitude 5.7 quake hits Hawaii’s Mauna Loa volcano
HONOLULU (AP) – A magnitude 5.7 earthquake struck the world’s largest active volcano on Friday – Mauna Loa on the Big Island of Hawaii – knocking items off shelves and cutting power in a nearby town, but not immediately prompting reports of serious damage.
The earthquake, which didn’t cause a tsunami and which the US Geological Survey initially reported as magnitude 6.3, was centered on Mauna Loa’s southern flank at a depth of 37 kilometers, two kilometers southwest of Pahala.
“It shook us bad to where it wobbled some knees a little bit,” said Derek Nelson, the manager of the Kona Canoe Club restaurant in the oceanside community of Kona, on the island’s western side. “It shook all the windows in the village.”
There was a power outage affecting about 300 customers in Naalehu that appeared to be related to the earthquake, said Darren Pai, spokesperson for Hawaiian Electric Company.
The earthquake struck after 10 a.m. local time, less than two hours before an unrelated quake with a preliminary magnitude of 4.6 shook Southern California.
Mauna Loa last erupted in late 2022. It’s one of five volcanoes that make up the Big Island, which is the southernmost in the Hawaiian archipelago.
Earthquakes can occur in Hawaii for a variety of reasons, including magma moving under the surface. In Friday’s case, the Hawaiian Volcano Observatory said the likely cause was the weight of the Hawaiian Islands bending and stressing the Earth’s crust and upper mantle.
That’s what caused a magnitude 6.9 earthquake that struck off Kiholo Bay on the Big Island’s northwest coast in 2006. That temblor damaged roads and buildings and knocked out power as far away as Honolulu, on the island of Oahu, about 322 kilometers to the north.
Helen Janiszewski, an assistant professor in the University of Hawaii at Manoa’s Department of Earth Sciences, said the Hawaiian Islands lie on the Pacific oceanic tectonic plate and have some of the world’s biggest volcanoes.
“So, there’s a huge amount of mass of rock associated with the islands and because of that, it’s actually enough to slightly displace the Pacific oceanic plate beneath the islands,” she said.