U. S. Geological Survey
A 5.0 magnitude earthquake on Thursday rocked several communities on the Big Island that are already bracing for a possible volcanic eruption after hundreds of small earthquakes jolted the region.
The Hawaiian Volcano Observatory said the quake, which struck at 10:30 a.m., “caused rockfalls and possibly an additional collapse” into the Pu’u ‘Ō’ō, a crater on the Kilauea Volcano that has been slowly crumbling.
A pink plume of ash could be seen briefly wafting over the crater but no other significant changes had been observed, HVO said on its website.
U.S. Geological Survey
Geologists say the ongoing temblors — more than 600 in the last three days — are an indication that lava could break through the surface at any time.
Most of the quakes have been in the magnitude-2.0 range and until Thursday morning, the largest recorded was a 4.2 magnitude.
The agency that operates the county’s emergency preparedness and response program has warned residents to prepare for evacuation in case of an eruption.
“A lava breakout remains a possibility and it could happen quickly,” Janet Babb, an HVO geologist told NPR, adding that these types of events are nearly impossible to predict.
Babb explained that the rumbling in the region goes back to mid-March when the cone of the Pu’u ‘Ō’ō crater began to swell and the pressure trapped inside caused the crater floor to collapse on April 30. That forced an intrusion of the magma, which means that rather than gushing upward through the crater of the volcano, it starting seeping underground.
As it moves beneath the surface, the molten lava is breaking up rock and causing the ground to shift. That process results in earthquakes. And the fear is that lava will spew out of cracks created by those earthquakes and destroy nearby homes.
U.S. Geological Survey
Since Monday the magma has moved under major highways and also to a neighborhood called Leilani Estates, nearly 25 miles from the Kilauea Volcano.
Hawaii News Now reported several quakes Wednesday “created cracks in the roadway,” measuring up to 18 inches long and 2 inches wide in some places.
National Park Service officials have shut down 16,000 acres of the Hawaii Volcanoes National Park as a precaution. And a local charter school was also closed on Thursday.
Babb compared this week’s volcanic activity to an eruption of Kilauea in 1955 that lasted 88 days and covered about 3,900 acres in lava destroying nearby communities.