HILO >>

A series of sharp, shallow earthquakes rattled the summit area of Kilauea volcano Wednesday morning, and the gray plume from an ash eruption at the summit crater continued to distribute volcanic ash as far away as Kau and Pahoa village.

The plume was only a fraction of what it was on Tuesday, but the Hawaiian Volcano Observatory still reported “occasional bursts of ash” from the crater.

The National Weather Service canceled its “ashfall advisory” at 8:33 a.m. Wednesday, but by early afternoon it was again reminding Hawaii island residents that light ashfall and hazardous air quality were possible as light winds pushed particles and gases from the eruption around the eastern and southern portions of the island.

A series of shallow but powerful earthquakes rocked the summit area Wednesday, and state Department of Transportation spokesman Tim Sakahara said a magnitude 3.5 earthquake at 11:31 a.m. opened “minor cracking” on Highway 11 — also known as Hawaii Belt Road or Volcano Highway — near the entrance of Hawai‘i Volcanoes National Park.

Police said the cracks were between mile markers 28 and 29, but Sakahara said the road is “open and safe.” Hawaii Civil Defense Agency Administrator Talmadge Magno said the highway has a 2-inch vertical separation and a 1-inch gap, and state highways crews plan to “mill down” the asphalt to even out the surface of the road.

Data from the U.S. Geological Survey showed there also was a 4.4 magnitude earthquake near the summit at 8:30 a.m. Wednesday, followed by a series of temblors that included magnitude 3.9, 3.5 and 3.7 earthquakes in the area during the following 15 minutes.

Michelle Coombs, a research geologist with the U.S. Geological Survey, said the summit earthquakes are being caused by deflation as underground magma that was stored beneath the summit drained off, and apparently fed into the ongoing eruption in the Lower East Rift Zone about 25 miles away.

That loss of magma has caused the floor of the crater to drop 3 feet, causing the ground to crack and shallow but powerful earthquakes, she said.

Magno said the water system of the Hawai‘i Volcanoes National Park reportedly suffered some damage in the earthquakes, but the park was closed at the time.

Park remains closed

Hawai‘i Volcanoes National Park has been closed for five days to protect the public from explosions that could be triggered as the magma level in Halemaumau Crater drops below the level of the water table. As water enters the superheated lava conduit, it flashes into steam.

If the conduit then becomes blocked by falling rocks or debris, that could cause blasts similar to those during a 1924 eruption, which featured 2-1/2 weeks of explosions. Ash and debris were tossed into the air, and experts say such those explosions can hurl boulders more than a half-mile.

Scientists at the summit Wednesday morning discovered rocks of up to 2-feet across that had been tossed from the crater into a parking lot several hundred yards from Halemaumau, which “reflect the most energetic explosions yet observed and could reflect the onset of steam-driven explosive activity,” according to USGS.

About 25 staff members from the USGS Hawaii Volcanoes Observatory have moved out of the observatory facility at the summit — most of them on Wednesday — because of the earthquake activity. Those scientists are now working from offices at the University of Hawaii at Hilo that were prepared for them in recent weeks, Coombs said.

She said the summit earthquakes have caused some damage at the observatory itself including “some cracking, and that’s still being assessed, the level of that and the severity of that at the observatory.”

Hara takes on dual duties

In Honolulu, Gov. David Ige announced Secretary of Defense James N. Mattis approved his request Wednesday to appoint Brig. Gen. Kenneth Hara as the head of a formation of a “dual-status command Joint Task Force 5-0” in response to the eruption.

Hara is the deputy adjutant general and commander of the Hawaii Army National Guard, and that arrangement gives him the authority to command both National Guard and active military forces to carry out operations such as a mass evacuation if roadways in Puna are blocked or destroyed by lava, according to a statement from Ige’s office.

“I thank Secretary Mattis for his quick approval,” Ige said in a written statement. “This joint military task force will provide the necessary state and federal resources to Mayor (Harry) Kim and his Civil Defense team. Together, we are committed to supporting the residents of Hawaii Island in their time of need.”

A 22-member advance team has deployed to the Keaukaha Military Reservation in Hilo to began planning for potential missions, according to the announcement.

Hara told reporters the dual- status command arrangement makes it possible for him to request support, including equipment such as helicopters from active duty military across the state and help from some of the 1,200 soldiers now training at the Pohakuloa Training Area on Hawaii island.