Monitoring instruments positioned at Kilauea Volcano’s summit on Monday recorded a steep deflation signal consistent with the onset of a deflation-inflation event.
Tiltmeters at the summit recorded the event starting at 8 a.m. Monday, according to the U.S. Geological Survey Hawaiian Volcano Observatory. Tiltmeters are used to measure tiny changes in the slope angle or “tilt” of the ground.
Scientists said Tuesday morning that the summit lava lake level, which had held steady for the past several days at about 115 feet to 130 feet below the rim of the Overlook crater, began to drop, as well. Summit tremor, which had also been steady and somewhat elevated, peaked as the summit tilt signal dropped, before decreasing as well.
During inflation, magma rises into the summit reservoir, according to the observatory. The summit reservoir enters the deflation portion of the cycle when the magma moves laterally into a rift zone and either erupts or is stored there.
The tiltmeter on the north flank of Puu Oo continues to show no significant tilt, according to HVO.
“It was a small event and kind of a short event. It looks like it’s already turning around from deflation back to inflation, but we won’t know for several more hours,” Babb said shortly after noon on Tuesday. “But, it was a small event, so we don’t expect any impact on the lava flows on the East Rift Zone.”
The U.S. Geological Survey Hawaiian Volcano Observatory on March 25 downgraded its alert level for Kilauea Volcano from a warning to a watch.
The observatory said the decision to lower the alert level from “warning” to “watch” was made because the lava flow nearest to the town of Pahoa has remained inactive in recent weeks. Further, officials said, it’s unlikely that the lava tube in the lower reaches of the flow could be reoccupied.
Lava activity on Tuesday remained limited to three areas of breakouts located in the vicinity of Kilauea’s Puu Oo vent. Scientists, viewing the flow using web cams, said they were located on then northern flank of Puu Oo, as well as near Puu Kahaualea, and about 3 to 4 miles northeast of Puu Oo.
Hawaii County Civil Defense on March 28 suspended its daily eruption and lava flow updates.