HVO: Pressure building under Kilauea’s Pu’u ‘O’o vent

Hawaiian Volcano Observatory geologists in Sept. 2017 change data cards on a time-lapse camera positioned on the rim of the west pit within Pu‘u ‘O‘o Crater. (US GEOLOGICAL SURVEY
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HILO — Geologists say a new vent could open at the Pu‘u ‘O‘o cone or along adjacent areas of Kilauea’s East Rift Zone as pressure continues to build underneath.

The Hawaiian Volcano Observatory issued a notice Tuesday that there has been pronounced inflation of the cone since mid-March, which suggests a buildup of magma at shallow depths. Recent webcam images detected uplift on the Pu‘u ‘O‘o crater floor of several yards.

“It is possible a part of the rift zone nearby Pu‘u ‘O‘o within a few kilometers could be affected, but, most likely, it’s going to be at the cone,” said Steve Brantley, HVO deputy scientist-in-charge.

Pu‘u ‘O‘o has been erupting almost continuously since 1983, but a buildup in pressure can lead to a change in flow direction, depending on where on the cone a new vent emerges, assuming one does.

Brantley said similar activity was seen before the start of the “June 27th” flow in 2014 and the ongoing “61g” event that started in 2016.

The June 27th flow traveled 12.4 miles, reaching Pahoa to the northeast. One home was destroyed and lava entered a cemetery. The flow stopped short of Highway 130, the lifeline for thousands of residents.

Lava has been directed to the south or southeast since the 61g flow began.

Currently, there are scattered lava breakouts about 1.4 miles and 3.1 miles from the cone.

If a new vent emerges, it will take time to determine what path the flow will take, Brantley said.

Meanwhile, at the summit, the lava lake was about 36 feet below the Overlook crater rim on Tuesday morning.

Numerous small earthquakes were detected under the summit Tuesday, according to HVO’s website. Several such quake swarms have been recorded during the past few months, indicating movement of magma through the system.

Brantley said HVO is not anticipating a change in the summit eruption, though that area also has seen increased pressure during the past month.

Email Tom Callis at tcallis@hawaiitribune-herald.com.