Volcano Activity Update: May 4, 2017

The episode 61g Kamokuna ocean entry has been slowly building a new lava delta for a little over a month now. Since our April 15 post, the delta has grown substantially. Two large cracks parallel to the coast are visible on the delta (center), with the distal portion slumping slightly seaward—suggesting further instability. Today, the ocean entry activity, most of which was located along the western side of the delta and obscured by the thick plume, was producing occasional weak littoral explosions. April 27, USGS/HVO photo.

This past week, Kīlauea Volcano’s summit lava lake level fluctuated in concert with summit inflation and deflation, ranging 49 to 105 feet below the vent rim.

On the East Rift Zone, the 61g flow was still active, with lava entering the ocean near Kamokuna and surface breakouts downslope of Pu‘u ‘Ō‘ō.

These flows do not pose an immediate threat to nearby communities.

On May 3, the front section of the Kamokuna lava delta collapsed into the sea, a reminder that new land created by ocean entries is highly unstable and prone to collapse without warning.

Mauna Loa is not erupting.

GPS measurements continue to show deformation related to inflation of a magma reservoir beneath the summit and upper Southwest Rift Zone. No significant changes in volcanic gas emissions were measured.

During the past week, small-magnitude earthquakes were recorded primarily beneath the upper Southwest Rift Zone at depths up to 3 miles and the upper west flank at depths of about 4 to 5 miles. A magnitude-3.1 earthquake occurred in the upper Southwest Rift Zone on April 28.

One earthquake was reported felt on the Island of Hawaiʻi during the past week. On May 3, at 1:32 p.m. HST, a magnitude-3.2 earthquake occurred 1.8 miles south of Kīlauea’s summit at a depth of 1.7 miles.