Volcano Activity Update: May 25, 2017

The lava delta at Kīlauea Volcano’s Kamokuna ocean entry continues to grow. On May 23, activity was concentrated near the southeastern tip of the delta, creating a thick steam plume that afforded only occasional glimpses of lava entering the ocean. Small littoral bursts were common as molten lava interacted with the cool seawater. Many narrow cracks parallel to the sea cliff could be seen on the delta surface. USGS photo.

This past week, Kīlauea Volcano’s summit lava lake fluctuated in concert with summit inflation and deflation, with levels ranging around 56 to 115 feet below the vent rim.

On the East Rift Zone, the 61g flow remained 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.

GPS measurements continue to show deformation consistent with 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, mostly from beneath the volcano’s summit caldera and upper Southwest Rift Zone at depths up to 3 miles. Microearthquakes also occurred on the east flank at depths of 3 to 8 miles.

Two earthquakes were reported felt on the Island of Hawaiʻi during the past week. At 7:28 a.m. on May 22, a magnitude-3.3 earthquake occurred 7.7 miles north of Nā‘ālehu at a depth of 6.6 miles. At 11:15 a.m. on May 18, a magnitude-3.2 earthquake occurred 6.6 miles west of Kalapana at a depth of 4.5 miles.

The Volcano Activity Update is a weekly article written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates.

Call for summary updates at (808) 967-8862 (Kīlauea) or (808) 967-8866 (Mauna Loa); email questions to [email protected].