Hawai‘i Volcano Activity Update: Sept. 28, 2017

Clear views at the ocean entry: A weak plume on Sept. 26 on the far (west) side of the delta provided great views of changes at the ocean entry. Over the past few weeks there have been repeated breakouts on the delta which have resurfaced over half of the roughly 10 acre delta, as mapped on Sept. 21. Many of the large delta cracks have been completely or partially covered by flows, but hazards at the ocean entry have not changed. On the far right cliff horizon, a thin silver flow that started on Sept. 23, 2017, is just visible. USGS/HVO photo.

This past week on Hawai‘i Island, Kīlauea Volcano’s summit lava lake (Halemaʻumaʻu) level fluctuated with summit inflation and deflation and ranged about 112 to 174 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.

Active lava flows and a small collapse were observed on the Kamokuna lava delta this week and it remains unstable with potential for larger collapses.

The 61g flows do not pose an immediate threat to nearby communities.

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 continued to occur beneath the summit caldera and upper Southwest Rift Zone, primarily at depths less than 3 miles, with some additional deeper events at 3 to 8 miles deep.

No earthquakes were reported felt in the Hawaiian Islands during the past week.

The “Hawai‘i 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 askHVO@usgs.gov.