Time-lapse thermal image movie of Halemaumau Overlook Vent. August 31-September 7, 2017. Images courtesy of USGS/HVO

Time-lapse movie of Halemaumau Overlook Vent. August 31-September 7, 2017. Images courtesy of USGS/HVO

Time-lapse movie of Halemaʻumaʻu Overlook Vent from Hawaiian Volcano Observatory. August 31-September 7, 2017. Images courtesy of USGS/HVO

Time-lapse movie of KÄ«lauea Caldera from Hawaiian Volcano Observatory. August 31-September 7, 2017. Images courtesy of USGS/HVO

Time-lapse movie of Halemaumau Crater looking Southwest. August 31-September 7, 2017. Images courtesy of Hawaii Volcanoes National Park

(Activity updates are written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

This past week, Kīlauea Volcano’s summit lava lake level fluctuated in concert with summit inflation and deflation, ranging about 16.5–31.5 m (54–103 ft) 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. Widening cracks and slumping on the Kamokuna lava delta indicate its instability and potential for collapse. The 61g flows do not pose an immediate threat to nearby communities.

Mauna Loa is not erupting. During the past week, small-magnitude earthquakes continued to occur beneath the summit caldera and upper Southwest Rift Zone, primarily at depths less than 5 km (3 mi), with some additional deeper events (5–13 km, or 3–8 mi). 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.

Two earthquakes with three or more felt reports occurred on the Island of Hawaiʻi during the past week: On September 6, at 1:40 a.m. HST, a magnitude-3.3 earthquake southwest of Pepeekeo at 30 km (19 mi) depth. On September 1, at 5:12 a.m. HST, a magnitude-2.6 earthquake northeast of Hawaiian Ocean View at 5 km (3 mi) depth.

Please visit the HVO website (https://volcanoes.usgs.gov/hvo) for past Volcano Watch articles, volcano updates and photos, recent earthquake info, and more. Call for summary updates at 808-967-8862 (KÄ«lauea) or 808-967-8866 (Mauna Loa). Email questions to askHVO@usgs.gov.

Time-lapse movie of Pu’u ‘O’o Crater. August 31-September 7, 2017. Images courtesy of USGS/HVO

Time-lapse image movie from a research camera positioned on Holei Pali, looking east towards Lava Flow 61G and Kalapana. August 31-September 7, 2017. Images courtesy of USGS/HVO