Maunaloa Update: Summit Quakes Prompt Closure

Our primary focus shifts this week to Maunaloa, whose recent earthquake activity has prompted the USGS Hawaiian Volcano Observatory to switch from weekly to daily updates for the volcano, and Hawaiʻi Volcanoes National Park to close the backcountry area around Maunaloa summit. These are precautionary moves, but have created quite a stir in the community, thus offering an opportunity for us to share more of the scientific context. In short, the recent spike in activity has slowed, and fits into a pattern of magma intrusions into the summit and subsequent adjustments, last seen in August 2022, January to April 2021, late 2014 to 2015, and 2002 to 2005 prior to that. The USGS-HVO has repeatedly stated that “there are no signs of an imminent eruption at this time”, though the summit magma chamber continues to inflate, and changes can occur quickly. We review releases and monitoring signals available courtesy of the USGS-HVO, providing background on past activity and answering live viewer questions as usual. Given this week's special focus, we will postpone our catch-up update on Kīlauea until next week, as no major changes were evident over the past week. The volcano continues to generally swell, inflating with magma, filling its summit crater below its surface crust and circulating lava within its persistent lava lake, as evidenced in the main trends shown by summit tiltmeters and GPS stations. But over the past week, the typical smaller-scale cycles in surface deformation known as Deflation-Inflation events have dominated the short term signals. Yet the active lake depth has only fluctuated within a 5 foot or 1.4 meter range, and no ooze-up flows were observed from around the crater’s perimeter. Viewing for visitors to Hawaiʻi Volcanoes National Park remains good, with lava spattering within the lake and glow visible from the West Vent cones and pond. Gas emissions are back up near their recent average, with 1,800 tonnes of SO2 per day reported on September 30th. Vog to downwind communities remains the primary hazard of the eruption. For the near future, there remains no increased lava threat outside of the National Park. We are also deferring coverage of Taʻu volcano in American Samoa this week, where the seismic crisis appears to be ending. Full coverage will resume next week. https://youtu.be/XqxiSYvt7nM