Hawaiian Volcano Update: Maunaloa Quakes Decrease, Kīlauea Lava Lake Wanes

Over the past 4 days, Maunaloa's earthquakes have once again decreased to their recent elevated background rates of 10-20 per day, but further variations seem likely. A similar drop occurred just over one month ago, the lull lasting 5 days before increasing back to 40-50 earthquakes per day for the 4 weeks since. Other monitoring data have continued their trends suggesting deeper magma input into the volcano, over 2 miles (3 km) below the surface, with no shallower signals since early October. As magma continues to build within, it is typical for Maunaloa to periodically adjust in fits and starts. A large enough adjustment could escalate into an eruption, but so far the observed activity still “does not suggest that a progression to an eruption is certain, and there are no indications that an eruption is imminent.” On Kīlauea, the visible lava lake level has dropped by about 3 ft (1 m) in the past week, coincident with back-to-back deflation-inflation cycles evident in the ground tilt and a low SO2 emission rate of 350 tonnes per day. Less gas emitted means less vog for downwind communities, which still remains the primary eruptive hazard. GPS measurements show contraction across the summit caldera that suggest less magma accumulation, but accompanied by increased south flank motion that could reduce pressure around the summit by slightly widening the magma reservoir network. Overall this pattern is not a significant change, but part of the ongoing evolution of Kīlauea's magmatic system, with no increased threat to people. These subsurface adjustments make it difficult to gauge any change in magma input into the volcano, but regardless it seems less lava is reaching the surface despite the persistence of the surface lava lake. That persistence means great lava viewing is still possible for visitors to Hawaiʻi Volcanoes National Park, who each see a unique snapshot of all the little features of the changing landscape. A recent publication by Przeor and others (2022) in Nature explores the near-surface elastic interaction between Maunaloa and Kīlauea, and suggests that shallow inflation of Maunaloa can constrict the shallow magma network on Kīlauea, but not the other way around. The current situation could potentially be described by this interaction, in addition to the previously modeled relation between the volcanoes through deep pressure transfer described by Gonnerman and others (2012). As usual, we review the changes through imagery, reports and monitoring data courtesy of the USGS-HVO, discuss live viewer questions, and annotate the presentation on-screen as we go. Live: https://youtu.be/i-Bv6zd0XYQ