Hawaiian Volcano Update: Kīlauea South Caldera Earthquakes Increasing
Earthquake rates doubled this past week beneath Kīlauea’s south caldera and deeper under its summit, indicating ongoing magma movement and accumulation within the volcano’s underground reservoirs. Overall seismic levels are still low relative to the build-up ahead of prior intrusions and eruptions, and there are no signs of an eruption within the short term as Kīlauea continues to recover from its massive Southwest Rift intrusion on January 31.
Recent earthquakes and ongoing ground deformation measured by GPS suggest this recent Southwest Rift pathway remains active and magma is still being fed into the lower parts of the rift zone. Deeper earthquake flurries have also increased in frequency and intensity beneath the summit, likely reflecting an active magma supply into the shallower parts of the volcano. In those shallower regions, the highest clustering of events between 0.5 and 1.0 miles below sea level suggests a nexus of magma accumulation beneath the south caldera even as magma continues to move into the Southwest Rift connector from there. Volcanic gas emissions, the main current threat to residents and visitors, remain relatively low around 100 tonnes of SO2 per day, still a concern for sensitive individuals nearby.
Maunaloa’s story continues to be one of recharge following its 2022 eruption, overall remaining quiet with few earthquakes and sustained slow inflation. Deep earthquakes beneath Maunaloa began with a small flurry less than 5 months following the end of its eruption, built up to a large swarm in November 2023, and have been more sporadic since. The most recent deep quake swarm last month appears to have subsided again thus far this month.
As usual we review the monitoring signals, imagery and reports available courtesy of the USGS Hawaiian Volcano Observatory, annotating the presentation on screen as we go and discussing live viewer questions. As a bonus this week, we present a shortened recap and review of the USGS presentation on “Multi-platform mapping of active lava flows at Hawaiian volcanoes” from Volcano Awareness Month in January 2024.
