Hawaiian Volcano Update: Strongest Swarm Marks Kīlauea’s Latest SW Rift Intrusion

For most of January, Kīlauea’s earthquakes slowed significantly as magma continued to gather underground, but during the past week the volcano reached a breaking point, starting on January 27th as its south caldera seismicity resumed. This preceded a significant pulse of magma that triggered the largest number of earthquakes in this sequence since its start in October, exceeding 1,500 located events thus far.

The big pulse began in the south caldera two nights ago and has migrated down the Southwest Rift Connector about 10 miles to Puʻu Kou on the Southwest Rift thus far. While the situation has not yet stabilized, the sequence closely resembles that of early October as we await any further developments. The latest USGS-HVO update states that “based on past historical activity, this event is much more likely to continue as an intrusion, but there is still a possibility of it ending in an eruption.”

Most intriguing is the summit and south caldera’s ongoing drop in ground tilt, logging nearly 50 microradians thus far (perhaps 10% of the 2018 signal). This suggests that magma is still actively leaving the summit region to feed the intrusion, meaning that pressure in downrift areas could increase over the coming days. Combined with shallower earthquakes than usual in the Connector, a breakout of lava down the Southwest Rift is still in play. With potentially slack winds in the summit area, “strong degassing could impact areas of Hawaiʻi Volcanoes National Park and surrounding communities if an eruption does occur in the summit region” and so it is past time for nearby residents to prepare. For now, gas emissions remain at background levels for the volcano around 70 tonnes of SO2 per day, but can still affect sensitive individuals downwind.

Maunaloa remains relatively quiet with few earthquakes, with slowing inflation as it recharges with magma, and remains at the lowest USGS warning level.

As usual, we review the monitoring signals, imagery and reports available courtesy of the USGS Hawaiian Volcano Observatory, annotating the presentation on screen and discussing live viewer questions as we go. To support our productions please like, share and subscribe, and consider making a donation at https://hveri.org/donate .