Kilauea remains silent but monitoring network records signs of life

Kilauea offered up a hint of life earlier this month in a reminder that the volcano remains very much “active” following its historic 2018 eruption.

The U.S. Geological Survey’s Hawaiian Volcano Observatory reported this week that its volcano monitoring network recorded its first post-eruption magma intrusion at the Kilauea summit.

The small dike intrusion on Dec. 2 followed earthquake swarms on Nov. 30 and Dec. 2, as well as accelerated ground deformation recorded by tiltmeters in directions that differed from normal patterns.

HVO research geophysicist Ingrid Johanson said the swarms and pattern of ground deformation were consistent with a small dike intrusion under the southern part of Kilauea caldera.

A dike intrusion is an injection of magma into host rock that can sometimes occur prior to an eruption.

That is why an overnight watch was established at HVO to closely monitor the mountain, she said in HVO’s latest Volcano Watch column. But seismicity and deformation slowed down fairly quickly, and nothing else happened to indicate an eruption was imminent.

Johanson said models suggest the Dec. 2 intrusion was small, with about as much magma as erupted in just one to two hours from Fissure 8 in Leilani Estates during the 2018 eruption.

The intrusion is the latest sign of life recorded by HVO scientists following the 2018 lower East Rift Zone eruption, which was the last hurrah in a 35-year run of volcano activity at Kilauea. The eruption destroyed 716 homes in Lower Puna, forced the evacuation of 2,000 residents and caused damage estimated at more than $800 million.

Meanwhile, Kilauea’s USGS Volcano Alert level remains at normal.