(BIVN) – The eruption at the summit of Kīlauea volcano continued on Monday, with lava fountaining visible in the southwest portion of the caldera. 

The USGS Alert Level for Kīlauea is WATCH, and all activity is confined to the summit caldera within Hawaiʻi Volcanoes National Park. 

In its daily update, the USGS Hawaiian Volcano Observatory provided the latest instrumental and visible observations:

Summit Instrumental Observations: Seismicity at the summit over the last 24 hours has been low with one small detected earthquake. Seismic tremor remains has increased gradually over the past few days with the increase in fountaining. Summit tiltmeters recorded deflationary tilt over the past day. SO2 emissions remain elevated, with a gas plume rising above the caldera this morning and carried to the southwest.

Summit Eruption Observations:  Webcam images indicate that the eruption within Kaluapele (the summit caldera) continues this morning from vents on the southwest side of Halemaʻumaʻu crater. Effusion of lava over the past day has produced an enlarging fan of flows that cover the southwest portion of the crater, and have been advancing towards the central part of the crater floor. Yesterday morning, HVO geologists on the crater rim observed fountains reaching about 40 m (130 ft) high. This morning, HVO geologists in the field report fountain heights of around 30 m (100 ft).

USGS: “Several koa‘e kea birds (white-tailed tropicbirds) were flying circles above the Kīlauea summit eruptive vent on December 29, riding thermal updrafts from the lava pond.” (USGS photo by M. Patrick)

Rift Zone Observations:  Shallow earthquake counts on the East Rift Zone (ERZ) remain at low levels. Over the last 24 hours, there was one earthquake in the lower ERZ. The ESC tiltmeter on the upper part of the ERZ shows deformation associated with the recent eruption. Deformation rates remain low in the middle and lower ERZ and SWRZ as recorded by GPS instruments and tiltmeters. 

Analysis: The current eruption at the summit of Kīlauea is the sixth eruption within the caldera since 2020. These eruptions in the summit region have lasted for about a week to more than a year in duration. This eruption, like most others, started with vigorous lava and volcanic gas emission, but has paused twice and today shows moderate levels of activity. Current fountaining intensity has been associated with deflation of the summit magma reservoir, which in earlier episodes led to pauses in eruptive activity; it is uncertain if these fountaining levels will be sustained. Previous summit eruptions have exhibited vigorous activity in the opening days which can episodically wax and wane, or drop over time to sustainable low effusion rates, or slowly diminish and end.

USGS: “On December 29, Hawaiian Volcano Observatory geologists collected scaled video of lava fountaining as well as laser rangefinder measurements of fountain heights and crater floor elevations.” (USGS photo by M. Patrick)