Lava Fountaining Slows in Halemaʻumaʻu Crater

8:23 AM HST Tuesday, Jan. 12, 2021: USGS Hawaiian Volcano Observatory

Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Around sunset on Saturday (January 9, 2021), a break in the rain allowed HVO scientists to visit and monitor the ongoing eruption in Halema‘uma‘u. The west vent is still actively effusing lava, but outflow into the lava lake is increasingly sluggish, as evidenced by slow-moving crustal plates near the once-vigorous vent outlet. Also, much of the crust in the eastern half of the lake has stagnated completely, likely because the lake level has not changed significantly in the past three days. USGS photo by H. Dietterich.

The lava lake at Halemaʻumaʻu crater is now 643 deep below the west vents. As of this morning, the west vents showed low fountaining that fed lava flows and channels from the top of small cones plastered on the northwest wall of Halemaʻumaʻu crater into the lake.

SO2 emission rates were still elevated. Summit tiltmeters recorded continuing inflationary tilt. Seismicity remained elevated but stable, with steady elevated tremor and a few minor earthquakes.

There is no seismic or deformation data to indicate that additional magma is currently moving into either of Kīlauea’s rift zones. SO2 and H2S emissions from Puʻu ʻŌʻō were below instrumental detection levels when measured on Jan. 7.

The eastern vents are currently stagnant and 4 yards shallower than the west vents. The eastern part of the lake appeared to have subsided below its perched rims. Overall, the dimension of the active and inactive parts of the lake remained the same. The lake was still perched at least 1-2 yards above the inactive crust between the perched lake and the crater wall which was also rising.

All islands were stationary over the past two days as if frozen in the eastern stagnant portions of the lava lake. The dimensions of the main island remained unchanged with its edges several yards above the lake surface. On Jan. 8, the west end of the island was measured as 10 yards with the high point 25 yards above the lake surface.