GPS key to monitoring Kilauea eruption, lava lake

2020 Ends with a Bang as Kilauea Volcano Erupts

Beginning in September, GPS stations in Kilauea’s upper East Rift Zone observed increased rates of uplift, higher than they have been since the end of the eruption in 2018. According to the U.S. Geological Survey’s Hawaiian Volcano Observatory, earthquake rates increased in late November.

On Dec. 2, GPS stations and tiltmeters recorded a ground deformation quake at Kilauea’s summit accompanied by earthquake swarms.

Then on Sunday, Dec. 20, a magnitude 4.4 earthquake struck on Kilauea’s south flank and three fissure vents broke open inside the caldera. Fountaining lava at these vents is estimated to be up to 82 feet high. The vents are feeding lava flows into the base of Halema‘uma‘u crater, which is being filled with lava. The lava lake has been rising several yards an hour since the eruption began at 9:36 p.m. Sunday. The eruption is currently confined to the crater.

According to the observatory, “The water lake at the summit of KIlauea has boiled away and an effusive eruption has commenced, with three vents in the wall of Halema‘uma‘u crater generating lava flows that are contributing to a growing lava lake at the base of the crater.”

As of Dec. 29, the summit eruption continued with the western vent active (the other vents have been covered by the lava lake). At 3:45 a.m. HST, field crews measured the lava lake as 179 meters (587 feet) deep, about 650 feet below the rim.

Shortly after 9:30 p.m. HST Dec. 20, an eruption began at the summit of Kīlauea Volcano in Hawaii. Red spots indicate fissure vents feeding lava into the bottom of Halema‘uma‘u crater. Lava coverage is 32 feet higher than the water in this photo (base map is from imagery collected on Sept. 23, 2020).

The water lake at the base of Halema‘uma‘u crater has been replaced with a growing lava lake. View from the west rim of Kīlauea Caldera just before 5 a.m. HST on Dec. 21, 2020. A 59-foot fountain joins two other fissures to feed a growing lava lake at the base of Halema‘uma‘u crater. (Photo: USGS)

The interactive USGS monitoring map shows GPS stations situated on and around Kilauea as well as volcano activity. (screenshot taken at 12 p.m. HST on Dec. 21).

An HVO geophysicist deploys a GPS receiver on the Kilauea caldera floor to measure changes in ground motion. A volcanic gas plume rises in the background. GPS and tiltmeter data show contraction in the upper portion of the East Rift Zone (an area between Kīlauea’s summit and Pu‘u ‘Ō‘ō). (Photo: USGS)