The USGS Hawaiian Volcano Observatory issued an information statement on Friday evening reporting elevated unrest and increased seismicity to the south of Kīlauea’s summit. The HVO reports that Kīlauea is not erupting, but that the increased unrest started at around 1:10 p.m. on Friday, Dec. 29, 2023, and is continuing.
The seismicity followed a sharp increase in the rate of inflation on the Sand Hill tiltmeter that began at 12:30 p.m. HST on Dec. 29, and is continuing. The increased seismicity began just to the south of Halemaʻumaʻu and has progressively included a larger region to the south of the caldera about 2–4 km (1–2.5 mi) south of Halema‘uma‘u crater.
The seismicity is occurring at depths of 1–3 km (0.5–2 mi) with magnitudes ranging from a maximum of 2.5 to less than 1. There have been more than 80 locatable earthquakes in this region within a 6 hour period, and many smaller earthquakes.
“The summit of Kīlauea remains at a high level of inflation and eruptive activity at the summit is possible with little or no warning,” according to the HVO. Scientists say there has been no unusual activity noted along Kīlauea’s East Rift Zone or Southwest Rift Zone. The current Volcano Alert Level remains at ADVISORY. The current Aviation Color Code remains at YELLOW.
The most recent eruption at Kīlauea summit ended on Sept. 16, 2023, but was followed by a significant intrusion to the southwest of Kīlauea caldera. Seismicity has waxed and waned since then alternating between the southwest area, the south end of the caldera, and the upper East Rift Zone. Most recent seismicity has alternated between the summit caldera and the upper East Rift Zone, according to the HVO.
The HVO reports that “earthquake swarms like this can precede eruptions, but there is no lateral or upward migration of earthquakes that would suggest magma is moving toward the surface at this time.”
“There are currently no signs of an imminent eruption at Kīlauea, but the volcano’s summit region remains unsettled, with a high level of inflation and continued seismic activity,” according to the HVO.
HVO continues to closely monitor Kīlauea volcano, watching for any signs of accelerated rates of earthquakes or ground deformation, or signs of shallowing earthquake locations, which usually precede a new outbreak of lava or propagating dike. The agency is also closely monitoring gas emissions and webcam imagery.
· S2cam: https://www.usgs.gov/observatories/hvo/s2cam-kilaueas-upper-southwest-rift-zone-looking-southwest
· MITDcam: https://www.usgs.gov/observatories/hvo/mitdcam-kilaueas-upper-southwest-rift-zone-looking-north