The Hawaiian Volcano Observatory (HVO) detected an earthquake swarm beneath the summit of Kilauea volcano, which could (but not necessarily must) herald a possible change in eruption style:
„On Wednesday, January 14 at 7:35 p.m. HST, a swarm of earthquakes began beneath Halemaʻumaʻu crater at the summit of Kīlauea. Elevated seismic activity gradually died down in frequency of occurrence and intensity, over the course of 40 minutes. Locations of these earthquakes are spread broadly beneath east side of Halemaʻumaʻu crater and the south caldera. All of the detected earthquakes have been less than magnitude-2, with most being magnitude-1 or smaller.
This is the third small swarm of earthquakes beneath Halemaʻumaʻu crater since the end of episode 40. The first swarm began at 12:40 a.m. HST and lasted for 30 minutes on Tuesday, January 13. It was followed the next day by a second swarm around 9:10 a.m. HST, and lasted less than 30 minutes on Wednesday morning, January 14. The first and second swarms both had magnitude ranges similar to the third. Most of the earthquakes seem to be occurring around the shallow Halemaʻumaʻu magma chamber, some 1.5 to 4 km beneath the surface.
Most of the earthquakes are volcano-tectonic earthquakes that accompany crack opening due to magmatic pressure. Elevated seismic activity of these intensities have not been seen at the summit since the start of the eruption in December 2024. A small swarm did precede a new fissure opening in the wall of the Halemaʻumaʻu crater just to the south of the vents, at the start of episode 30. It is yet to be determined if these swarms after episode 40 will have an impact on lava-fountaining activity at the surface.
Volcanic systems remain a complex balance of magmatic pressure and strength of the surrounding rocks. If the rocks weaken, one possible outcome is injection of a magma into a fracture creating a dike. If the magma breaches the surface a new vent might be created shifting the focus of the eruption. Historically, episodic fountain eruptions can cease when the magma supply is diverted in this manner.
Currently all of the activity remains beneath Kīlauea caldera and there is no observable evidence that magma is migrating away from this area. Both the east and the southwest rift zones remain quiet at this time.“
