125 earthquakes recorded south of Kīlauea summit in the past 24 hours

The area just south of Kīlauea’s summit continues to show signs of unrest with approximately 125 earthquakes recorded in the region over the past 24 hours, compared to about 100 earthquakes occurring over the previous day.

Elevated seismicity beneath Kīlauea summit region began Oct. 4 18 days after an eruption, which lasted only six days. No unusual activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

According to Hawaiian Volcano Observatory, the Kīlauea summit tiltmeter recorded very slight inflation over the past 24 hours. Inflation at the summit of Kīlauea remains at about its highest level in over 5 years and has nearly returned to the level seen just before the last eruption on Sept. 10. The tiltmeter located just south of the summit is experiencing technical issues that HVO is working to resolve.

Most of the earthquakes from the seismic swarm south of the caldera are at depths of around 1.5–2 miles below the surface. The trend of the seismic activity parallels, but is slightly south of the December 1974 eruption vents. Sulfur dioxide emission rates remain low and were measured at a rate of about 100 tonnes per day on Oct. 6.

Levels of volcanic gas — sulfur dioxide and carbon dioxide — can remain locally hazardous even though Kīlauea is no longer erupting. Sulfur dioxide gas emissions have greatly decreased; however, local concentrations of sulfur dioxide or hydrogen sulfide may persist in downwind areas, and residents may notice odors of these gases occasionally. Significant hazards also remain around Halemaʻumaʻu from crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public.

For discussion of Kīlauea hazards, see https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.

The Hawaiian Volcano Observatory continues to closely monitor Kīlauea volcano.