Unrest in the south summit area of Kīlauea could lead to an eruption

Unrest in the south summit area of Kīlauea continues with more than 110 earthquakes recorded in the region over the past 24 hours. No unusual activity has been noted along the East Rift Zone or Southwest Rift Zone.

According to Hawaiian Volcano Observatory, this episodic heightened unrest could lead to an eruption from the December 1974 vents during peaks in this current activity. The vents, located on the south end of the caldera and extending to the southwest, could emerge with as little notice as one to two hours.

Inflation at the summit of Kīlauea remains at about its highest level in over five years and has nearly returned to the level seen just before the last eruption on Sept. 10. The Uēkahuna summit tiltmeter located north of the caldera recorded very slight inflation over the past 24 hours.

The Sand Hill tiltmeter located just south of the caldera went off scale during the peak activity on Oct. 6, but has been reset and is showing continued inflation but at a lower rate than before the event. GPS units within the south end of the caldera and further south also show continued uplift of this region.

Seismicity increased on Oct. 4, peaked at over 250 earthquakes per day on Oct. 5 and 6, and continues dispersed over this area. Most of the earthquakes from the seismic swarm south of the caldera are at depths of around 1.5 to 2 miles below the surface. 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.