Earthquakes beneath Kīlauea summit dramatically decrease

The major intrusive event that has been ongoing beneath the southern part of Kīlauea’s summit caldera extending southwest to the Koaʻe fault zone appears to have slowed significantly.

According to Hawaiian Volcano Observatory, there has been a dramatic drop in earthquakes, from a peak of over 250 per day last week to only 23 recorded in the past 24 hours, which suggests the intrusive event is coming to an end. These earthquakes were at depths of 0.6 to 3 miles beneath the surface.

These observations suggest that new magma supply to the intrusion below the surface south of Kīlauea’s summit caldera has slowed greatly. However, inflation at the summit of Kīlauea remains high and has nearly returned to the level seen just before the last eruption on Sept. 10.

Currently, 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, is showing a flat tilt trend. Sulfur dioxide emission rates remain low and were measured at a rate of about 100 tonnes per day on Oct. 6. Other monitoring data streams, including webcam views, do not show any significant changes.

Inflation at the summit of Kīlauea remains high, and seismicity and ground deformation rates are likely to begin increasing again in the near future.

No unusual activity has been noted along the East Rift Zone or Southwest Rift Zone.