Unrest escalates at Kīlauea; more than 500 earthquakes rock upper East Rift Zone

More than 500 earthquakes have rocked Kīlauea beneath the volcano’s upper East Rift Zone — just southeast of the summit region — during the past 24 hours as heightened unrest associated with a seismic swarm that began June 27 continues.

But there are no signs of an imminent eruption.

Early this morning, seismicity in Kīlauea’s upper East Rift Zone, beneath Chain of Craters Road in Hawaiʻi Volcanoes National Park, intensified even further.

The Hawaiian Volcano Observatory reported in a Kīlauea Status Report at 1:43 a.m. today that rates of earthquakes had escalated to a peak of about 30 per hour by about midnight, most centered in the region between Puhimau Crater and the Hilina Pali Road intersection at depths of 1 to 1.8 miles and extending north toward Keanakākoʻi Crater and south to Pauahi Crater.

The largest of these earthquakes were four magnitude-3.0 events near the intersection between Chain of Craters Road and Hilina Pali Road in Hawaiʻi Volcanoes National Park, at similar depths to the rest of the swarm.

The observatory’s 8:24 a.m. daily Kīlauea update said the earthquake rate had eased slightly to about 20 earthquakes an hour, which still represents heightened unrest compared to before June 27.

Longer-term inflation of Kīlauea’s summit and upper rift zones has persisted since the end of the short-lived June 3 eruption, but there was no significant change in ground deformation associated with the increased seismicity.

Slowing inflationary tilt during the past few days transitioned to slight deflationary tilt, however.

Magma has been repressurizing the storage system beneath Halemaʻumaʻu and the south caldera region since the June 3 eruption, causing earthquakes in the upper East Rift Zone and caldera south of Halemaʻumaʻu.

It is not possible to say whether the increase in activity will lead to an intrusion or another eruption in the near future, or continue as seismic unrest.

Previous eruptions and intrusions beneath the upper East Rift Zone have occurred in the vicinity of Pauahi Crater and Hiʻiaka Crater to the southeast and around Luamanu and Keanakākoʻi Craters at the margin of the caldera.

Eruptions happened several times in the 1960s and 1970s in this region; the most recent was during a single day in November 1979 in and near Pauahi Crater.

There also is no indication that magma is moving toward the June 3 eruption site southwest of the caldera. However, changes in the character and location of unrest at Kīlauea can occur quickly, as can the potential for eruption.

The Hawaiian Volcano Observatory will continue to provide daily Kīlauea updates. 

Should volcanic activity change significantly, a Volcanic Activity Notice will be issued.