Kīlauea volcano rattled by nearly 1,000 earthquakes in three days

Nearly 1,000 earthquakes over the past three days have rattled Kīlauea volcano on the Big Island.

According to the Hawaiian Volcano Observatory, 250 of those earthquakes exceeded magnitude 2. The largest event was a magnitude 3.6. All have remained between 0.6 and 1.8 miles beneath the surface.

As of 4:30 p.m. on July 24, magma continues to move into the vertical, sheet-like body, or dike, beneath the upper East Rift Zone near Kīlauea’s Pauahi Crater.

“An eruption is not currently imminent, but conditions could change rapidly,” the Hawaiian Volcano Observatory stated Wednesday evening.

Unrest below Kīlauea has been restricted to the upper East Rift Zone; no unusual activity has been noted along the volcano’s middle and lower East Rift Zones or the Southwest Rift Zone.

The rapid onset and concentrated intensity of the July 22–24 earthquake swarm, coupled with abrupt changes in upper East Rift Zone ground deformation patterns, show that an intrusion of magma is occurring in the area of Pauahi Crater, the Hawaiian Volcano Observatory said.

“It is not possible to forecast an exact outcome of this activity. Future eruptions are possible with little warning along the upper portions of Kīlauea’s East Rift Zone,” Hawaiian Volcano Observatory said. “Recent Kīlauea eruptions have occurred with as little as one hour or less of advanced warning in the form of accelerated rates of ground deformation and earthquakes.”

The Hawaiian Volcano Observatory has issued the following possible scenarios that could occur in the coming days or weeks:

• The intrusion grows: Magma continues to accumulate below the surface near Pauahi Crater on Kīlauea’s upper East Rift Zone as an intrusion.
  
• An upper East Rift Zone eruption occurs: Magma continues to accumulate below the surface near Pauahi Crater on Kīlauea’s upper East Rift Zone, resulting in an eventual upper East Rift Zone eruption.
  
• The intrusion moves east: Magma continues to accumulate below the surface near Pauahi Crater on Kīlauea’s upper East Rift Zone, eventually establishing a path to the east, in Kīlauea’s middle East Rift Zone, as occurred during the Father’s Day intrusion in 2007.

The Hawaiian Volcano Observatory briefly raised the alert level/aviation color code for Kīlauea from advisory/yellow to watch/orange during the most intense recent pulse of upper East Rift Zone unrest on July 23.

Hawai‘i Volcanoes National Park has implemented temporary closures as a result of the intrusion: Click here for more information.

The Hawaiian Volcano Observatory deployed its KOcam to Maunaulu to monitor the upper East Rift Zone in May. It’s available here.

The observatory’s K2cam, located at Uēkahuna bluff, has been re-aimed and zoomed to view the upper East Rift Zone: See here.