Activity Summary:  Kīlauea volcano is not erupting. Activity has decreased to background levels beneath the upper East Rift Zone the caldera south of Halemaʻumaʻu.  The period of heightened unrest has ended.

Summit and upper East Rift Zone Observations: Earthquake counts in the upper East Rift Zone have decreased to background levels with approximately 18 earthquakes the past 24 hours compared to over 350 per day at the peak of the unrest. Earthquake locations remain focused primarily from the southeast side of Kaluapele (Kīlauea caldera) beneath Keanakākoʻi crater extending to the intersection with Hilina Pali Road. Earthquake depths remain unchanged, averaging 2-3 km (1.2-1.9 miles) beneath the surface.  Most of the earthquakes were less than M1 with a M2.3 as the maximum in the past 24 hours. There have been no earthquakes in the caldera south of Halemaʻumaʻu over this same period.  More than 2000 earthquakes were recorded during the heightened unrest from April 27 to May 03.  More than 1800 of these earthquakes occurred beneath the upper East Rift Zone during this period.  Another 200 earthquakes were recorded beneath Kaluapele south of Halemaʻumaʻu in the first two days of the event.

Ground deformation has effectively ceased beneath Halemaʻumaʻu and the south side of Kalaupele and Keanakākoʻi crater with a little over 1 microradian inflation on both tiltmeters in the last 24 hours.. The Uēkahuna tiltmeter began recording mild inflation at approximately 4:30 AM today as part of a local deflation-inflation (DI) event beneath Halemaʻumaʻu. This is also reflected in the Sandhill tiltmeter, which has otherwise recorded little change in the past 48 hours.

Sulfur dioxide (SO₂) gas emission rates remain low. An SO₂ emission rate of approximately 62 tonnes per day was recorded on May 2nd. 

Rift Zone Observations: All seismic activity on the East Rift Zone is confined to the upper East Rift Zone, with no significant earthquakes occurring past the Pauahi Crater. At this time, seismicity south of Kaluapele and in Kīlauea's Southwest Rift Zone remains low overall. Measurements from continuous gas monitoring stations downwind of Puʻuʻōʻō in the middle East Rift Zone—the site of 1983–2018 eruptive activity—continue to be below detection limits for SO₂, indicating that SO₂ emissions from Puʻuʻōʻō are negligible. 

Analysis: The decrease in both seismicity and ground deformation to background levels indicates that the pulse of unrest that began on April 27th by noon on May 03.. The unrest was driven by magma input to the main magma chamber, which lies beneath the area southeast of Kaluapele and south of Keanakākaoʻi crater. The significant drop in inflation rate, especially at the Sand Hill tiltmeter, suggests that the magma supply is greatly reduced and no longer pressurizing the magma chamber and producing seismicity. Magma input into the system has changed during the past year from relatively constant to occurring in pulses. Resumption of magma input could occur at anytime and build to another period of unrest, most likely in the upper East Rift Zone, within Kaluapele, or south of Kaluapele where the intrusion occurred in late January-early February.

Information Statement Issued May 2, 2024: An information statement summarizing the event since April 27, including interpretation and possible outcomes, can be found here:  Kīlauea Information Statement: summit region heightened unrest continues; no eruptive activity. | U.S. Geological Survey (usgs.gov)

Updates: The USGS Hawaiian Volcano Observatory (HVO) will provide daily updates while at a heightened state of unrest. 

HVO continues to closely monitor Kīlauea for signs of increasing activity. Should volcanic activity change significantly, a Volcanic Activity Notice will be issued.   

Hazards are still present on Kīlauea and are described below. Residents and visitors should stay informed and follow County of Hawai‘i and Hawaiʻi Volcanoes National Park guidelines.