Activity Summary:  Kīlauea volcano is not erupting. The significant increase in seismicity beneath the upper East Rift Zone and caldera south of Halemaʻumaʻu that began on April 27 is continuing. Updates are being provided daily while the heightened state of unrest continues. 

Summit and upper East Rift Zone Observations:  Earthquake activity increased sharply just after midnight on April 27 beneath the upper East Rift Zone and beneath Kīlauea caldera south of Halemaʻumaʻu. Earthquake locations beneath the upper Easth Rift Zone continue to be focused primarily between Puhimau Crater and Hilina Pali Road, with slight expansion northwest toward Keanakākoʻi Crater and southeast toward Pauahi Crater over the past 24 hours. Earthquakes are occurring at depths of 1.5-2.5 km (1-1.5 miles) beneath the surface. There were over 360 earthquakes in the past 24 hours, about the same number as the previous 24 hours, located mostly beneath the upper East Rift Zone with fewer in the caldera south of Halemaʻumaʻu. Unlike the previous 24 hours, no earthquakes greater than magnitude-3 were observed in the past 24 hours. Most earthquakes were less than magnitude-2 punctuated by occasional larger earthquakes with magnitudes between 2 and 3. Activity is ongoing at a rate of about 15 earthquakes per hour.

Accelerated rates of ground deformation continue with ongoing overall inflation of the summit and uplift south of the caldera. Tiltmeters near Uēkahuna and Sand Hill showed increased rates of inflation and uplift yesterday until about 6:00 PM when rates decreased slightly with the onset of a deflation-inflation (DI) event. 

Sulfur dioxide (SO2) gas emission rates remain low. An SO2 emission rate of approximately 52 tonnes per day was recorded on April 23. 

Rift Zone Observations:  All seismic activity on the East Rift Zone is confined to the upper East Rift Zone, with no significant earthquakes or deformation occurring past the Mauna Ulu region. Seismicity 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 Puʻuʻōʻō are negligible. 

Analysis:  At this time, it is not possible to say with certainty if this increase in activity will lead to an eruption in the near future – or simply remain confined below ground. However, the gradual strengthening of seismic swarms suggests that an eruption in Kīlauea’s summit region or beneath the upper East Rift Zone, within Hawai‘i Volcanoes National Park, is one potential outcome. 

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.