Recent Kīlauea Eruption Ends, Seismic Activity Monitored

Kīlauea volcano is not erupting. The eruption that began on Monday, June 3, southwest of Kaluapele (Kīlauea caldera) within Hawai'i Volcanoes National Park has ended. Incandescence from the fissure vents is no longer visible in nighttime webcam images. Volcanic gas emissions at the eruption site have decreased significantly and are approaching background levels. Earthquake counts in the summit region remain elevated, while tremor has dropped to background levels. Inflationary ground deformation of the summit continues. Although the eruption has ended, renewed pulses of seismicity and deformation could result in new eruptive episodes within the area or elsewhere within the summit region. Eruption Site Observations: No lava is erupting. Glow from fissure vents is no longer visible in webcam imagery. Volcanic gas emissions at the eruption site are approaching background levels (100 tonnes per day or less). Total SO2 emission rates for the summit and eruption site of approximately 400 t/d were measured on June 6. Seismic activity remains low at the eruption site. Summit and Upper Rift Zone Observations: Rates of seismicity beneath the summit, upper East Rift Zone, and upper Southwest Rift Zone were elevated over the past day. Over 60 earthquakes occurred over the past 24 hours. Earthquakes were mostly located beneath the south caldera region and upper East Rift Zone, at depths of 1.5-3 km (1–1.8 miles), with magnitudes under M2.5. Tremor has decreased to background levels across the summit region. Inflationary ground deformation of the summit continued over the past day. The Uēkahuna tiltmeter northwest of the summit recorded overall inflation of approximately 1.5 microradian over the past 24 hours, with little overall change since 6:00 p.m. HST last night. The Sand Hill tiltmeter southwest of the summit recorded approximately 6 microradians of inflation over the past 24 hours. Lower Rift Zone Observations: Rates of seismicity and ground deformation beneath the middle and lower East Rift Zone and lower Southwest Rift Zone are low. Eruptive activity and unrest have been restricted to the summit and upper rift zone regions. Measurements from continuous gas monitoring stations downwind of Puʻuʻōʻō in the middle East Rift Zone remain below detection limits for SO2, indicating that SO2 emissions from Puʻuʻōʻō are negligible. Eruption Summary: Emplacement of a magmatic dike began just after 12:00 p.m. HST on June 2, 2024, beneath the area of Kaluapele south of Halemaʻumaʻu. Seismicity continued to intensify beneath this area and HVO raised the alert levels from Advisory/Yellow to Watch/Orange as the dike shallowed. Around 8:00 p.m. on June 2 a strong deflation signal on the Sand Hill tiltmeter indicated that a significant mass of lava moved to another location despite a lack of seismicity. After the deflationary event, seismicity declined significantly, and it was no longer possible to track the underground location of the magma. Data from USGS webcams and Keck Observatory webcams determined that the eruption began at 12:30 a.m. June 3, and effusion at the vents remained active until approximately 9:00 a.m., though lava flows were moving sluggishly until about noon on June 3. Numerous large ground cracks formed in the vicinity of the eruption extending westward to within 540 yards (500 meters) of Maunaiki. Sulfur dioxide (SO2) emission rates of 12,000-15,000 t/d were measured on June 3, and 5,500 t/d on June 4. Two new webcams monitor the recent eruption site: https://www.usgs.gov/volcanoes/kilauea/s1cam-view-upper-southwest-rift-zone-kilauea-view-southwest and https://www.usgs.gov/observatories/hvo/s2cam-view-upper-southwest-rift-zone-kilauea-view-south Mapped eruptive fissures and lava flow extent on a GIS satellite image background. USGS Hawaii eruption map - preliminary (arcgis.com) A map showing the location of this eruption and past eruptions in this area is available here: June 6, 2024 — Kīlauea Southwest Rift Zone eruption | U.S. Geological Survey (usgs.gov) Analysis: The last eruption in this area occurred in December 1974. The 1974 eruption lasted 6 hours and erupted 13 million cubic yards (10 million cubic meters) of lava that covered about 3 square miles (7 square kilometers). In contrast, the June 3, 2024, eruption lasted 8.5 hours but only erupted about 1% of the volume and covered about one third of a square mile (one half of a square kilometer). Lava from the fissure system covered approximately 90 acres (350,000 square meters), a relatively small area. The pasty surface textures of the erupted lava and the small amount of lava erupted suggests that this lava could have been first emplaced during the January 31, 2024, intrusive event and cooled prior to being forced to the surface by the new dike. Although the eruption has ended, renewed pulses of seismicity and deformation could result in new eruptive episodes within the area or elsewhere in the summit region. Photo: (In addition to elevated volcanic gas emissions, other significant hazards also remain around the recent eruption site on the upper Southwest Rift Zone of Kīlauea. Minor to severe ground fractures and subsidence features that formed during the June 3 eruption may continue to widen and offset, may have unstable overhanging edges, and should be avoided. Most cracks that formed during the June 3 Kīlauea Southwest Rift Zone eruption are several inches (2 to 5 centimeters) wide with some extending to up to 6.5 feet (2 meters) wide. In this photo, a crack extends towards Pu‘ukoa‘e in the background. USGS photo by A.R. Nalesnik.) Via Hawaiian Volcano Observatory