Recent Volcano Updates from the U.S. Geological Survey Volcano Hazards Program https://volcanoes.usgs.gov U.S. Geological Survey Volcano Hazards Program Sun, 20 Sep 2026 19:15:05 +0000 Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. No significant earthquake activity was detected and clouds obscured satellite and webcam images over the past day.The current eruption began in July 2021. Since then, lava flows have filled most of the summit crater and advanced into valleys below. There have been no explosions at Great Sitkin Volcano since an event in May 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data, webcams, and regional infrasound and lightning networks. https://www.avo.alaska.edu/activity/GreatSitkin.php https://www.avo.alaska.edu/activity/GreatSitkin.php avo 52.0765 -176.1109 WATCH ORANGE Unrest continues at Shishaldin Volcano, with minor seismic activity detected. High winds obscured infrasound signals while clouds obscured other satellite and webcam images. Local seismic and infrasound sensors, web cameras, and a geodetic network are used to monitor Shishaldin Volcano. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lightning data, and satellite images to detect eruptions. https://avo.alaska.edu/activity/Shishaldin.php https://avo.alaska.edu/activity/Shishaldin.php avo 54.7554 -163.9711 ADVISORY YELLOW Volcano Observatory Notice for Aviation (VONA) and associated Volcano Activity Notices (VAN) are now required to be repeated every day for volcanoes at RED, every week for volcanoes at ORANGE, and every two weeks for volcanoes at YELLOW.The Halemaʻumaʻu eruption of Kīlauea volcano is currently paused, current forecast for episode XX fountaining onset is MONTH XX-XX. Episode XX fountaining ended at XX a.m./ p.m. HST on DAY MONTH XX, YEAR.All eruptive vents and lava flows are confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park. Tephra fall from volcanic ash clouds is ... https://www.usgs.gov/volcanoes/kilauea https://www.usgs.gov/volcanoes/kilauea hvo 19.421 -155.287 WATCH ORANGE Activity Update: All volcanoes in the Cascade Range of Washington and Oregon are at normal background activity levels. These include Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams in Washington State and Mount Hood, Mount Jefferson, Three Sisters, Newberry, and Crater Lake in Oregon.Past Week Observations: During the past week, small earthquakes were detected at Mount Rainier and Mount St. Helens. All monitoring data remain consistent with background activity levels throughout the Cascade Range. This week, field crews conducted helicopter-supported maintenance of ... https://volcanoes.usgs.gov/observatories/cvo https://volcanoes.usgs.gov/observatories/cvo cvo 45.61 -122.5 NORMAL GREEN No notable activity was detected in distal geophysical monitoring data or satellite images over the past week. Eruptive activity at Ahyi seamount may present a hazard to mariners in the water above and near the volcano. The summit has shallowed over the course of previous eruptions to 180 feet (55 m) below sea level, but the lack of local real-time data means we are unable to forecast or warn of impending eruptions. We will continue to monitor satellite and distal hydroacoustic data for additional evidence for, or escalation of, volcanic activity. https://www.usgs.gov/volcanoes/ahyi-seamount https://www.usgs.gov/volcanoes/ahyi-seamount nmi 20.437 145.03 ADVISORY YELLOW Seismicity at Mount Kupreanof was relatively quiet over the past week, with local earthquake activity rarely observed. Steaming continues, but sulfur dioxide emissions have become weak and rare – the last sulfur dioxide detection was on September 6. Because of the decline in unrest, the Alaska Volcano Observatory lowered the Aviation Color Code and the Volcano Alert Level at Mount Kupreanof to UNASSIGNED on September 8. A new temporary monitoring station was installed near Mount Kupreanof in July 2026 and is intermittently providing seismic data, infrasound data, gas measurements, and web ... https://avo.alaska.edu/volcanoes/volcinfo.php?volcname=Kupreanof https://avo.alaska.edu/volcanoes/volcinfo.php?volcname=Kupreanof avo 56.0126 -159.7912 UNASSIGNED UNASSIGNED No significant activity was detected at Ofu-Olosega volcano during the past month. The USGS National Earthquake Information Center reported no earthquakes of magnitude 2.5 or greater in the vicinity of the volcano. https://www.usgs.gov/volcanoes/ofu-olosega https://www.usgs.gov/volcanoes/ofu-olosega hvo -14.175 -169.618 NORMAL GREEN No significant activity was detected at Taʻū volcano during the past month. The USGS National Earthquake Information Center reported no earthquakes of magnitude 2.5 or greater in the vicinity of the volcano. A Global Positioning System (GPS) instrument on Taʻū Island recorded no significant deformation.The FAGA broadband seismometer located on eastern Taʻū Island is currently out of service. The TAU broadband seismometer on western Taʻū Island remains operational.The TAU1 GPS station has experienced intermittent data outages and HVO is evaluating the quality of transmitted data. https://www.usgs.gov/volcanoes/ta-u-island https://www.usgs.gov/volcanoes/ta-u-island hvo -14.23 -169.454 NORMAL GREEN No significant activity was detected at Tutuila volcano during the past month. The USGS National Earthquake Information Center reported no earthquakes of magnitude 2.5 or greater in the vicinity of the volcano. https://www.usgs.gov/volcanoes/tutuila-island https://www.usgs.gov/volcanoes/tutuila-island hvo -14.295 -170.7 NORMAL GREEN No significant activity was detected at Haleakalā volcano during the past month. The continuously recording Global Positioning System (GPS) instrument on Haleakalā lost connection on July 13th. No significant deformation was recorded leading up to the outage. The station is owned and operated by researchers at the Pacific GPS Facility (PGF), as part of the Hawaii Institute of Geophysics and Planetology (HIGP), who will service the station within the next few months to bring it back online. https://www.usgs.gov/volcanoes/haleakal%C4%81 https://www.usgs.gov/volcanoes/haleakal%C4%81 hvo 20.708 -156.25 NORMAL GREEN No significant activity was detected at Hualālai volcano during the past month. Seismic activity remained low and was representative of background activity levels at the volcano. The continuously recording Global Positioning System (GPS) instrument on Hualālai has been offline since March 15, 2026; HVO field engineers will service the station within the next few months to bring it back online. https://www.usgs.gov/volcanoes/hual%C4%81lai https://www.usgs.gov/volcanoes/hual%C4%81lai hvo 19.692 -155.87 NORMAL GREEN No significant activity was detected at Kamaʻehuakanaloa volcano (formerly Lōʻihi Seamount) during the past month. Seismic activity remained low and was representative of background activity levels at the volcano. https://www.usgs.gov/volcanoes/kama%E2%80%98ehuakanaloa https://www.usgs.gov/volcanoes/kama%E2%80%98ehuakanaloa hvo 18.92 -155.27 UNASSIGNED UNASSIGNED No significant activity was detected at Mauna Kea volcano during the past month. Seismic activity remained low and was representative of background activity levels at the volcano. The continuously recording Global Positioning System (GPS) instrument on Mauna Kea, operated by NASA's Jet Propulsion Laboratory, recorded no significant deformation in the past month. https://www.usgs.gov/volcanoes/mauna-kea https://www.usgs.gov/volcanoes/mauna-kea hvo 19.82 -155.47 NORMAL GREEN Mauna Loa had an increase in seismic activity compared to the previous month; a total of 87 earthquakes were detected in Mauna Loa's summit region during the August reporting period, after 57 in July. Most earthquakes occurred deep beneath the upper Southwest Rift Zone or broadly scattered around the upper flanks. Very few earthquakes occurred directly beneath Mokuʻāweoweo.Data from Global Positioning System (GPS) instruments on Mauna Loa showed slight inflation across the summit region in the past month. Most GPS stations at the summit recorded small upward vertical motions while shifting ... https://www.usgs.gov/volcanoes/mauna-loa https://www.usgs.gov/volcanoes/mauna-loa hvo 19.475 -155.608 NORMAL GREEN Yellowstone Caldera activity remains at background levels, with 61 located earthquakes in August (largest = M2.0). Deformation measurements indicate no significant uplift of the north caldera rim since January 2026 and only minor uplift of the caldera since the beginning of the year. Recent Work and NewsAugust field work included studies of hydrothermal explosion craters and glacial geology, as well as continued upgrades to the Yellowstone Seismic Network. In September, YVO hopes to bring a new seismic and infrasound station fully online in Upper Geyser Basin. The station is designed to ... https://www.usgs.gov/volcanoes/yellowstone https://www.usgs.gov/volcanoes/yellowstone yvo 44.43 -110.67 NORMAL GREEN Strong northwesterly winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes have picked up loose volcanic ash erupted during the 1912 Novarupta-Katmai eruption and are carrying it to the southeast. The National Weather Service has issued a SIGMET for this low-level event and suggests that the maximum cloud height is 6,000 ft (1.83km) above sea level.This phenomenon is not the result of recent volcanic activity and occurs during times of high winds and dry snow-free conditions in the Katmai area and other young volcanic areas of Alaska. No eruption is in progress. All of the ... https://avo.alaska.edu/volcanoes/volcinfo.php?volcname=Katmai https://avo.alaska.edu/volcanoes/volcinfo.php?volcname=Katmai avo 58.279 -154.9533 NORMAL GREEN A large rock and ice avalanche on the eastern flank of Iliamna Volcano was detected by seismic and infrasound sensors at 07:57 AKDT (15:57 UTC) on Saturday, August 8. The source area of the avalanche was also visible in web camera data. Large avalanches are common at this volcano, and the event does not indicate volcanic unrest. Avalanches of similar size have been previously observed in 2016, 2019 and 2023. https://avo.alaska.edu/volcanoes/volcinfo.php?volcname=Iliamna https://avo.alaska.edu/volcanoes/volcinfo.php?volcname=Iliamna avo 60.0319 -153.0918 NORMAL GREEN A small explosion from Korovin Volcano within the Atka Volcanic complex was detected in seismic and infrasound data on July 16, 2026. Since then, unrest has declined. As a result, the Aviation Color Code and Alert Level are being lowered to GREEN/NORMAL. https://avo.alaska.edu/volcanoes/volcinfo.php?volcname=Atka https://avo.alaska.edu/volcanoes/volcinfo.php?volcname=Atka avo 52.3309 -174.139 NORMAL GREEN