USGS Volcanoes🌋

FWIW: official USGS volcano information will always come from accounts that have the handles @USGSVolcanoes, @alaska_avo, & @USGS and are linked from our web pages. Visit usgs.gov/programs/VHP/connec… for info.

🌋 What happens when a volcano erupts where no one can see it? Ruby seamount, near the Northern Mariana Islands, erupted explosively in 2023, then seemed to go quiet. But new surveys in 2026 revealed it had been quietly growing a new lava dome deep beneath the ocean. The hidden lives of submarine volcanoes are full of surprises. 🌊🔍 Read more: usgs.gov/observatories/hvo/n… 📷: Lava erupted from Ruby seamount. #VolcanoWatch #SubmarineVolcano #OceanExploration

How do USGS scientists stay safe when they're working in remote places? Recent rescues on Mount Shasta remind us that even if California's volcanoes are close to cities or towns, their slopes are wild and hard-to-reach. When USGS scientists visit volcanoes, they're required to be certified in Wilderness First Aid.  The certification is not only for wilderness, but also for anyplace that might be more than an hour from professional medical assistance. This could be anywhere from a few miles into a popular hiking route, or in a car along major highways. In the classroom, USGS employees learn techniques to treat and stabilize injuries, but also get to practice on each other! Another part of field safety is being properly supplied in case of an emergency. First Aid kits are an important first step, but planning is also important for any field excursion. Consider the environment being visited, how many people are in the group, what the weather will be, and how long the trip lasts. At volcanoes, this also means thinking about rockfalls, toxic gases, unstable ground, extreme temperatures, abrasive dust, and rugged terrain! Having safety plans and carrying the right equipment are must-dos, whether it's a satellite beacon and a climber's rack, or a map and compass. (If you're wondering, the USGS has free maps at the National Map's Topobuilder!)   Whether it's a short hike on a familiar trail or scaling a 14,000-foot volcano, safety comes down to preparation. Are you prepared for your next field foray? California Volcano Observatory Weekly Update for October 26, 2026: All volcanoes in California were at normal background levels of activity for the last week. Earthquakes >M1 were observed at the Coso Volcanic Field. 📷1: USGS scientists on Mount Shasta for gas sampling. Credit: Nick Meyers, USFS 📷2: An important part of Wilderness First Aid training is scenario practice, where trainees assess victims of unknown injuries. Credit: Outerlands Medics and Rescue 📷2: USGS scientists practice CPR training, which is useful in many situations - not just fieldwork! Credit: Outerlands Medics and Rescue

Recent studies are changing the way geologists think about the Lava Creek Tuff—the deposit that was created during the formation of Yellowstone Caldera 631,000 years ago. Today's Yellowstone Caldera Chronicles is a tuff read! Literally! ow.ly/TtS850ZYYpM 📷: Tuff Cliff, located north of Madison Junction in Yellowstone National Park, is one of the best-known exposures of the Lava Creek Tuff and has long been cited as a classic example of member A of that deposit. USGS photo by Mike Poland, September 24, 2026.

USGS Cascades Volcano Observatory scientists performing a routine helicopter observation flight at Mount Hood noticed that a seasonal meltwater pond at the base of the Coalman Glacier was significantly larger than in previous years. The pond lies in a basin bounded by Crater Rock, cliffs extending down from the summit, and Devil’s Kitchen, an earthen berm composed of hydrothermally altered rock and glacial moraine material. Devil’s Kitchen is a long-lived feature and appears stable based on current observations. The pond’s water volume is unknown but is estimated to be on the order of ~50,000 cubic meters, roughly equivalent to 20 Olympic-sized swimming pools. A water sample collected last week had a provisional measured pH of 4, which is similar to the pH of black coffee, indicating mildly acidic conditions. If all the water were released suddenly, it could generate a debris flow down the White River with the potential to reach the Highway 35 bridge. Topography would prevent the flow from traveling down the Sandy River or toward Timberline and Government Camp. Based on current estimates of the pond’s water volume, impacts to populated areas are not expected. USGS Cascades Volcano Observatory scientists are working with the U.S. Forest Service, the National Weather Service, Portland Mountain Rescue, and other agencies to make additional measurements and assess the stability of the meltwater pond. CVO will issue further updates as conditions warrant. The Cascades Volcano Observatory update for Friday, October 23, 2026: All volcanoes in the Cascade Range of Oregon and Washington were at normal background levels. Over the past week, there were small earthquakes detected at Mount St. Helens. Field crews conducted a gravity survey at Mount Hood, installed sensors at Spirit Lake near Mount St. Helens, and made improvements to monitoring stations at Mount Adams. Analysis of routine gas flight measurements at Mount Adams, Mount St. Helens, and Mount Hood indicate normal background levels of degassing. 📷 1: View of Mount Hood from the parking lot at Timberline looking north. From this vantage point, you can see the location of the melt pond and the White River drainage. Credit: H. Weiss-Racine 📷 2: The melt pond at Coalman Glacier as viewed from the USGS helicopter observation flight on October 6th, 2026. Credit: USGS

The caldera intrusion from September 30-October 1 happened amidst the ongoing episodic lava fountaining eruption at Kīlauea summit. Intrusions and eruptions often go hand-in-hand at Kīlauea. Since 2018, the volcano has experienced multiple summit and rift zone intrusions, followed by several eruptions. Read a summary here: usgs.gov/observatories/hvo/n… 📷 : Kīlauea lava fountaining episode 55 on October 17, 2026. #VolcanoWatch #Kilauea #Intrusion

Is Giant Geyser back??? ▶️ Giant Geyser is the second tallest geyser in Yellowstone National Park (behind only Steamboat Geyser) ▶️ Located not far from Old Faithful in Upper Geyser Basin ▶️ It can go many years between eruptions but then enter a period of frequent eruptions ▶️ The boiling water and steam plume can go up to about 200 feet (60 meters) above it's cone ▶️ Was very active in 2018-2019, but there were only single, isolated eruptions in 2023 and 2025 Giant Geyser sprang to life in summer 2026, with an eruption on June 26, and then settled into a pattern of having eruptions every 1-2 weeks during August, September, and October (most recently on October 13). Hopefully the geyser continues to put on a show throughout the coming winter and into next summer! @YellowstoneNPS

🧐🪨🌋 Have you been curious about the chemistry of Kīlauea’s summit lava fountains? 

If so, you might be interested in a new open-access publication led by USGS Hawaiian Volcano Observatory authors: 

Petrologic and geochemical characterization of the first year of the 2024–ongoing episodic Halema‘uma‘u eruption of Kīlauea (Episodes 1–39): sciencedirect.com/science/ar… 
📷: Photo shows Kīlauea eruption lava sampling. 
#Geochemistry #Kilauea #Science

It's not as pointy as Shasta or as explosive as Long Valley, but Medicine Lake is one of the most geologically diverse volcanoes in California! While it keeps a (visually) low profile, Medicine Lake volcano covers around 2,200 square km (850 square miles) of northern California. Though shield-shaped, it's actually not a shield volcano like Hawai'i's Kilauea—eruptions there range in composition from massive basaltic flows to rhyolite domes and dacite tuffs. Its summit caldera formed not from a massive explosion, but from subsidence after repeated lava flow eruptions, which also built its rim higher! It's also a place of fire and ice: It's been covered by glaciers multiple times in its half-million-year history, but its lava flows have hundreds of lava tubes which carried molten rock as far as 30 kilometers (20+ miles) from erupting vents. Not to mention that some of those lava tubes now hold ice caves! 📷1: Looking out from Glass Mountain to the west, Medicine Lake and the Medicine Lake Highlands frame Mount Shasta in the distance. 📷2: The entrance to Skull Cave, a huge lava tube about 19 km (12 miles) north of the Medicine Lake caldera. 📷3: Glacier polish and scratches on andesite lavas of the north rim of the Medicine Lake caldera. Credit: J. Donnelly-Nolan, USGS California Volcano Observatory Weekly Update for October 19, 2026: All volcanoes in California were at normal background levels of activity for the last week. Earthquakes >M1 were observed at the Clear Lake Volcanic Field, Mono-Inyo Craters, Coso Volcanic Field, and Salton Buttes.

There are lots of earthquakes in the Yellowstone region. How do scientists know if they are volcanic events driven by magma, or tectonic events caused by fault motion? Today's Yellowstone Caldera Chronicles shakes the answers loose. 🔗 ow.ly/G3Py50ZY5i5 📷1: Fault scarp in western Montana that formed as a result of the 1959 M7.3 Hebgen lake earthquake. USGS photo by J. R. Stacy. 📷2: Damage to the Mammoth-Norris highway, just south of Mammoth Hot Springs, caused by the June 30, 1975, magnitude-6 earthquake. Haynes Inc. photo for the Deseret News. 📷3: Gibbon River in Gibbon Meadows immediately following the June 30, 1975, magnitude-6 Yellowstone National Park earthquake. The muddy color is due to increased sediment load. NPS photo by Rick Hutchinson.

Kilauea Message 2026-10-17 09:13:41 HST. Episode 55 fountaining ended abruptly at 9:03 a.m. HST after just under 6 hours of eruption.

Kilauea Message 2026-10-17 07:47:26 HST. The north vent fountain has dropped to about 500 feet (150 m) high, about the same as the maximum fountain height for episodes 51-54. Top of the plume cloud has dropped under 13,000 ft (4,000 m) above sea level.

Kīlauea Eruption Update — Episode 55 of lava fountaining!    After nearly two months since episode 54 of lava fountaining (Aug. 25, 2026), episode 55 of Kīlauea summit lava fountaining began at 3:19 a.m. HST this morning, October 17, and is ongoing. 

This is the 55th lava fountaining episode in the Kīlauea summit caldera eruption in Hawai‘i Volcanoes National Park that began on December 23, 2024. It occurs following weeks of intermittent spatter, low-dome fountains, and lava flows from the eruptive vent complex. The lava fountain from the north vent reached an estimated 700 feet high above the vent around 5 a.m. Hawaii Standard Time.

The eruptive plume is reaching an estimated 25,000 feet above sea level. According to the National Weather Service, winds are blowing from the north-northeast direction, which suggests that volcanic gas emissions and volcanic material may be distributed to the south-southwest.  Fountaining episodes typically last 12 hours or less, but ash can remain in the air for longer depending on wind and weather conditions. 

Please stay aware of hazards and rely on official updates from USGS, National Weather Service, and Hawai’i Volcanoes National Park. 

🎥 Video of episode 55 on October 17, 2026. 

#Kilauea #Eruption #Lava

Kilauea Message 2026-10-17 06:02:51 HST. The north vent fountain has dropped to about 650 feet (200 m) high and the plume cloud is down to 17,000 feet asl. Lava flows are now covering about 30-40% of the floor of Halema'uma'u crater.

Kilauea Message 2026-10-17 05:11:55 HST. The north fountain is now just over 700 feet (220 m) with a plume cloud rising to about 25,000 feet (7500 m) a.s.l. Winds below 20,000 feet a.s.l. are from the northeast and most tephra is expected to be within the closed area of HVNP.

Kilauea Message 2026-10-17 04:21:15 HST. The north vent fountain has grown to about 250 feet (80 m) high and is at least as wide. The fountain is feeding a broad sheet of lava into Halema'uma'u crater. Wind is from the northeast and tephra is within the closed area of HVNP.

Kilauea Message 2026-10-17 03:40:12 HST. Episode 55 fountaining from the north vent began at 3:19 am HST October 17 after almost 24 hours of continuous overflows. There were 359 precursory overflows since the episode 54 fountains ended.

What is in the air near Mount St. Helens? It's volcanic ash from 1980! Volcanic ash resuspension at Mount St. Helens occurs when wind picks up loose ash and fine volcanic sediment deposited by past eruptions, carrying it back into the atmosphere. At Mount St. Helens, ash resuspension can occur when strong winds disturb exposed volcanic deposits, particularly in unvegetated areas of the crater, Pumice Plain, and surrounding landscape. Unlike a new eruption, this process does not involve fresh magma or newly erupted material. The Cascades Volcano Observatory update for Friday, October 16, 2026: All volcanoes in the Cascade Range of Oregon and Washington were at normal background levels. During the past week, small earthquakes were detected at Mount Hood, Mount Rainier, and Mount St. Helens. This week, field crews performed maintenance on monitoring stations at Three Sisters and Mount Rainier. On Thursday 15 Oct 2026, strong southeasterly winds resuspended volcanic ash in the vicinity of Mount St. Helens. The National Weather Service estimated that that the resulting ash cloud reached a maximum altitude of 12,000 ft (3,658 m) 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 Mount St. Helens region. 📷 View of the resuspended ash from the Mount St. Helens Coldwater Science and Learning Center on October 15, 2026. It appears as a large tan colored cloud that blocks the view of the mountain. Photo: T. Schenk, USFS

Six new eruptive vents opened along the western wall of Halemaʻumaʻu at the summit of Kīlauea on Sept. 14-16, 2026. 🌋 Data from tiltmeters, GPS, satellite radar, and lava chemistry indicate the vents were fed by the same shallow magma chamber that supplies Kīlauea's recent lava-fountaining episodes. Surprisingly, the vents opened with little seismicity or surface deformation, suggesting highly pressurized magma found an existing or easily created pathway to the surface. With continued pressurization beneath Kīlauea, additional changes remain possible both above and below ground. More information: usgs.gov/observatories/hvo/n… 🗺️/📷: Map and photos show ground deformation around the summit of Kīlauea from September 11-17, 2026, and plot shows erupted lava geochemistry. #Kilauea #VolcanoWatch #Geochemistry