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Volcano Hazards Program

Find U.S. Volcano

There are about 170 potentially active volcanoes in the U.S. The mission of the USGS Volcano Hazards Program is to enhance public safety and minimize social and economic disruption from volcanic unrest and eruption through our National Volcano Early Warning System. We deliver forecasts, warnings, and information about volcano hazards based on a scientific understanding of volcanic behavior.

News

Photo & Video Chronology — March 20, 2025 — Kīlauea summit eruption episode 14

Photo & Video Chronology — March 20, 2025 — Kīlauea summit eruption episode 14

Volcano Watch — A collapse at Mauna Loa’s summit in 1868, like Kīlauea’s in 2018?

Volcano Watch — A collapse at Mauna Loa’s summit in 1868, like Kīlauea’s in 2018?

Photo & Video Chronology — March 19, 2025 — Kīlauea summit eruption

Photo & Video Chronology — March 19, 2025 — Kīlauea summit eruption

Publications

Volcanic gases reflect magma stalling and launching depths

Many open-vent arc volcanoes display two modes in their continuous gas emissions, one with a characteristic CO2/ ST ratio typical of periods of quiescent degassing and another punctuated by high CO2/ ST gas emitted in the weeks before eruption, a recently recognized eruption precursor. In this study we explore the origin of the two modes of degassing revealed by time-series gas data at...
Authors
Shuo Ding, Terry Plank, J. Maarten de Moor, Yves Moussallam, Maryjo Brounce, Peter J. Kelly

Fast or slow: An evaluation of Ti-in-quartz diffusion coefficients through comparisons of quartz and plagioclase diffusion times

Diffusion geochronometry using Ti-in-quartz has become a valuable method in understanding the evolution of silicic magmas. However, four different options for Ti diffusivity (DTi) currently exist, spanning three orders of magnitude, resulting in substantially different estimated times and interpretations. We present Ti-in-quartz diffusion times for the Cerro Galán Ignimbrite using the...
Authors
Sophia Wang, Guilherme Gualda, Jordan Edward Lubbers, Adam Kent

Monitoring lava lake fluctuations and crater refilling with continuous laser rangefinders

The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) has developed a new method to continuously monitor lava lake elevations. Since 2018, HVO has stationed a laser rangefinder on Kīlauea’s caldera rim. The instrument automatically measures lava lake elevation each second, with centimeter accuracy. A stream of elevation data flows to HVO’s database and public website...
Authors
Edward F. Younger, William Tollett, Matthew R. Patrick
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