Mammoth Mountain | U.S. Geological Survey
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Mammoth Mountain
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Mammoth Mountain
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Mammoth Mountain is a 3,369-m (11,053 ft) high lava-dome complex on the southwest topographic rim of Long Valley Caldera. It is considered to represent a magmatic system distinct from Long Valley Caldera and the Mono-Inyo Craters.
Quick Facts
Location:
California, Mono County
Latitude:
37.631° N
Longitude:
119.032° W
Elevation:
3,369 (m) 11,053 (f)
Volcano type:
lava domes
Composition:
trachydacite
Most recent eruption:
700 years ago (phreatic)
Nearby towns:
Mammoth Lakes
Threat Potential:
Moderate*
*based on the
National Volcano Early Warning System
Summary
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Sources/Usage: Public Domain.
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View of the Mammoth Mountain lava dome complex overlooking Horseshoe Lake.
Eruptions at Mammoth Mountain occurred from 100,000 to 50,000 years ago. Mammoth Mountain is surrounded by at least 35 mafic vents that are part of the same magmatic system and include Red Cones, two closely spaced basaltic cinder cones located southwest of Mammoth Mountain and southeast of Devils Postpile National Monument. The cones, whose name derives from colorful mantling scoria deposits, are unglaciated and were radiocarbon dated at about 8,000 years ago. Phreatic eruptions, distinct from those at South Inyo Craters, took place about 700 years ago from vents on the north side of Mammoth Mountain. Recent volcanic unrest, including seismicity, gas emission, and tree kill, is thought to be related to a dike intrusion beneath Mammoth Mountain in 1989. Both Long Valley Caldera and Mammoth Mountain have experienced episodes of heightened unrest over the last few decades (earthquakes, ground uplift, and/or volcanic gas emissions). As a result, the USGS manages a dense array of field sensors providing the real-time data needed to track unrest and assess hazards.
Keeping watch on Mammoth Mountain's volcanic breath
August 26, 2025
Keeping watch on Mammoth Mountain's volcanic breath
What's normal for a volcano? How CalVO scientists decide when to raise an alarm (or not)
December 4, 2024
What's normal for a volcano? How CalVO scientists decide when to raise an alarm (or not)
Unpacking CalVO's new seismic monitoring boxes
May 13, 2020
Unpacking CalVO's new seismic monitoring boxes
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February 25, 2019
California’s exposure to volcanic hazards
California’s exposure to volcanic hazards
The potential for damaging earthquakes, landslides, floods, tsunamis, and wildfires is widely recognized in California. The same cannot be said for volcanic eruptions, despite the fact that they occur in the state about as frequently as the largest earthquakes on the San Andreas Fault. At least ten eruptions have taken place in the past 1,000 years, and future volcanic eruptions are...
Authors
Margaret Mangan, Jessica Ball, Nathan Wood, Jamie L. Jones, Jeff Peters, Nina Abdollahian, Laura Dinitz, Sharon Blankenheim, Johanna Fenton, Cynthia Pridmore
By
Volcano Hazards Program
Volcano Science Center
California Volcano Observatory
Clear Lake Volcanic Field
Coso Volcanic Field
Lassen Volcanic Center
Long Valley Caldera
Mammoth Mountain
Medicine Lake
Mono Lake Volcanic Field
Mono-Inyo Craters
Mount Shasta
Salton Buttes
Soda Lakes
Ubehebe Craters
October 22, 2018
2018 update to the U.S. Geological Survey national volcanic threat assessment
2018 update to the U.S. Geological Survey national volcanic threat assessment
When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners...
Authors
John W. Ewert, Angela K. Diefenbach, David W. Ramsey
By
Volcano Hazards Program
Volcano Science Center
Agrigan
Ahyi Seamount
Alamagan
Anatahan
Asuncion
Belknap
Black Butte Crater Lava Field
Black Rock Desert Volcanic Field
Blue Lake Crater
Carrizozo Lava Flow
Cascade Range Weekly Update
Cinnamon Butte
Clear Lake Volcanic Field
Coso Volcanic Field
Crater Lake
Craters of the Moon Volcanic Field
Daikoku Seamount
Davis Lake Volcanic Field
Devils Garden Lava Field
Diamond Craters Volcanic Field
Dotsero Volcanic Center
East Diamante
Esmeralda Bank
Farallon de Pajaros
Fukujin Seamount
Glacier Peak
Guguan
Haleakalā
Hell's Half Acre Lava Field
Hualālai
Indian Heaven Volcanic Field
Jordan Craters Volcanic Field
Kama‘ehuakanaloa
Kasuga 2
Kīlauea
Lassen Volcanic Center
Long Valley Caldera
Mammoth Mountain
Markagunt Plateau Volcanic Field
Maug Islands
Mauna Kea
Mauna Loa
Medicine Lake
Mono Lake Volcanic Field
Mono-Inyo Craters
Mount Adams
Mount Bachelor
Mount Baker
Mount Hood
Mount Jefferson
Mount Rainier
Mount Shasta
Mount St. Helens
Newberry
Ofu-Olosega
Pagan
Red Hill-Quemado Volcanic Field
Ruby
Salton Buttes
San Francisco Volcanic Field
Sand Mountain Volcanic Field
Sarigan
Soda Lakes
South Sarigan Seamount
Supply Reef
Ta'u Island
Three Sisters
Tutuila Island
Ubehebe Craters
Uinkaret Volcanic Field
Valles Caldera
Wapi Lava Field
Weekly Update
West Crater Volcanic Field
Yellowstone
Zealandia Bank
Zuni-Bandera Volcanic Field
December 10, 2014
The California Volcano Observatory: Monitoring the state's restless volcanoes
The California Volcano Observatory: Monitoring the state's restless volcanoes
Volcanic eruptions happen in the State of California about as frequently as the largest earthquakes on the San Andreas Fault Zone. At least 10 eruptions have taken place in California in the past 1,000 years—most recently at Lassen Peak in Lassen Volcanic National Park (1914 to 1917) in the northern part of the State—and future volcanic eruptions are inevitable. The U.S. Geological...
Authors
Wendy K. Stovall, Mae Marcaida, Margaret T. Mangan
By
Natural Hazards Mission Area
Volcano Hazards Program
Volcano Science Center
Clear Lake Volcanic Field
Coso Volcanic Field
Lassen Volcanic Center
Long Valley Caldera
Mammoth Mountain
Mono Lake Volcanic Field
Mono-Inyo Craters
Mount Shasta
Salton Buttes
Soda Lakes
Ubehebe Craters
View All
November 3, 2023
Volcanic Gas Monitoring at Mammoth Mountain
USGS Volcano Hazards Program researchers evaluate changes in volcanic gas concentration at Mammoth Mountain.
By
California Volcano Observatory
Mammoth Mountain
Volcanic Gas Monitoring at Mammoth Mountain
November 3, 2023
Volcanic Gas Monitoring at Mammoth Mountain
USGS Volcano Hazards Program researchers evaluate changes in volcanic gas concentration at Mammoth Mountain.
November 3, 2023
Deformation monitoring at Mammoth Mountain
When magma moves into a volcanic system, and closer to the surface of the earth, the area surrounding the volcano may move upward and outward. This swelling is typically measured using the Global Positioning System (GPS). The GPS receivers near Mammoth Mountain are part of the 46 instruments that make up the Long Valley Caldera deformation monitoring network.
By
California Volcano Observatory
Mammoth Mountain
Deformation monitoring at Mammoth Mountain
November 3, 2023
Deformation monitoring at Mammoth Mountain
When magma moves into a volcanic system, and closer to the surface of the earth, the area surrounding the volcano may move upward and outward. This swelling is typically measured using the Global Positioning System (GPS). The GPS receivers near Mammoth Mountain are part of the 46 instruments that make up the Long Valley Caldera deformation monitoring network.
November 3, 2023
Seismic monitoring at Mammoth Mountain
The seismometers located near Mammoth Mountain are part of the greater Long Valley Caldera seismic network array. Data from group of 61 seismometers help to determine earthquake location, energy, waveform and evolution of movement with time.
By
California Volcano Observatory
Mammoth Mountain
Seismic monitoring at Mammoth Mountain
November 3, 2023
Seismic monitoring at Mammoth Mountain
The seismometers located near Mammoth Mountain are part of the greater Long Valley Caldera seismic network array. Data from group of 61 seismometers help to determine earthquake location, energy, waveform and evolution of movement with time.
View All
Quick Facts
Location:
California, Mono County
Latitude:
37.631° N
Longitude:
119.032° W
Elevation:
3,369 (m) 11,053 (f)
Volcano type:
lava domes
Composition:
trachydacite
Most recent eruption:
700 years ago (phreatic)
Nearby towns:
Mammoth Lakes
Threat Potential:
Moderate*
*based on the
National Volcano Early Warning System
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