Mammoth Mountain

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 37.631°N
  • 119.032°W

  • 3369 m
    11050 ft

  • 323150
  • Latitude
  • Longitude

  • Summit

  • Volcano

There are no activity reports for Mammoth Mountain.

 Available Weekly Reports

There are no Weekly Reports available for Mammoth Mountain.

Summary of eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1260 ± 40 years Unknown Confirmed   Radiocarbon (corrected) North flank of Mammoth Mountain
6960 BCE ± 500 years Unknown Confirmed 2 Radiocarbon (uncorrected) SSW of Mammoth Mtn (Red Cones)

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Browne B, Bursik M, Deming J, Louros M, Martos A, Stine S, 2010. Eruption chronology and petrologic reconstruction of the ca. 8500 yr B.P. eruption of Red Cones, southern Inyo chain, California. Geol Soc Amer Bull, 122: 1401-1422.

Bursik M, 2002-. Long Valley tephra database.

Hildreth W, 2004. Volcanological perspectives on Long Valley, Mammoth Mountain, and Mono Craters: several contiguous but discrete systems. J Volc Geotherm Res, 136: 169-198.

Hill D P, Prejean S, 2005. Magmatic unrest beneath Mammoth Mountain, California. J Volc Geotherm Res, 146: 257-283.

Huber N K, Eckhardt W W, 1985. Devils Postpile story. Sequoia Nat Hist Assoc, 30 p.

Huber N K, Rinehart C D, 1967. Cenozoic volcanic rocks of the Devils Postpile quadrangle, eastern Sierra Nevada California. U S Geol Surv Prof Pap, 554-D: 1-21.

Miller C D, 1989. Potential hazards from future volcanic eruptions in California. U S Geol Surv Bull, 1847: 1-17.

Sorey M L, Evans W C, Kennedy B M, Farrar C D, Hainsworth L J, Hausback B, 1998. Carbon dioxide and helium emissions from a reservoir of magmatic gas beneath Mammoth Mountain, California. J Geophys Res, 103: 15,303-15,323.

Mammoth Mountain, a trachydacitic lava-dome complex, lies on the SW topographic rim of Long Valley caldera. The 3369-m-high volcano lies west of the structural rim of the caldera and is considered to represent a magmatic system distinct from Long Valley caldera and the Inyo Craters (Hildreth, 2004). The latest magmatic eruptions at Mammoth Mountain took place about 57,000 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 SW of Mammoth Mountain and SE of Devils Postpile National Monument. The cones, whose name derives from colorful mantling scoria deposits, are unglaciated and were radiocarbon dated at about 8900 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 unrest, including seismicity, gas emission, and tree kill, is thought to be related to dike intrusion beneath Mammoth Mountain in 1989.