• Official Name: Mount Spurr
  • Seismically Monitored: Yes
  • Color Code: GREEN
  • Alert Level: NORMAL
  • Elevation: 3374m (11069ft)
  • Latitude: 61.2989
  • Longitude: -152.2539
  • Smithsonian VNum: 313040
  • Pronunciation:
  • Nearby Towns:
    • Beluga 37 mi (60 km) SE
    • Tyonek 40 mi (65 km) SE
    • Nikiski 51 mi (81 km) SE
    • Susitna 55 mi (89 km) NE
    • Salamatof 56 mi (90 km) SE
  • Subfeatures:
    • Crater Peak


From Miller and others (1998) [1] : "Mount Spurr is a Quaternary stratovolcano located near the northeastern end of the Aleutian volcanic arc. It is the easternmost historically active volcano in the Aleutian arc and is the highest of several snow- and ice-covered peaks that appear to define a large, dissected stratovolcano [2] .
"Capps (1929) [3] suggested that a summit caldera, largely buried by ice, is associated with Mount Spurr. Later, Juhle and Coulter (1955) [2] disagreed with the caldera interpretation suggesting that the peaks around Mount Spurr only coincidentally resemble the rim of a large subsidence structure. Most recent studies, however, suggest that ancestral Mt. Spurr, constructed during late Pleistocene time [4] , was partially destroyed by a major Bezymianny-type eruption possibly as late as early Holocene time [5] [6] . The eruption produced a voluminous volcanic debris avalanche and subsequent pyroclastic flows that resulted in the formation of a 5- to 6-km-diameter explosion caldera. The volcanic debris avalanche contains blocks as much as 100 m in diameter and traveled a minimum of 25 km. The overlying pyroclastic flows are partially welded and are composed chiefly of high silica andesite. Present Mt. Spurr is the highest of several post-caldera, centrally located, ice-carved cones or domes.
"The youngest volcanic feature at Mount Spurr is a satellitic cone, Crater Peak, located in the breach in the caldera about 3.2 km south of Mount Spurr. Crater Peak has a summit crater that is itself slightly breached along the south rim; the north wall of the crater exposes the truncated remains of an older dome or lava lake. Crater Peak has been the source of all Late Holocene eruptive activity at Mt. Spurr [5] . Before the 1992 eruption, a small crater lake occupied the bottom of the crater."

Name Origin

A.H. Brooks named Mount Spurr in 1900, for Josiah Edward Spurr, a U.S. Geological Survey geologist who led an expedition in the area in 1898 (Orth, 1971).

References Cited

[1] Catalog of the historically active volcanoes of Alaska, 1998

Miller, T. P., McGimsey, R. G., Richter, D. H., Riehle, J. R., Nye, C. J., Yount, M. E., and Dumoulin, J. A., 1998, Catalog of the historically active volcanoes of Alaska: U.S. Geological Survey Open-File Report 98-0582, 104 p.

[2] The Mt. Spurr eruption, July 9, 1953, 1955

Juhle, R. W., and Coulter, H. W., 1955, The Mt. Spurr eruption, July 9, 1953: Eos, v. 36, n. 2, p. 199-202.

[3] The Mount Spurr region, Alaska, 1929

Capps, S. R., 1929, The Mount Spurr region, Alaska: U.S. Geological Survey Bulletin 0810-C, p. 141-172, 2 plates, scale 1:250,000.
full-text PDF 1.6 MB
plate 3 PDF 324 KB

[4] Geochronology of eruptive events at Mt. Spurr, Alaska, 1986

Turner, D. L., and Nye, C. J., 1986, Geochronology of eruptive events at Mt. Spurr, Alaska: in Turner, D. L. and Wescott, E. M., (eds.), Geothermal energy resource investigations at Mt. Spurr, Alaska, University of Alaska Fairbanks Geophysical Institute Report UAG-R 308, p. 20-27, 1 plate, scale 1:2,860.

[5] A reconnaissance of the major Holocene tephra deposits in the upper Cook Inlet region, Alaska, 1985

Riehle, J. R., 1985, A reconnaissance of the major Holocene tephra deposits in the upper Cook Inlet region, Alaska: Journal of Volcanology and Geothermal Research, v. 26, n. 1-2, p. 37-74.

[6] Petrology, geochemistry, and age of the Spurr volcanic complex, eastern Aleutian arc, 1990

Nye, C. J., and Turner, D. L., 1990, Petrology, geochemistry, and age of the Spurr volcanic complex, eastern Aleutian arc: Bulletin of Volcanology, v. 52, n. 3, p. 205-226.

Current Activity

April 4, 2024, 4:30 pm

Conditions at Mount Spurr volcano have improved and AVO is receiving data from earthquake monitoring stations and a remote web camera at the volcano 120 km (75 miles) west of Anchorage. Data are now sufficient to establish the state of the volcano. As a result, the Aviation Color Code and Volcano Alert Level are changed to GREEN/NORMAL. 


A thick winter snowpack prevented data transmission from seismic stations on Mount Spurr volcano to AVO in Anchorage.  

Conditions on the volcano have improved recently. In addition, following work at the Anchorage receive facility and some remote radio reconfigurations, AVO is reliably acquiring data from six stations of the Spurr Network. As a result, AVO can now track volcanic activity in real time and provide early warning of eruptive activity. 

AVO is also acquiring webcam images from station CKT. A field visit is planned for late April to make further improvements prior to a larger effort later in the summer of 2024 to improve network operations for next winter.


As days lengthen and more snowmelt occurs, data transmission will continue to improve and stabilize. A field visit planned for late April 2024 should further establish the network's functionality.

Activity and monitoring at Mount Spurr 

Though AVO’s monitoring is now restored, a plausible eruption scenario for Mount Spurr would involve months of elevated earthquake activity before an eruption. At present, Mount Spurr is not showing any signs of unrest. 

With the current monitoring network health, AVO is able to provide timely eruption forecasts and quickly confirm or dismiss reports of activity. In addition to seismic monitoring, AVO will use satellite data, regional seismic, infrasound and lightning networks, and reports from pilots and ground observers to detect signs of unrest or eruptive activity.



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