Photo of this volcano
Google Earth icon
Google Earth Placemark
  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 58.354°N
  • 155.092°W

  • 2317 m
    7600 ft

  • 312190
  • Latitude
  • Longitude

  • Summit

  • Volcano

There are no activity reports for Griggs.

 Available Weekly Reports

There are no Weekly Reports available for Griggs.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1790 BCE ± 40 years Unknown Confirmed   Radiocarbon (corrected)

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.

Fierstein J, 2007. Explosive eruptive record in the Katmai region, Alaska Peninsula: an overview. Bull Volc, 69: 469-509.

Henning R A, Rosenthal C H, Olds B, Reading E (eds), 1976. Alaska's volcanoes, northern link in the ring of fire. Alaska Geog, 4: 1-88.

Hildreth W, 1987. New perspectives on the eruption of 1912 in the Valley of Ten Tousand Smokes, Katmai National Park, Alaska. Bull Volc, 49: 680-693.

Hildreth W, Fierstein J, 2000. Katmai volcanic cluster and the great eruption of 1912. Geol Soc Amer Bull, 112: 1594-1620.

Hildreth W, Fierstein J, Lanphere M A, Siems D F, 2002. Mount Griggs: a compositionally distinctive Quaternary stratovolcano behind the main volcanic line in Katmai National Park. In: Wilson R H, Galloway J P (eds), Geologic Studies in Alaska by the U. S. Geological Survey, 2000 {U S Geol Surv Prof Pap}, 1662: 87-112.

Hildreth W, Lanphere M A, Fierstein J, 2003b. Geochronology and eruptive history of the Katmai volcanic cluster, Alaska Peninsula. Earth Planet Sci Lett, 214: 93-114.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Motyka R J, Liss S A, Nye C J, Moorman M A, 1993. Geothermal resources of the Aleutian arc. Alaska Div Geol Geophys Surv, Prof Rpt, no 114, 17 p and 4 map sheets.

Wood C A, Kienle J (eds), 1990. Volcanoes of North America. Cambridge, England: Cambridge Univ Press, 354 p.

The summit of Mount Griggs towers above Knife Creek on the NE side of the Valley of Ten Thousand Smokes. The volcano is uniquely offset west of the NE-trending alignment of volcanoes in the Katmai area. The broad, 2317-m-high stratovolcano, formerly known as Knife Peak, consists of a late-Pleistocene volcano with glacial valleys on the north that was truncated on its SW side by an early Holocene edifice collapse. A Holocene volcano was subsequently constructed within the 1.5-km-wide scarp left by the emplacement of a large SW-flank debris avalanche. Nested cones with three concentric craters mostly fill the scarp, and thick, blocky lava flows blanket the SW flanks of the volcano below the collapse scarp. In contrast to the more silicic centers of the Katmai area along the crest of the range, lava flows from Griggs are dominantly andesitic in composition, and dacitic lava flows are uncommon. No historical eruptions have occurred from Griggs, but noisy fumarolic jets near the summit can be heard from the valley floor, 1750 m below.