Mount Griggs, formerly known as Knife Peak Volcano, is a stratovolcano, which lies 10 km behind the volcanic arc defined by other Katmai group volcanoes. Although no historic eruptions have been reported from Mount Griggs, vigorously active fumaroles persist in a summit crater and along the upper southwest flank. The fumaroles on the southwest flank are the hottest, and some of the flank fumaroles can roar so loudly that they can be heard from the valley floor.[1] The slopes of Mount Griggs are heavily mantled by fallout from the 1912 eruption of Novarupta volcano.[3] The summit consists of three concentric craters, the lowest and largest of which contains a recent summit cone topped by two craters. The volume of the volcanic edifice is estimated at about 25 cubic kilometers (6.0 cu mi). Isotopic analysis indicates that the source of Griggs' magma is distinct from the other Katmai volcanoes.[4]

Mount Griggs
NW view from west rim of Katmai caldera, July 1990
Highest point
Elevation7,602 ft (2,317 m) [1]
Prominence7,300 ft (2,200 m)
Coordinates58°21′26″N 155°06′13″W / 58.3572°N 155.1037°W / 58.3572; -155.1037Coordinates: 58°21′26″N 155°06′13″W / 58.3572°N 155.1037°W / 58.3572; -155.1037[2]
Mount Griggs is located in Alaska
Mount Griggs
Mount Griggs
LocationKatmai National Park and Preserve, Lake and Peninsula Borough, Alaska, U.S.
Parent rangeAleutian Range
Topo mapUSGS Mount Katmai B-4
Mountain typeStratovolcano
Volcanic arc/beltAleutian Arc
Last eruption1790 BCE ± 40 years

The mountain was named for Dr. Robert Fiske Griggs (1881–1962), botanist, whose explorations of the area, after the eruption of Mount Katmai in 1912, led to the creation of Katmai National Monument by President Woodrow Wilson in 1918.[5]

Map showing volcanoes of Alaska with the mark set at the location of Mount Griggs

See alsoEdit


  1. ^ a b "Griggs". Global Volcanism Program. Smithsonian Institution. Retrieved 2010-03-30.
  2. ^ "Griggs". Alaska Volcano Observatory. Retrieved 2010-03-30.
  3. ^ "Volcanoes of the Alaska Peninsula and Aleutian Islands-Selected Photographs - Album". U.S. Geological Survey. Retrieved 2010-03-30.
  4. ^ "Mount Griggs description and information". Alaska Volcano Observatory. U.S. Geological Survey. Retrieved 20 February 2019.
  5. ^ "Mount Griggs". Geographic Names Information System. United States Geological Survey. Retrieved 2010-03-30.

External linksEdit