Iliamna


Facts


  • Official Name: Iliamna Volcano
  • Seismically Monitored: Yes
  • Color Code: GREEN
  • Alert Level: NORMAL
  • Elevation: 3053m (10016ft)
  • Latitude: 60.0319
  • Longitude: -153.0918
  • Smithsonian VNum: 313020
  • Pronunciation:
  • Nearby Towns:
    • Pedro Bay 39 mi (63 km) SW
    • Port Alsworth 44 mi (70 km) NW
    • Anchor Point 47 mi (76 km) SE
    • Happy Valley 47 mi (76 km) SE
    • Ninilchik 49 mi (79 km) NE

    Distance from Anchorage: 136 mi (218 km)

  • Subfeatures:
    • Johnson Glacier
    • South Twin

Description

From Miller and others (1998) [1] : "Iliamna volcano is a broad, deeply dissected and highly altered, roughly cone-shaped mountain at the north end of a 5-km-long ridge trending N10W. Most of the volcano is covered by perennial snow and ice and numerous glaciers radiate from the summit area. Large avalanche deposits occur on the flanks of the volcano, particularly down the Umbrella Glacier on the southwest side of the volcano.
"The volcano is a typical composite stratovolcano composed of interbedded andesite lava flows and pyroclastic rocks. Steep, inaccessible 600-m-high headwalls along the southern and eastern flanks extend nearly to the summit exposing a cross section of the volcanic stratigraphy.
"Iliamna is built on a basement of Jurassic granitic rocks of the Aleutian Range batholith [2] that are juxtaposed against older, Lower Jurassic lava flows and pyroclastic rocks by the Bruin Bay fault, which lies several kilometers east of the summit."

Name Origin

Iliamna Volcano's name was first published by the Russians as "S[opka] Ilymna" (Tebenkov, 1852). This appears to be the volcano called "Volcan de Miranda" by the 1779 Don Ignacio Arteaga expedition, which was probably named in honor of Fernando Bernardo de Quiros y Miranda, the second officer of the vessel La Princesa. The nearby Iliamna Lake, according to G.C. Martin, gets its name from the name of a "mythical great blackfish, supposed to inhabit this lake, which bites holes in the bidarkas of bad natives" (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] Geology of Iniskin-Tuxedni region, Alaska, 1966

Detterman, R. L., and Hartsock, J. K., 1966, Geology of Iniskin-Tuxedni region, Alaska: U.S. Geological Survey Professional Paper PP 0512, 78 p., 6 sheets, scale 1:63,360, 1:96,000, 1:1,000,000.
full-text PDF 4.6 MB
plate 1 PDF 15 MB
plate 2 PDF 1.7 MB
plate 3 PDF 2.5 MB
plate 4 PDF 376 KB
plate 5 PDF 606 KB
plate 6 PDF 192 KB

Current Activity

No new updates for Iliamna volcano since June 9, 2023, 11:53 am.

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