Iliamna volcano

Updated: Aug 12, 2022 06:10 GMT - Refresh
stratovolcano 3053 m / 10,016 ft
Cook Inlet (SW Alaska), 60.03°N / -153.09°W
Current status: normal or dormant (1 out of 5)
Last update: 15 Dec 2021
The summit of Iliamna volcano with active fumaroles (photo: Tina Neal, Alaska Volcano Observatory / USGS)
The summit of Iliamna volcano with active fumaroles (photo: Tina Neal, Alaska Volcano Observatory / USGS)

Iliamna volcano is a large stratovolcano on the western side of the Cook Inlet, in Lake Clark National Park 220 km SW of Anchorage or 100 km NW of Homer.
There are several uncertain reports about activity in the past 250 years, but the only confirmed known historical eruptions were small to moderate explosive eruptions in 1876, 1867, and between 778 and 1879. A larger eruption with pyroclastic flows was dated by radiocarbon method and occurred between 300 and 140 years ago, but was not observed. Most of the sparse eruption reports from Iliamna are probably referring to strong activity of fumaroles located east and SE of the summit.

Show interactive Map
[hide map] [enlarge]
Typical eruption style: explosive
Iliamna volcano eruptions: 1953(?), 1952(?), 1933(?), 1876, 1867, 1843(?), 1793(?), 1778-79, 1768(?)
radiocarbon-dated: 1650 ?, 450 BC ?, 2050 BC ?, 5050 BC ?
Lastest nearby earthquakes:
TimeMag. / DepthDistance/Location
Wednesday, August 10, 2022 GMT (1 quake)
Aug 10, 2022 2:28 am (GMT -8) (Aug 10, 2022 10:28 GMT)
1.3

155 km
26 km (16 mi)
37 Km NE of Pedro Bay, Alaska
Tuesday, August 2, 2022 GMT (3 quakes)
Aug 2, 2022 3:29 pm (GMT -8) (Aug 2, 2022 23:29 GMT)
2.2

143 km
24 km (15 mi)
39 Km ENE of Pedro Bay, Alaska
Aug 2, 2022 10:29 am (GMT -8) (Aug 2, 2022 18:29 GMT)
1.6

148 km
37 km (23 mi)
28 Km E of Pedro Bay, Alaska
Aug 2, 2022 7:42 am (GMT -8) (Aug 2, 2022 15:42 GMT)
2.5

151 km
42 km (26 mi)
27 Km E of Pedro Bay, Alaska

Background

Iliamna volcano has no distinct summit crater, but forms a flat top joined on the south by a 5 km long ridge with the prominent flank lava domes of North and South Twin Peaks. Another important flank vent is the Johnson Glacier dome on the NE flank.
Steep headwalls on the southern and eastern flanks expose an inaccessible cross-section of the volcano.
Several major glaciers radiate from its summit; the 4 largest together contain an estimated volume of 15 cubic km of ice.
Eruptions producing pyroclastic flows have been dated at as recent as about 300 and 140 years ago (into the historical period), and elevated seismicity accompanying dike emplacement beneath the volcano was recorded in 1996.

1996-97 earthquake swarms
During 1996-97, dike intrusions under the volcano caused several shallow earthquake swarms, but no eruption. ...more

1987 steam plume
On the morning of 19 March 1987 at 8am, several pilots observed an unusually large steam plume rising about 1000-1100 m above the summit of Iliamna. The plume originated from an area on the upper S flank vent, but did not contain visible ash.
The event is not counted as an eruption, but a period of exceptionally strong degassing from active fumaroles.

1978 steam eruption
A brief steam eruption occurred on 7 November 1978 between 10 and 13 h local time, producing puffs of steam, ejected every 1-5 minutes, that rose an estimated 3 km above the summit. No ash was visible in the steam puffs. No unusual seismic activity was recorded.

See also: Sentinel hub | Landsat 8 | NASA FIRMS
Locatioin map of Iliamna volcano (source: Alaska Volcano Observatory / Alaska Division of Geological & Geophysical Surveys)
Locatioin map of Iliamna volcano (source: Alaska Volcano Observatory / Alaska Division of Geological & Geophysical Surveys)
Try our free app!
Volcanoes & Earthquakes - new app for Android
Android | iOS version

More on VolcanoDiscovery

Why is there advertising on this site?
Support us - Help us upgrade our services!
We truly love working to bring you the latest volcano and earthquake data from around the world. Maintaining our website and our free apps does require, however, considerable time and resources.
We need financing to increase hard- and software capacity as well as support our editor team. We're aiming to achieve uninterrupted service wherever an earthquake or volcano eruption unfolds, and your donations can make it happen! Every donation will be highly appreciated. If you find the information useful and would like to support our team in integrating further features, write great content, and in upgrading our soft- and hardware, please make a donation (PayPal or Online credit card payment).

Planned features:
  • Improved multilanguage support
  • Tsunami alerts
  • Faster responsiveness
Thanks to your past donations, these features have been added recently:
  • Earthquake archive from 1900 onwards
  • Detailed quake stats
  • Additional seismic data sources
Download and Upgrade the Volcanoes & Earthquakes app to get one of the fastest seismic and volcano alerts online:
Android | IOS
Thank you!
Sources: VolcanoDiscovery / VolcanoAdventures and other sources as noted.
Use of material: Most text and images on our websites are owned by us. Re-use is generally not permitted without authorization. Contact us for licensing rights.
Volcanoes & Earthquakes
VolcanoDiscovery Home
Adventure & Study Travel
Tours to Volcanoes and Volcanic Areas: walking tours, photo tours, study tours Get our newsletter!
Company info
Contact | Legal info | Terms & conditions
Follow us
Follow us on facebook Follow us on Instagram Follow us on Twitter Visit our Youtube channel
EN | DE | EL | ES | FR | IT | RU
VolcanoDiscovery GmbH, Germany, Reg. nr.: HRB 103744, EU Tax Id: DE 310 395 322 owned and created by
Dr. Tom Pfeiffer, volcanologist, volcano photographer, tour organizer member of
IAVCEI
Volcanological Society
Ecotourism Greece
Insured by R+V
VolcanoDiscovery © 2004- All Rights Reserved | Privacy - cookie settings