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Edgecumbe

Photo of this volcano
  • Country
  • Landform (Volc Type)
  • Last Known Eruption
  • 57.05°N
  • 135.75°W

  • 970 m
    3182 ft

  • 315040
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Weekly Report: 20 April-26 April 2022 Citation IconCite this Report

AVO stated that a seismic swarm beneath Kruzof Island near Edgecumbe that began at about 0200 on 11 April had declined to background levels by 22 April. The swarm prompted an in-depth analysis of satellite data which spanned the last 7.5 years. The data showed that a broad area of uplift, about 17 km in diameter, was located about 2.5 km E of Edgecumbe. The uplift began in August 2018 and deformed at a rate of up to 8.7 cm per year in the center of the area, totaling 27 cm of uplift; the deformation was ongoing. Retrospective analysis of seismic data revealed that earthquakes started occurring in 2020, though the recent swarm was unusual. The deformation and seismic data together suggested magma movement beneath the volcano, consistent with an intrusion at about 5 km below sea level. The closest seismic station to the volcano was on Sitka, 24 km E; both the Volcano Alert Level and Aviation Color Code remained at Unassigned due to the lack of dedicated, local instrumentation.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Weekly Reports - Index


2022: April


20 April-26 April 2022 Citation IconCite this Report

AVO stated that a seismic swarm beneath Kruzof Island near Edgecumbe that began at about 0200 on 11 April had declined to background levels by 22 April. The swarm prompted an in-depth analysis of satellite data which spanned the last 7.5 years. The data showed that a broad area of uplift, about 17 km in diameter, was located about 2.5 km E of Edgecumbe. The uplift began in August 2018 and deformed at a rate of up to 8.7 cm per year in the center of the area, totaling 27 cm of uplift; the deformation was ongoing. Retrospective analysis of seismic data revealed that earthquakes started occurring in 2020, though the recent swarm was unusual. The deformation and seismic data together suggested magma movement beneath the volcano, consistent with an intrusion at about 5 km below sea level. The closest seismic station to the volcano was on Sitka, 24 km E; both the Volcano Alert Level and Aviation Color Code remained at Unassigned due to the lack of dedicated, local instrumentation.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


13 April-19 April 2022 Citation IconCite this Report

AVO stated that a seismic swarm beneath Kruzof Island near Edgecumbe began at about 0200 on 11 April, and by 15 April several hundred earthquakes had been recorded. The number of events was unusual for that volcano. The magnitudes were generally M 1.7 or smaller, though a M 2.8 was detected on 11 April. The events were located at depths of less than 10 km, though the exact locations were difficult to constrain due to the lack of a local seismic network on the island; the closest station was in Sitka, 25 km E. The source of the swarm was unknown, and related either to tectonic processes or volcanic unrest, or a combination of both. Both the Volcano Alert Level and Aviation Color Code were Unassigned due to the lack of dedicated, local instrumentation. AVO noted that additional data from distant seismic stations was being analyzed, and several years of Synthetic Aperture Radar (SAR) data was being evaluated for topographical changes. No surficial changes were visible in recent satellite images and webcams views.

Source: US Geological Survey Alaska Volcano Observatory (AVO)


The Global Volcanism Program has no Bulletin Reports available for Edgecumbe.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 4 confirmed Holocene eruptive periods.

2360 BCE ± 140 years - 2080 BCE ± 90 years Confirmed Eruption  

Episode 1 | Eruption Episode Edgecumbe Second Mid-Holocene Rhyolitic Ash
2360 BCE ± 140 years - 2080 BCE ± 90 years Evidence from Isotopic: 14C (uncalibrated)
 The younger of two phreatomagmatic tephras from Edgecumbe is 14C dated at 4,030 ± 90 and 4,310 ± 140 BP from peat above and below the tephra (Riehle and Brew 1984; Riehle, in Wood and Kienle 1990).

List of 1 Events for Episode 1 at Edgecumbe Second Mid-Holocene Rhyolitic Ash

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion

3810 BCE ± 70 years Confirmed Eruption  

Episode 1 | Eruption Episode Edgecumbe Mid-Holocene Rhyolitic Tephra
3810 BCE ± 70 years - Unknown Evidence from Isotopic: 14C (uncalibrated)
 The lower of two phreatomagmatic tephras from Edgecumbe was 14C dated at 5,760 ± 70 yrs BP from peat enclosing the tephra (Riehle and Brew, 1984; Riehle et al., 1992).

List of 1 Events for Episode 1 at Edgecumbe Mid-Holocene Rhyolitic Tephra

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion

7215 BCE ± 165 years Confirmed Eruption  

Episode 1 | Eruption Episode Edgecumbe CFE
7215 BCE ± 165 years - Unknown Evidence from Isotopic: 14C (uncalibrated)
 14C dates of 9,180 and 9,150 ± 150 BP from a stump within a pumice-bearing lahar deposit (Brew et al., 1969; Riehle and Brew, 1984).

List of 5 Events for Episode 1 at Edgecumbe CFE

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Explosion
   - - - -    - - - - Ash
   - - - -    - - - - Lapilli
   - - - -    - - - - Pumice
   - - - -    - - - - Lahar or Mudflow

9300 BCE ± 50 years Confirmed Eruption  

Episode 1 | Eruption Episode Edgecumbe Tephra set (includes Mount Edgecumbe Dacite (MEd) Tephra)
9300 BCE ± 50 years - Unknown Evidence from Isotopic: 14C (uncalibrated)
Deformation History

There is no Deformation History data available for Edgecumbe.

Emission History

There is no Emissions History data available for Edgecumbe.

GVP Map Holdings

Maps are not currently available due to technical issues.

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included.

Smithsonian Sample Collections Database

There are no samples for Edgecumbe in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites