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Tue, Oct. 3, 2023-12:44:46am
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Tue, Oct 3, 2023 - 12:51am |
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Volcanic Descriptions
- Volcano Alert Levels Description
- Aviation Color Codes Description
- Volcanic Eruption: Major Types
- Types of Volcanoes
Description
From Miller et al (1998): "Redoubt Volcano is a steep-sided cone about 10 km in diameter at its base and with a volume of 30-35 cubic kilometers. The volcano is composed of intercalated pyroclastic deposits and lava flows and rests on Mesozoic granitic rocks of the Alaska-Aleutian Range batholith (Till and others, 1993; 1994). It has been moderately dissected by the action of numerous alpine glaciers. A 1.8-km-wide, ice-filled summit crater is breached on the north side by a northward-flowing glacier, informally known as the Drift Glacier, which spreads into a piedmont lobe in the upper Drift River Valley. The most recently active vent is located on the north side of the crater at the head of the Drift glacier. Holocene lahar deposits in the Crescent River and Drift River valleys extend downstream as far as Cook Inlet."
ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
U.S. Geological Survey
Monday, October 2, 2023, 12:42 PM AKDT (Monday, October 2, 2023, 20:42 UTC)
SHISHALDIN (VNUM #311360)
54°45'19" N 163°58'16" W, Summit Elevation 9373 ft (2857 m)
Current Volcano Alert Level: WATCH
Current Aviation Color code: ORANGE
Low-level volcanic activity continues at Shishaldin Volcano. Seismicity continues at low levels and no explosions have been detected in infrasound data over the past day. Weakly elevated surface temperatures were observed in satellite data reflecting cooling deposits from the last explosive event a week ago.
There have been eleven periods of elevated eruptive activity that resulted in significant ash emissions, edifice collapses events of the summit cone, and mass flows of volcanic debris on the volcano's flanks since the onset of the current eruption. These periods of elevated eruptive activity have been preceded by increases in seismicity in the hours to days before they occur. Additional collapse of accumulated lava near the summit crater can occur without warning and generates hot mass flows on the upper flanks and small volcanic ash clouds that dissipate quickly. The ongoing eruption started on July 12, and it is unknown how long this episode will last. However, previous eruptions of Shishaldin Volcano have lasted weeks to months with repeated cycles of activity like those seen since July.
Local seismic and infrasound sensors, web cameras, and a geodetic network monitor Shishaldin Volcano. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lighting data, and satellite images to detect eruptions.
GREAT SITKIN (VNUM #311120)
52°4'35" N 176°6'39" W, Summit Elevation 5709 ft (1740 m)
Current Volcano Alert Level: WATCH
Current Aviation Color code: ORANGE
Slow eruption of lava in the summit crater likely continues. Seismicity remains low with a few earthquakes detected over the past day. Cloudy conditions obscured satellite and web camera images.
The current lava flow at Great Sitkin Volcano began erupting in July 2021. No explosive events have occurred since a single event in May 2021.
Local seismic and infrasound sensors, web cameras, regional infrasound and lightning networks, and satellite data are used to monitor the volcano.
TRIDENT (VNUM #312160)
58°14'3" N 155°6'9" W, Summit Elevation 3599 ft (1097 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color code: YELLOW
Seismic activity near Trident Volcano was low with a few local earthquakes detected over the past day. No volcanic activity was noted in clear satellite or web camera images, although resuspended ash from the 1912 eruption of Katmai is visible in the region.
The current period of seismic unrest began on August 24, 2022. Increases in seismic activity have been detected previously at Trident Volcano and other similar volcanoes and did not result in eruptions. We expect additional shallow seismicity and other signs of unrest, such as gas emissions, elevated surface temperatures, and ground movement, to precede any future eruption if one were to occur. AVO issued an Information Statement on July 25 providing a more detailed update on the volcanic unrest at Trident Volcano and the broader Katmai volcanic cluster (https://www.avo.alaska.edu/news.php?id=1595).
Trident Volcano is monitored by local seismic sensors, web cameras, regional infrasound and lightning networks, and satellite data.
Source: Alaska Volcano Observatory
This is a static image of Mount Redoubt,
The VolcanoCam image automatically updates approximately every two hours.
Volcano image courtesy of ...
Live webcam images of various Alaskan volcanoes
Alaska Volcano Observatory Webcam - Redoubt - DFR
Images of Mount Redoubt |
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Gallery 1 | Gallery 2 |
U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.
- USGS Cascades Volcano Observatory
- Cascade Range Current Update
- USGS Alert-Notification System for Volcanic Activity
- Volcano Observatories: Alaska
- Volcano Observatories: Cascades
- Volcano Observatories: Hawaii
- Volcano Observatories: Long Valley
- Volcano Observatories: Mariana Islands
- Volcano Observatories: Yellowstone
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