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Semisopochnoi: Color Code ORANGE Alert Level WATCH
Local time: February 08, 2023 1442 AKST (February 08, 2023 2342 UTC)
SEMISOPOCHNOI LINKS

SAMPLES

OTHER LINKS

COLOR CODE TIMELINE

CODE DEFINITIONS
ORANGE: Volcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway with no or minor volcanic-ash emissions [ash-plume height specified, if possible].
WATCH: Volcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway but poses limited hazards.
More information on color/alert definitions

AVO monitors seismic activity at potentially active volcanoes across Alaska and calculates locations and magnitudes for earthquakes (typically magnitude 3.0 and below) near the 32 active volcanoes where AVO operates seismic networks.

A geophysicist reviews each location and magnitude before it is released, therefore AVO’s locations may not be available for up to 2 or 3 days after the event, although larger earthquakes can be processed sooner.

Other organizations such as the Alaska Earthquake Center (AEC) at the University of Alaska Fairbanks Geophysical Institute (UAF/GI) and the USGS National Earthquake Information Center (NEIC) also locate the larger (magnitude >2.5) earthquakes.Because each organization uses slightly different techniques to calculate locations and magnitudes, the initial published locations and magnitudes may differ slightly for the same earthquake. The Advanced National Seismic System (ANSS) coordinates earthquake information from these organizations and keeps the Comprehensive Earthquake Catalog, a publicly available archive with detailed and complete information on all located earthquakes nation-wide: earthquake.usgs.gov/data/comcat/

SEMISOPOCHNOI UPDATES
ORANGE/WATCH 02-08-2023 12:08 - Daily Update
ORANGE/WATCH 02-07-2023 11:00 - Daily Update
ORANGE/WATCH 02-06-2023 11:45 - Daily Update
ORANGE/WATCH 02-05-2023 08:42 - Daily Update
ORANGE/WATCH 02-04-2023 11:47 - Daily Update
ORANGE/WATCH 02-03-2023 11:26 - Weekly Update
ORANGE/WATCH 02-02-2023 11:39 - Daily Update
ORANGE/WATCH 02-01-2023 11:16 - Daily Update

All Semisopochnoi Reports

Color Code and Alert Level Definitions

ASHFALL AND ASH CLOUD FORECASTS: MODEL OUTPUT
Mathematical models developed by the USGS forecast various aspects of how a volcanic ash plume will interact with wind—where, how high, and how fast ash particles will be transported in the atmosphere, as well as where ash will fall out and accumulate on the ground. AVO runs these models when a volcano is restless by assuming a reasonable hypothetical eruption, to provide a pre-eruptive forecast of areas likely to be affected. During an ongoing eruption, AVO will update the forecast with actual observations (eruption start time and duration, plume height) as they become available. Click on individual graphics to learn more.
ASHFALL FORECASTS
NONE
ASH CLOUD FORECASTS (AIRBORNE):
NONE
THESE PRODUCTS MAY NOT BE CURRENT.
During an actual eruption, see National Weather Service forecasts of airborne ash hazard to aircraft (SIGMETS: https://weather.gov/aawu/ and Volcanic Ash Advisories: https://weather.gov/vaac) as well as forecasts of ash fall: https://weather.gov/afc.
INSTRUMENT DATA

SELECTED IMAGES
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Semisopochnoi index map
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May 30, 2021, H. Dietterich, USGS/AVO
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May 29, 2021, W. Mayo, DGGS/AVO
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April 22, 2021
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Eruption plume from Semisopochnoi, courtesy of Nora Rojek, R/V Tiglax, August 3, 2021.
View all images of this event
LINKS
Contact AVO Privacy Accessibility Information Quality FOIA
URL: www.avo.alaska.edu/activity/Semisopochnoi.php
Page modified: December 21, 2022 18:26
Contact Information: AVO Web Team

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