AVO Logo
Site Map | FAQ |
Alaska Volcano Observatory
Summary | Webcams | Webicorders | RSAM | Activity Notifications | Notification Search | Cleveland | Shishaldin | Pavlof 
You are here: Home > Current Volcanic Activity > Archived Volcano Activity Notifications

AVO Archived Volcano Activity Notifications

2007
December
November
October
September
August
July
June
May
April
March
February
January
2006
December
November
October
September
August
July
June
May
April
March
February
January
2005
December
November
October
September
August
July
June
May
April
March
February
January
2004
December
November
October
September
August
July
June
May
April
March
February
January
2003
2002
2001
2000
1999
1998
1997
1996
December
November
October
September
August
July
June
May
April
March
February
January
1995
1994
1993
1992
December
November
October
September
August
July
June
May
April
March
February
January
1991
1990
1989
ARCHIVED REPORT
Printer friendly version

ILIAMNA



False Alarm:



On 30 April, a pilot report of a "plume to 20,000 ft over Iliamna Volcano" gave rise to a snowballing reaction within the aviation community. The nonevent culminated in the issuance of an AVO Information Release stating that no eruptive activity was occurring at any Cook Inlet Volcano and that sightings of intense steam clouds in combination with spring weather systems were common at this time of year.

AVO Anchorage received a message on the recorder from the Weather Desk at Anchorage Center (FAA) inquiring about activity at Iliamna. A return call at 1000 yeilded the information that a PIREP of a "20,000-ft plume" had prompted issuance of an air traffic advisory and that flights were being rerouted to well above and around Iliamna. AVO Anchorage quickly verified no change in seismicity and reported this information to the FAA. A subsequent report of a plume over Redoubt necessitated a similar callback.

By later that afternoon, erroneous word of a possible eruption had spread to the Air National Guard, some airlines, and Kenai Emergency Services. Calls from the Drift River Oil Terminal and the Anchorage Airport Tower prompted AVO Anchorage to again check seismicity and the slow-scan TV display - a clear view of both volcanoes showed typical quiescent steam plumes rising at most 300m (1000 ft) above the volcanoes. Transient weather clouds added altitude to the cloudforms which, we expect, were misinterpreted by pilots.

Around 1630, AVO Anchorage received a flurry of calls from several TV stations, Federal Express, and Elmendorf personnel about the "eruption of Iliamna and the ash cloud heading for Anchorage". Someone at Elmendorf reported hearing this news on TV and said that base personnel were making plans to get children and aircraft indoors. After explaining the situation to critical contacts over the phone, AVO decided to issue a written statement emphasizing the no eruption had occurred.

VOLCANO ALERT LEVELS
NORMAL
Volcano is in typical background, noneruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to noneruptive background state.
ADVISORY
Volcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.
WATCH
Volcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway but poses limited hazards.
WARNING
Hazardous eruption is imminent, underway, or suspected.

AVIATION COLOR CODES
GREEN
Volcano is in typical background, noneruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to noneruptive background state.
YELLOW
Volcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.
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].
RED
Eruption is imminent with significant emission of volcanic ash into the atmosphere likely OR eruption is underway or suspected with significant emission of volcanic ash into the atmosphere [ash-plume height specified, if possible].

PDF version of these definitions
Contact AVO Privacy Accessibility Information Quality FOIA
URL: avo.alaska.edu/activity/avoreport_archives.php
Page modified: May 27, 2014 10:23
Contact Information: AVO Web Team

twitter @alaska_avo
facebook alaska.avo
email Receive volcano updates by email: USGS VNS