AVO Logo
Site Map | FAQ |
Alaska Volcano Observatory
Summary | Webcams | Webicorders | RSAM | Activity Notifications | Notification Search | Cleveland | Shishaldin | Semisopochnoi 
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

ALASKA VOLCANO OBSERVATORY

Weekly Update

Friday, October 6, 2006 12:30 PM AKDT (2030 UTC)




FOURPEAKED VOLCANO (CAVW#1102-26-)

58°46'12" N153°40'19" W, Summit Elevation 6903 ft (2104 m)

Current Level of Concern Color Code: YELLOW

Current Volcanic Activity Alert Level: Advisory



Volcanic unrest continues at Fourpeaked volcano. A seismometer installed on September 25 indicates that low-level seismicity at Fourpeaked has been ongoing throughout the week. Because we have only one station close enough to the volcano to detect most of these earthquakes, we are unable to locate them. An earthquake swarm on October 3 contained tens to hundreds of very small earthquakes.



Airborne gas measurements made on September 30 showed that high emission rates of sulfur dioxide continue at levels similar to those measured during the previous week. Poor weather has prevented any further field work.



Observations suggest the presence of new magma at shallow levels beneath the volcano. It remains possible that a significant eruption could occur in the coming days to months.



As weather allows, AVO will obtain further airborne gas measurements, install additional instrumentation, retrieve time-lapse images, and conduct further geologic investigations near the volcano.



Fourpeaked volcano is not known to have erupted historically and the age of the last eruption is not known. Geological investigations have been limited and ice covers much of the area. Because of this, the range of sizes and styles of past eruptions are not well-constrained. However, the composition of the volcano indicates that eruptions of Fourpeaked can be explosive, possibly producing plumes that reach in excess of 10 km (33,000 ft) above sea level and local ashfall.



Fourpeaked Mountain lies within the northeast corner of Katmai National Park and Preserve on the Alaska Peninsula, 7.5 miles (12 km) southwest of Mount Douglas. It is the likely vent for Fourpeaked volcano, a stratovolcano that is mostly surrounded (and covered) by Fourpeaked Glacier. Small isolated volcanic exposures along ridge crests and cliff faces radiate out from the ice-covered summit.



CLEVELAND VOLCANO (CAVW#1101-24-)

52°49'24" N169°56'35" W, Summit Elevation 5676 ft (1730 m)

Current Level of Concern Color Code: YELLOW

Current Volcanic Activity Alert Level: Advisory



Cleveland has been obscured by clouds during most of the past week, preventing satellite views of the volcano.



There is no real-time seismic network at Cleveland and AVO is unable to track local earthquake activity that may indicate volcanic unrest. Short-lived ash explosions may occur without warning and may go undetected on satellite imagery. Should significant activity send ash above 20,000 feet, detection by satellite is more likely.



Cleveland volcano forms the western half of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. It is located about about 75 km (45 mi.) west of the community of Nikolski, and 1500 km (940 mi.) southwest of Anchorage. The volcano's most recent significant eruption began in February, 2001 and had 3 explosive events that produced ash clouds as high as 12 km (39,000 ft) above sea level. This eruption also produced a rubbly lava flow and hot avalanche that reached the sea. The most recent minor ash emissions were observed in May 2006.



VENIAMINOF VOLCANO (CAVW#1102-07-)

56°11'44" N159°23'18" W, Summit Elevation 8225 ft (2507 m)

Current Level of Concern Color Code: YELLOW

Current Volcanic Activity Alert Level: Advisory



During this past week, seismicity at Veniaminof remained low, but above background. Cloudy weather persisted for much of the week, however one clear web camera view showed a small, white steam plume and no signs of ash emission.



Intermittent, short-lived, very small-volume steam and ash bursts from the intracaldera cone have been common over the past few years. Ash from these events is not likely to extend beyond the caldera rim. There are no indications that a larger eruption is imminent.



Mount Veniaminof volcano is an andesitic stratovolcano with an ice-filled 10-km diameter summit caldera located on the Alaska Peninsula, 775 km (480 mi) southwest of Anchorage and 35 km (22 mi) north of Perryville. Veniaminof is one of the largest (~ 300 km3) and most active volcanic centers in the Aleutian Arc and has erupted at least 13 times in the past 200 years. Recent significant eruptions of the volcano occurred in 1993-95 and 2005. Both were moderate Strombolian eruptions producing intermittent low-level jets of incandescent lava fragments, and low-level emissions of steam and ash from the main intracaldera cone. During the 1993-95 activity, a small lava flow was extruded into the summit caldera ice field producing an ice pit. Minor ash-producing explosions occurred in 2002, 2004, early 2005, and in recent weeks. Previous historical eruptions have produced ash plumes that reached 6,000 m (20,000 ft) above sea level and ash fallout that blanketed areas within about 40 km (25 mi) of the volcano.



OTHER ALASKA VOLCANOES



Seismic activity is monitored in real time at 30 volcanoes in Alaska. Satellite images of all Alaskan volcanoes are analyzed daily for evidence of ash plumes and elevated surface temperatures. Some volcanoes may currently display anomalous behavior but are not considered to be at a dangerous level of unrest. Wrangell, Spurr, Redoubt, Iliamna, Augustine, Snowy, Griggs, Katmai, Novarupta, Trident, Mageik, Martin, Peulik, Ukinrek Maars, Aniakchak, Pavlof, Dutton, Isanotski, Shishaldin, Fisher, Westdahl, Akutan, Makushin, Okmok, Korovin, Great Sitkin, Kanaga, Tanaga, and Gareloi volcanoes are in color code GREEN. All are at or near normal levels of background seismicity. AVO did not detect ash plumes or significant elevated surface temperatures in the vicinity of any volcano.



Please see http://www.avo.alaska.edu/color_codes.php for complete definitions of Aviation color codes and Volcanic activity alert levels.



VOLCANO INFORMATION ON THE INTERNET: http://www.avo.alaska.edu

RECORDING ON THE STATUS OF ALASKA'S VOLCANOES (907) 786-7478



CONTACT INFORMATION:

Tom Murray, Scientist-in-Charge, USGS

tlmurray@usgs.gov (907) 786-7497



Steve McNutt, Acting Coordinating Scientist, UAF

steve@giseis.alaska.edu (907) 474-7131



The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.
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