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

VOLCANO ACTIVITY NOTIFICATIONS

2014
2013
2012
2011
2010
2009
2008
2007

Older reports can be found here.

Report Text
Printer friendly version

ALASKA VOLCANO OBSERVATORY WEEKLY UPDATE
Friday, July 26, 2013 11:23 AM AKDT (Friday, July 26, 2013 19:23 UTC)


VENIAMINOF VOLCANO (CAVW #1102-07-)
56°11'52" N 159°23'35" W, Summit Elevation 8225 ft (2507 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Nearly continuous, gradually fluctuating volcanic tremor and occasional explosions have been observed in seismic data from Veniaminof Volcano throughout the past week. Elevated surface temperatures at the intracaldera cone also have been observed in satellite data throughout the past week. When viewing conditions permit, incandescence at the cone has been observed in night-time web camera views. Day time web camera views also showed that low-level ash and steam emissions have continued throughout the week. A pilot report from 8:00 AM AKDT July 25 described an ash plume to 200-300 feet above the erupting cone and dispersing 15 miles to the south and a "river of lava" flowing from the intracaldera cone.

Over the past week, the low-level eruptive activity characterized by intermittent effusion of lava and emission of minor amounts of ash and steam has continued. Ash emissions have been very minor and rates of lava effusion have fluctuated slightly throughout the week. This level of activity may persist for several more weeks to months. AVO has observed nothing in any of the data streams we monitor to indicate that the eruption will intensify and become more explosive; however, this remains a possibility. Continued production of lava may result in more melting of the ice and snow in the vicinity of the cone, but thus far there is no evidence for outflow of water down Cone Glacier to the north of the cone.

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, November 2006, and February 2008. 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.

PAVLOF VOLCANO (CAVW #1102-03-)
55°25'2" N 161°53'37" W, Summit Elevation 8261 ft (2518 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Seismicity has remained at low levels throughout the past week. Elevated surface temperatures, consistent with cooling lava flows, were detected in satellite data over the past week, although, views of the volcano in satellite data and in the Cold Bay web camera were often obscured by clouds. No ash or gas emissions have been detected in satellite data, web camera images, or reported by pilots this week.

It has now been 28 days since the last period of ash emission and lava fountaining at Pavlof Volcano. The continued low-level of seismic activity, and the cessation of lava fountaining and ash emission suggests that the 2013 eruption may have ended. However, it remains possible for eruptive activity to resume at any time and the degree of seismic activity remains above background levels. During the 1984-86 eruption there were periods of several weeks to months where seismic activity declined to low levels and was later followed by explosive activity and lava fountaining.

Pavlof volcano is located on the southwestern end of the Alaska Peninsula. Pavlof is a stratovolcano which rises to an elevation of 8262 feet. With almost 40 historic eruptions, it is one of the most consistently active volcanos in the Aleutian arc. Eruptive activity is generally characterized by sporadic strombolian fountaining continuing for a several-month period. The community of Cold Bay is located 60 km (37 miles) to the southwest of Pavlof.

CLEVELAND VOLCANO (CAVW #1101-24-)
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Elevated surface temperatures were detected at the summit of Cleveland Volcano intermittently in satellite data over the past week. A distinct plume was observed in satellite imagery from 07:22 AM AKDT (15:22 UTC) July 24 until 5:24 PM AKDT (1:24 UTC July 25) that extended to the southwest about 100 miles. No ash signal was detected in satellite data, thus it is likely that the plume was composed primarily of steam and gas. Views of the summit in the Nikolski web camera were occasionally clear, but nothing unusual was observed throughout the week. AVO has received no other reports of activity at the volcano.

Cleveland volcano forms the western half of Chuginadak Island, a remote and uninhabited island in the east central Aleutians. It is located 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 it produced 3 explosive events that produced ash clouds as high as 12 km (39,000 ft) above sea level. The 2001 eruption also produced a rubbly lava flow and hot avalanche that reached the sea. The most recent minor ash emissions were observed in November 2012.

OTHER ALASKA VOLCANOES

Seismic activity is monitored in real time at 29 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. Akutan, Aniakchak, Augustine, Dutton, Fisher, Fourpeaked, Gareloi, Great Sitkin, Griggs, Iliamna, Isanotski, Kanaga, Katmai, Mageik, Makushin, Martin, Novarupta, Okmok, Redoubt, Shishaldin, Snowy, Spurr, Tanaga, Trident, Ugashik-Peulik, Ukinrek Maars, and Westdahl volcanoes are in color code GREEN and volcano alert level Normal. 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 of these volcanoes.

Please see http://www.avo.alaska.edu/color_codes.php for complete definitions of Aviation color codes and Volcano 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:
John Power, Scientist-in-Charge, USGS
jpower@usgs.gov (907) 786-7497

Jeff Freymueller, Coordinating Scientist, UAFGI
jeff.freymueller@gi.alaska.edu (907) 378-7556

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].
Contact AVO Privacy Accessibility Information Quality FOIA
URL: www.avo.alaska.edu/activity/avoreport.php
Page modified: May 16, 2014 09:40
Contact Information: AVO Web Team

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