ALASKA VOLCANO OBSERVATORY
 WEEKLY UPDATE
 Friday October 8, 2004 4:00 PM ADT (00:0 0 UTC)
 
 ALASKA VOLCANOES
 
 MOUNT SPURR VOLCANO (CAVW#1103-04)
 61°18' N  152°15' W, Summit Elevation 11,070 ft (3,374 m)
 Current Level of Concern Color Code: YELLOW
 
 Elevated levels of seismicity continue to be recorded at Mt. Spurr volcano.
 This week, about 57 earthquakes were located within 30 km of the summit,
 with an average of approximately 8 events per day. No observation flights
 were conducted this week.  No anomalous activity was observed in satellite
 data, although clouds obscurred the view for most of the week.  The Spurr
 web cam is now available for viewing on the AVO website at:
 
 http://www.avo.alaska.edu/avo4/atlas/volc/spurr/spurr2004/index.html
 
 Mt. Spurr volcano is an ice- and snow-covered stratovolcano located on the
 west side of Cook Inlet. The only known historical eruptions occurred in
 1953 and 1992 from the Crater Peak flank vent located 3.5 km (2 mi) south
 of the summit of Mt. Spurr. These eruptions were explosive, brief in
 duration, and produced towering columns of ash that rose up to 20 km
 (65,000 ft) above sea level and deposited several mm of ash on populated
 areas of south-central Alaska, including approximately 6 mm of ash on
 Anchorage in 1953. The summit of Mt. Spurr and the surrounding avalanche
 caldera is heavily mantled by ice and snow. The last known eruption from
 the summit dome of Mt. Spurr was more than 5,000 years ago. The primary
 hazards associated with future eruptions from the Mt. Spurr summit vent and
 from Crater Peak include far-traveled ash clouds, ash fall, pyroclastic
 flows, and lahars or mudflows that could inundate drainages all sides of
 the volcano, but primarily on the south and east flanks.
 
 MOUNT VENIAMINOF VOLCANO (CAVW #1102-07)
 56°10'N 159°23'W, Summit Cone Elevation 7,073 ft (2,156 m)
 Current Level of Concern Color Code: YELLOW
 
 Low-level seismic tremor and intermittent small tremor bursts continue at
 Mount Veniaminof Volcano.  These tremor episodes likely represent low-level
 ash and steam emissions similar to those observed over the past four
 months, although cloudy conditions obscured views of the volcano in web
 camera and satellite data. Activity at Veniaminof could, at any time,
 become more vigorous, and the steam and ash emissions from the intracaldera
 cone do pose a hazard to people and low-flying aircraft in the vicinity of
 the caldera. AVO will continue to monitor activity at Veniaminof using
 seismic data, satellite images, Internet camera data and observer reports.
 
 Mount Veniaminof volcano is a young stratovolcano with an ice-filled 10-km
 (6 mi) 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 and most active volcanic centers in the
 Aleutian Arc and has erupted at least 12 times in the past 200 years. The
 most recent significant eruption of the volcano occurred in 1993-95 and was
 characterized by intermittent, low-level emissions of steam and ash, and a
 small lava flow onto the summit caldera ice field producing an ice pit.
 Previous historical eruptions have produced ash plumes that reached 6,000 m
 (20,000 ft) above sea level and associated ash fall within about 40 km (25
 mi) of the volcano. Minor ash emissions similar to those occurring at
 present were also detected in late 2002.
 
 
 
 SHISHALDIN VOLCANO (CAVW #1101-36)
 54°45'N 163°58'W, Summit Cone Elevation 9,373 ft (2,857 m)
 Current Level of Concern Color Code: YELLOW
 
 Low-level seismic tremor continues to be recorded at Shishaldin Volcano.
 This level of activity is similar to that observed over the past several
 months. Satellite views of the volcano this week were obscured by clouds.
 We see nothing at this time to indicate that more vigorous activity is
 imminent. However, activity at Shishaldin could increase rapidly and ash
 and gas emissions may pose a hazard to people and low-flying aircraft in
 the vicinity of the summit. AVO will continue to monitor activity at
 Shishaldin Volcano using seismic data, satellite images, and observer
 reports.
 
 Shishaldin Volcano, located near the center of Unimak Island in the eastern
 Aleutian Islands, is a spectacular symmetric cone with base diameter of
 approximately 10 miles (16 km). A small summit crater typically emits a
 noticeable steam plume with occasional small amounts of ash. Shishaldin is
 one of the most active volcanoes in the Aleutian volcanic arc, erupting at
 least 28 times since 1775. Most of Shishaldin's eruptions have consisted of
 small ash and steam plumes, although the most recent eruption in April-May
 1999 produced an ash column that reached a height of 45,000 ft above sea
 level.
 
 OTHER ALASKA VOLCANOES
 
 Seismic activity is monitored in real time at 27 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, Redoubt, Iliamna, Augustine, Snowy, Griggs, Katmai, Novarupta
 Trident, Mageik, Martin, Aniakchak, Pavlof, Dutton, Isanotski, Fisher,
 Westdahl, Akutan, Makushin, Okmok, 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.
 
 ABBREVIATED COLOR CODE KEY (contact AVO for complete description):
 GREEN volcano is dormant; normal seismicity and fumarolic activity
 occurring
 YELLOW volcano is restless; eruption may occur
 ORANGE volcano is in eruption or eruption may occur at any time
 RED significant eruption is occurring or explosive eruption expected at any
 time
 
 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-GI
 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.
 `
 
 

Hawaiian Volcanoes — Update from the Hawaiian Volcano Observatory

Kilauea Volcano — for more information, see Kilauea Update

Mauna Loa Volcano — for more information, see Mauna Loa Current Activity

Long Valley area — Update from the Long Valley Observatory

Cascade Range Volcanoes — Update from the Cascades Volcano Observatory

Volcanoes in the Cascade Range are all at normal levels of background seismicity except for Mount St. Helens. See Mount St. Helens update below.

Other volcanoes include Mount Baker, Glacier Peak, Mount Rainier, and Mount Adams in Washington State; Mount Hood, Mount Jefferson, Three Sisters, Newberry, and Crater Lake, in Oregon; and Medicine Lake, Mount Shasta, and Lassen Peak in northern California.

USGS Cascades Volcano Observatory, the Pacific Northwest Seismograph Network at the University of Washington, and the USGS Northern California Seismic Network and Volcano Hazards Team in Menlo Park, California, monitor the major volcanoes in the Cascade Range of northern California, Oregon, and Washington.

Mount St. Helens Update, October 14, 2004, 6:15 p.m, PDT

Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE

Seismic activity remained at a low level today. Today’s visual observations and thermal imaging of the crater were focused on the intensely deforming and uplifting area on the south side of the 1980-86 lava dome and the new lobe of lava in the western part of that area. The area of both the uplift and the new lobe of lava have increased slightly since yesterday. Yesterday’s gas-sensing flight detected low levels of sulfur dioxide and hydrogen sulfide, but no carbon dioxide. Abundant steam continues to rise from the area of lava extrusion to the crater rim, from which it is being dispersed downwind. Measurements taken yesterday of flow-rate and temperature in streams draining the crater showed no significant change from late September values.

Other field work today included a gas-sensing flight (data not yet reduced), downloading GPS data, and servicing GPS stations.

Wind forecasts from the National Oceanic and Atmospheric Administration (NOAA), combined with eruption models, show that any ash clouds will drift south-southeastward this evening and southeastward tomorrow morning. Magma continues to be at a very shallow level and is extruding onto the surface and forming a new lobe of the lava dome. Small emissions of steam and ash are possible. Reflection onto steam clouds of incandescence or glow from the hot rock and gases will be visible at night from some locations.

Lava-dome growth is a dynamic process and, as we observed in the mid-1980s, Mount St. Helens and similar volcanoes elsewhere typically go through episodic changes in level of activity over periods of days to weeks, or even months. We expect fluctuations in the level of eruptive activity to continue. Escalation could occur suddenly. Therefore, we continue to monitor the situation closely and will issue additional updates and changes in alert level as warranted.

Under current conditions, small lahars (volcanic debris flows) could be triggered if hot material from the new lava extrusion swiftly melts glacier ice. Such lahars pose negligible hazard below the Sediment Retention Structure (SRS), but could pose a hazard to people working or recreating along the river channel upstream of the SRS. Furthermore, due to weather and stream-flow conditions at this time of year, it is not unusual for rivers draining the volcano to contain high concentrations of sediment that turn the water murky.

There will no longer be daily media briefings at the Headquarters of the Gifford Pinchot National Forest. A media briefing will be held tomorrow at 1 p.m. at Castle Lake Viewpoint in the Mount St. Helens National Volcanic Monument. However no additional such briefing are planned until conditions warrant them. Beginning tomorrow, we will release only one daily update, at approximately 11 a.m. Tomorrow’s update will contain information regarding media contacts with the Joint Information Center.

Yellowstone area — Update from the Yellowstone Volcano Observatory

Yellowstone — for more information, see Yellowstone Monitoring Data

Commonwealth of the Northern Mariana Islands (See Anatahan home page)

Anatahan Volcano Update for October 9, 2004
Submitted Saturday, October 9, 2004 at 0700 local Anatahan time

There was no significant volcano-seismic activity in the Anatahan area during the past week.

On July 26, the seismicity level decreased dramatically to a very low level, and it remains very low. The seismic signals and visual reports indicate that the frequent strombolian explosions have ceased and suggest that the eruption is over.

Russia: Kamchatkan volcanoes — Update from the Kamchatkan Volcanic Eruption Response Team

Date: Fri, 15 Oct 2004 00:00:55 +0000

Kamchatkan and Northern Kurile Volcanic Activity
 INFORMATION RELEASE 50-04
 Friday, October 15, 2004, 12:40 KDT (23:40 UTC on October 14)
 
 The Alaska Volcano Observatory (AVO) received the following release via
 e-mail from KVERT (Kamchatkan Volcanic Eruptions Response Team). Kamchatkan
 Daylight saving Time (KDT) is 21 hours ahead of Alaska Daylight Savings
 Time. All time and dates are UTC, if not marked specifically.
 
 SUMMARY OF LEVEL OF CONCERN COLOR CODES:
 
 KAMCHATKA:
 SHEVELUCH and KARYMSKY: ORANGE
 KLYUCHEVSKOY and BEZYMIANNY: YELLOW
 TOLBACHIK PLOSKY, KIZIMEN, AVACHINSKY, KORYAKSKY, MUTNOVSKY and GORELY:
 GREEN
 
 NORTHERN KURILE: ALAID: GREEN
 
 SHEVELUCH VOLCANO: 56  38'N, 161  19'E; Elevation 3,283 m, the dome
 elevation ~2,500 m.
 CURRENT LEVEL OF CONCERN COLOR CODE IS ORANGE.
 Unrest at the volcano continues. A lava dome is growing in the active
 crater. At any time and with little warning, explosions could produce ash
 plumes that could rise as high as 10 km or 33,000 ft. ASL, as well as
 localized ash fall.
 
 Seismic activity was above background levels. Weak shallow earthquakes at a
 depth 0-5 km beneath the active dome were registered. Two strong shallow
 earthquakes of Ml=1.75 and 2.1 were recorded on October 08 and 11,
 respectively. Intermittent spasmodic volcanic tremor 0.4-0.5x10-6 mps was
 registered on October 07-12, and tremor increased to 0.7x10-6 mps on
 October 13. According to seismic data, possible weak ash-gas explosions and
 hot avalanches occurred all week. According to visual observations from
 Klyuchi, ash plumes rose up to 3.5 km (or 11,500 ft) ASL on October 07 and
 12, extended >10 km (or 6 mi) to the east. Weak gas-steam activity occurred
 on October 11 and 12. Clouds obscured the volcano at other times. According
 to satellite data from the USA and Russia, 1-7-pixel thermal anomaly was
 registered over the lava dome all week. A narrow ash plume extending 31 km
 (or 19 mi) to the east-southeast was observed on October 08. A dust-ash
 cloud extending ~ 400 km (or 250 mi) to the south-east was noted on October
 10-11. The possible reason of this phenomenon was very strong wind (more
 than 20 mps) in the volcano area. There was no seismic data about any ash
 explosions that time. An ash plume extending up to the 300 km (or 186 mi)
 to the southeast was observed on October 12.
 
 KARYMSKY VOLCANO: 54  03'N, 159  27'E; Elevation 1,486 m.
 CURRENT LEVEL OF CONCERN COLOR CODE IS ORANGE.
 Over the past three weeks the number of seismic events at the volcano has
 increased. Accordingly, the danger of a sudden explosion or series of
 explosions up to 6 km (or 19,800 ft.) ASL is high. A local ash fall within
 a few tens of km around the volcano is also possible.
 
 Seismic activity was above background levels this week. The number of local
 shallow events was 310-540 events per day. According to seismic data,
 possible weak ash-gas explosions took place all week. Possible ash-gas
 explosions up to 2.5-3 km (or 8,200-9,800 ft) ASL occurred on October 09,
 12, 13. According to satellite data from the USA and Russia, 2-5-pixel
 thermal anomaly over the volcano was noted on October 08, 09, 11 and 12.
 Ash plumes, extending 80 and 50 km (or 50 and 35 mi) to the east then
 east-southeast were noted on October 11 and 12, respectively. Clouds
 obscured the volcano at other times.
 
 KLYUCHEVSKOY VOLCANO: 56  03'N, 160  39'E; Elevation 4,750 m
 CURRENT LEVEL OF CONCERN COLOR CODE IS YELLOW.
 Seismic activity of the volcano is increasing a little. Fumarolic activity
 of the volcano is recorded every day. Occasional and repeated explosions,
 containing ash and reaching altitudes of 5-6 km (or 16,500-19,800 ft), are
 possible at any time.
 
 Seismic activity was at background levels this week. 654 earthquakes of
 Ml=1.2- 2.3 and 132 strong ones of Ml>1.7 at a depth ~ 30 km beneath the
 volcano were recorded on October 07-13. Numbers of strong earthquakes
 suddenly increased to 53 on October 10. According to visual observations
 from Klyuchi, a gas-steam plume rose up to 5 km (or 16,400 ft) ASL
 extending to the east-southeast was noted on October 08. Weak fumarolic
 activity occurred on October 08-10. Clouds obscured the volcano at other
 times.
 
 
 BEZYMIANNY VOLCANO 55  58'N, 160 36'E; Elevation 2,895 m
 CURRENT LEVEL OF CONCERN COLOR CODE IS YELLOW.
 Unrest at the volcano continues. The lava dome of the volcano is growing.
 Fumarolic activity of the volcano is recorded every day. The thermal
 anomaly over the lava dome is noted sometimes. The nearest (13.5 km)
 seismic station from the volcano is located at Klyuchevskoy volcano slope.
 The registration of weak shallow seismic events is difficult.
 
 Seismic activity was not exceeding background levels at all week. According
 to visual observations from Klyuchi, on October 07, 11 and 12, gas-steam
 plumes rose up to 3 km (or 9,800 ft) ASL and extended to the north-west up
 to the 10 km (or 6 mi) on October 07. Clouds obscured the volcano at other
 times. According to satellite data from the USA and Russia, 1-2-pixel
 thermal anomaly over the dome was noted on October 10 and 12.
 
 PLEASE CONTACT AVO IF YOU HAVE QUESTIONS OR COMMENTS
 
 Sergey Ushakov
 Kamchatkan Volcanic Eruptions Response Team
 IVS FED RAS, Piip Blvd, 9
 Petropavlovsk-Kamchatsky, 683006 RUSSIA
 E-mail: ushakov@kcs.iks.ru
 Tel. (41522) 58627
 
 Tom Murray
 Scientist-in-Charge, Alaska Volcano Observatory
 4200 University Drive
 Anchorage, Alaska 99508 USA
 E-mail: tlmurray@usgs.gov
 Tel. 907-786-7497
 
 The Kamchatkan Volcanic Eruption Response Team is a cooperative program of
 the Alaska Volcano Observatory (USA), the Institute of Volcanology and
 Seismology FED RAS and the Kamchatkan Experimental and Methodical
 Seismological Department GS RAS (Russia).