AVO Weekly Update

The weekly update from AVO:

Friday, August 31, 2007 11:50 AM AKDT (1950 UTC)

PAVLOF VOLCANO (CAVW#1102-03-)
55°24′57″ N161°53′24″ W, Summit Elevation 8261 ft (2518 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: Watch

The eruption of Pavlof Volcano that began August 15th continues. Seismicity has steadily increased over the past week and is characterized by volcanic tremor, frequent explosions, and debris flow signals. Satellite observations throughout the week show an intense thermal anomaly from lava fountaining, lava flow, and collapse of the lava flow front.

A continous volcanic ash and gas plume has been reported by ground observers, pilots, and in satellite images since August 28. The height of the eruption plume has varied but has generally been between 12,000 to 16,000 ft (3.7 to 4.9 km) above sea level (ASL). A more vigorous plume to 20,000 ft (6.1 km) ASL with associated lighting (indicative of volcanic ash) was reported by NWS observers in Cold Bay on August 30 at 21:30 ADT (05:30 UTC on August 31). In response, the National Weather Service issued an Ashfall Advisory and Marine Weather Statement. There were no reports of ash fall and the Advisory was cancelled at approximately 01:00 ADT August 31.

If activity continues to increase, larger ash clouds that could affect higher-flying aircraft may be produced. The most immediate ground hazard in the vicinity of the volcano includes light ash fall on nearby communities. Previous historical eruptions from Pavlof caused only a few millimeters (about 1/10th of an inch) of ash to fall on King Cove, Nelson Lagoon, Cold Bay, and Sand Point. Mudflows in drainages from the flanks of the volcano, and lava flows and avalanching of hot debris on the upper reaches of the volcano are also of concern in the uninhabited areas around the volcano. Satellite and seismic data and eyewitness observations suggest most of the surface lava activity is occurring on the southeast sector of the steep-sided volcano; this suggests that the Pacific Ocean side of the volcano is at most risk from avalanching hot debris.

At this time, we expect this eruption to follow the pattern of previous eruptions. The last eruption of Pavlof began in September 1996 and consisted of a several-month-long series of ash explosions, lava-fountaining, and lava-flow production. Ash clouds reached as high as 30,000 ft asl on one occasion. However, most ash clouds were below 20,000 ft asl. Prior to 1996, Pavlof erupted in 1986 sending ash as high as 49,000 ft asl on at least one occasion. A hazard assessment for Pavlof and the Emmons Lake volcanic center is available on the web at http://www.avo.alaska.edu/pdfs/SIR2006-5248.pdf

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″ N169°56′42″ W, Summit Elevation 5676 ft (1730 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: Watch

Periodically throughout the week satellite views showed a persistent thermal anomaly at Cleveland’s summit. Web camera views were cloudy all week.

AVO continues to monitor the volcano closely with satellite imagery as weather allows. The lack of a real-time seismic network at Cleveland means that AVO is unable to track local earthquake activity related to volcanic unrest. Short-lived explosions of ash that could exceed 20,000 ft above sea level can occur without warning and may go undetected on satellite imagery.

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 October 2006.

KOROVIN VOLCANO (ATKA ISLAND) (CAVW#1101-16)
52°22′48″ N174°9′22″ W, Summit Elevation 5030 ft (1533 m)
Current Aviation Color Code: YELLOW
Current Volcano Alert Level: Advisory

Intermittent, low-level seismic activity continued at Korovin. Satellite views were cloudy all week.

Korovin has erupted several times in the past 200 years, most recently in 1998. Eruptions typically produce minor amounts of ash and occasional, small lava flows. Ash plume heights could exceed 20,000 ft above sea level. Korovin occasionally produces large steam plumes from its summit.

Mount St. Helens Daily Update for 8/31/07

Current Mount St. Helens status from CVO:

Friday, August 31, 2007 09:25 PDT (Friday, August 31, 2007 16:25 UTC)

MOUNT ST. HELENS UPDATE
Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE: Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. During such eruptions, changes in the level of activity can occur over days to months. The eruption could intensify suddenly or with little warning and produce explosions that cause hazardous conditions within several miles of the crater and farther downwind. Small lahars could suddenly descend the Toutle River if triggered by heavy rain or by interaction of hot rocks with snow and ice. These lahars pose a negligible hazard below the Sediment Retention Structure (SRS) but could pose a hazard along the river channel upstream.

Potential ash hazards: Wind forecasts from the National Oceanic and Atmospheric Administration (NOAA), coupled with eruption models, show that any ash clouds rising above the crater rim today would drift northeast.

Potential ash hazards to aviation: Under current eruptive conditions, small, short-lived explosions may produce ash clouds that exceed 30,000 feet in altitude. Ash from such events can travel 100 miles or more downwind.

Recent observations: Under partly sunny skies, a steam plume can be seen rising from the new dome and drifting northeastward above the crater rim this morning. There are no significant changes in the on-going eruptive condition. Very low-level seismicity punctuated by sporadic rock falls are indicative of continued lava dome growth.

Yellowstone Monthly Update for August

The current monthly update for Yellowstone from YVO:

Wednesday, August 1, 2007 10:37 MDT
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

During the month of July 2007, 80 earthquakes were located in the Yellowstone Region. The largest of these shocks was a magnitude 2.2 on July 26, 2007 at 9:52 AM MDT, located about 9 miles north northwest of West Yellowstone, Montana. No swarms occured durring this period.

Earthquake activity in the Yellowstone region is at relatively low background levels.

Ground Deformation Summary: Through July 2007, continuous GPS data show that most of the Yellowstone caldera continued moving upward at similar to slightly lower rates as the past year. The maximum measured ground uplift over the past 34 months is ~15 cm at the White Lake GPS station. An example can be found at: [here]

The general uplift of the Yellowstone caldera is scientifically interesting and will continue to be monitored closely by YVO staff.

An article on another recent uplift episode at Yellowstone and discussion of long-term ground deformation at Yellowstone and elsewhere can be found at: http://volcanoes.usgs.gov/yvo/2006/uplift.html

Colima Daily Update for 8/31/07

Current Colima status from UCOL, translated via Google:

It sights on, Col., to 31 of August of 2007.
Report of the recent volcanic activity
(It reports: 12:00 hours)

The Government of the State, through the State Unit of Civil defense Sights on, informed that the volcanic cone has not presented/displayed seismic activity in last the twenty-four hours and, on the other hand, the cloudiness has prevented the visibility of exhalations or fumarolas; also, it indicated that reports on damages or affectation in the adjacent populations are not had.

In the occasion of the rain storm, aside from the storm clouds, light rains and sporadic electrical storms in the top of the volcano are reported, which forces to remember to the population that avoids the permanence in bordering ravines, before the possibility that they register lahares (mud flows).

On the other hand, it continues the restriction for the sobreflights that do not have scientific aims or of civil defense, and is prohibited the permanence of people other people’s to these activities in ravines of the volcano.

In permanent coordination with the State Unit of Civil defense Jalisco, the Government of the State of Sights on is pending of monitorear the activity of the volcano in real time; this way, he counts himself on opportune information to be able to respond before any contingency and to guarantee the security of the population, as it is the interest of the governor Jesus Silverio Cavazos Ceballos.

In addition, one works in the preventive programs to maintain informed to the citizens on the evolution into the volcanic activity, and to avoid that alarm by rumors is generated.

Also constant communication with the communitarian brigade that has formed with inhabitants of the town of the Becerrera, to those who exists has become qualified in the self-protection with respect to the natural disasters. Also, permanent contact with the personnel of the military team of Marijuana, the Becerrera stays, farm the Wild boar, as well as with elements of public security of the State, Comala and Civil defense of Cuauhtémoc.

They have been continuing the same recommendations established for months, in which it is indicated that who are or live in zone of risk, follow the indications that this organism transmits through mass media; it is necessary to emphasize that the zone of exclusion of activities for the states of Jalisco and Colima is of 7,5 kilometers from the top of the volcano on the channels of ravines. The radius of preventive alert remains in 11.5 kilometers from the top of the volcano, which includes the populations of Marijuana, and the Becerrera in the state of Sights on, and Causentla, Brotherhood of Tonila, Atenguillo, the Saucillo, the Fresnal, the Funnel, Juan Barragán, the Males, the Summer pasture and the Borbollón in Jalisco.

The permanence in ravines must be avoided the Fire, the Cordobán, San Antonio and Monte Grande, in It sights on, and the Dead, the Tuna, Santa Ana, the Cafecito, the Sand and Beltrán-Peach tree in Jalisco.

* Note: You can daily consult the information of the volcanic activity in the following electronic direction http://www.colima-estado.gob.mx/2006/seguridad/indvolcan.php

It sights on, Col 31 of August of 2007

Soufrière Hills Daily and Weekly Update

The currnet Soufrière Hills status from MVO:

The alert level remains at 4.

Measurable activity has remained low with no significant change over the last 24 hours.

The current weekly update for Soufrière Hills:

Summary report for the period midday 24 August to midday 31 August 2007

Activity during the reporting period of the Soufrière Hills Volcano (SHV) was low. The dome was visible occasionally on 25 and 26 August and no changes were noted in its morphology with the pause of lava extrusion continuing.

Recorded seismic activity remained very low throughout the period. The seismic network recorded just 17 rockfalls, 13 volcano-tectonic earthquakes and one (1) long period event.

The sulphur dioxide (SO2) flux rate ranged from a maximum of 1447 tonnes per day (t/d) to a minimum of 319 t/d during the reporting period. The average flux rate for the period stood at 740 t/d which is higher than the long-term average which remains around 550 t/d. Fourier Transform Infrared (FTIR) measurements of hydrogen chloride to sulphur dioxide ratios were possible on two days during the reporting period, they were 0.41 on 27 August and 0.39 on 28 August.

Baseline calculations between GPS stations were not possible due to lack of access to South Soufrière Hill.

The alert level remained at 4.

Residents of Montserrat and visitors to the island are advised to tune into ZJB Radio 88.3 or 95.5 FM for up-to-date information on the volcano.

Access to all areas on the lower flanks of the Belham Valley and further south, and south of Jack Boy Hill to Bramble airport and beyond is prohibited at all times (readers are refereed to the updated risk map). The maritime exclusion zone around the southern part of the island extends 4 km off shore from Spanish Point to Roches Yard on the east side of the volcano, 2 km offshore from O’Garras to Sturge Park on the south-west, and 2 km offshore from Isles Bay to Old Road Bluff on the west (maritime risk map).

For further explanations of the volcanic phenomena described, and information about the Soufrière Hills Volcano and the ongoing eruption, please look at the rest of the MVO website.

Popocatepet Daily Update for 8/31/07

Current Popocatepet status from CENAPRED:

August 31 11:10 h (16:10 GMT)

In the last 24 hours the monitoring system of Popocatepetl volcano registered only 3 exhalations accompanied by steam and gas emissions. The other monitoring parameters remain without important changes.

At this moment there is no visibility towards the volcano due to dense clouds. However, this morning we could observe it with a steam and gas emission (see image).

A vertical photo of the crater, obtained by the Dirección General de Carreteras Federales (SCT) on March 6, shows that the dimensions of the lava dome inside the crater do not have a significative change in comparison with those observed on January 24, 2007. This condition does not imply significant change in the expected scenarios(see image).

From high to low probability the expected activity scenarios in the next hours, days or weeks are: moderate exhalations, some with ash emissions; occasionally mild incandescence during nights and sporadic low level explosions with low probabilities of incandescent fragment at short distance to the crater.

There is a permanent monitoring of the volcano to detect any change. The traffic light of volcanic alert remains in YELLOW Phase 2.

Recommendations:
1. Access is restricted in a radius of 12 km from the crater. For this reason the permanence in this area is not allowed.
2. The road between Santiago Xalitzintla (Puebla) and San Pedro Nexapa (Mexico State), including Paso de Cortes, is open only to controlled traffic.
3. To the authorities of Civil Protection, maintain preventive procedures, according to operative plans.
4. To the population, to be aware of the official information emited.

Stromboli Daily Update for 8/31/07

Current Stromboli status from INGV, translated via Google:

Official notice of 31-8-2007
Modernization to the hours 12,00 premises
(the hour ones specify to you in the text are all GMT)

In the day odierna on the Island of Stromboli 4 units of staff INGV are present who four fields of monitoring operate within: Volcanology, Sismologia, Geochemistry and Deformations.

Official notice of the 29/08/2007: The images of the infrared television camera mail on the Peak over Fossa, in last the 24 hours, sufficient visibility of the craterica area has shown one.
The observed activity has been following:
- in the northern part of the craterica area two mouths have emitted gas launch in pressure it accompanies from ash and/or incandescent material to you with a frequency of 4-5/h that sometimes they have caught up the maximum height of 100 m while from the mouth it mails in the southern part they have been observed material outbreaks fine (ash) frammisto to rough material (lapilli and bombs) with a medium frequency of 1-2/h that 200 m of height have exceeded i.
The thermal television camera of 190 quota s.l.m and the visible one of quota 400, in last the 24 hours, do not have shown changes meant to you regarding the previous day neither of the area they of the Sciara centers of the Fire before, neither of northern the part sommita them of the volcano the second one.
From the visible television camera of quota 400, they have been observed the more energetic ash outbreaks and the activity of degassamento of the craterica area.

Pavlof Information Releases

AVO information release at 11:30 AKDT:

ALASKA VOLCANO OBSERVATORY

Information Release

Thursday, August 30, 2007 11:30 PM AKDT (730 UTC)

PAVLOF VOLCANO (CAVW#1102-03-)
55°24′57″ N161°53′24″ W, Summit Elevation 8261 ft (2518 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: Watch

At approximately 9:30 pm AKDT (0530 UTC August 31) National Weather Service observers in Cold Bay reported a substantial plume and associated lightning emanating from Pavlof Volcano up to 20,000 ft (6,000 m) above sea level. The plume was also visible in images from the Pavlof web camera located in Cold Bay. Although no ash is visible in satellite data, the occurrence of lightning increases the likelihood of ash in the plume. Airborne ash dispersion models indicate the possibility of light ash fall in the region of Sand Point.

If activity continues to increase in intensity, larger ash clouds that could affect higher-flying aircraft may be produced. The most immediate ground hazard in the vicinity of the volcano includes light ash fall on nearby communities. Previous historical eruptions from Pavlof caused only a few millimeters (about 1/10th of an inch) of ash to fall on King Cove, Nelson Lagoon, Cold Bay, and Sand Point. Mudflows in drainages from the flanks of the volcano, and lava flows and avalanching of hot debris on the upper reaches of the volcano are also of concern in the uninhabited areas around the volcano. Satellite and seismic data and eyewitness observations suggest most of the surface lava activity is occurring on the southeast sector of the steep-sided volcano; this suggests that the Pacific Ocean side of the volcano is at most risk from avalanching hot debris.

At this time, we expect this eruption to follow the pattern of previous eruptions. The last eruption of Pavlof began in September 1996 and consisted of a several-month-long series of ash explosions, lava-fountaining, and lava-flow production. Ash clouds reached as high as 30,000 ft ASL on one occasion. However, most ash clouds were below 20,000 ft ASL. Prior to 1996, Pavlof erupted in 1986 sending ash as high as 49,000 ft ASL on at least one occasion. A hazard assessment for Pavlof and the Emmons Lake volcanic center is available on the web at http://www.avo.alaska.edu/pdfs/SIR2006-5248.pdf

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 volcanoes 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.

AVO update from 1:20 A.M.:

ALASKA VOLCANO OBSERVATORY

Information Release

Friday, August 31, 2007 1:15 AM AKDT (915 UTC)

PAVLOF VOLCANO (CAVW#1102-03-)
55°24′57″ N161°53′24″ W, Summit Elevation 8261 ft (2518 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: Watch

There have been no indications in satellite data or ground reports of an ash plume resulting from the event that was observed at 9:30 pm AKDT yesterday (0530 UTC August 31). The National Weather Service ashfall advisory for the Sand Point area is no longer in affect.

Seismic activity remains elevated. If activity continues to increases in intensity, larger ash clouds that could affect higher-flying aircraft may be produced. The most immediate ground hazard in the vicinity of the volcano includes light ash fall on nearby communities. Previous historical eruptions from Pavlof caused only a few millimeters (about 1/10th of an inch) of ash to fall on King Cove, Nelson Lagoon, Cold Bay, and Sand Point. Mudflows in drainages from the flanks of the volcano, and lava flows and avalanching of hot debris on the upper reaches of the volcano are also of concern in the uninhabited areas around the volcano. Satellite and seismic data and eyewitness observations suggest most of the surface lava activity is occurring on the southeast sector of the steep-sided volcano; this suggests that the Pacific Ocean side of the volcano is at most risk from avalanching hot debris.

Long Valley Daily Update for 8/30/07

Current Long Valley status from LVO:

Long Valley Daily Update issued Aug 30, 2007 14:28 PDT Volcanic-Alert Level NORMAL – Aviation Color Code GREEN
The realtime computer system located five small earthquakes in the vicinity of Long Valley caldera since the last update on August 29. The events (all magnitude M<2.0) were located in the Sierra Nevada south of the caldera.

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