Volcano update December 8, see pg 33

:kasat1:
picture of Kasatochi Volcano and lake Alaska in 2004

:kasat2:
elevation drawing of Kasatochi prior to the recent eruption

Mayon being watched
[link to eruptions.wordpress.com]
August 10, 2008 by Erik Klemetti
:mayon1:
[link to www.pbase.com]
December 13, 2006
copyright Tomas Tam


:mayon2:
Mayon, a volcano in the Philippines, is on watch for an eruption after experiencing small explosions. Philvolcs, (short for the Philippine Institute of Volcanology and Seismology), reports a small ash emission - ~200 feet - but they feel that there isn’t an imminent threat of an eruption. Mayon is an relatively active volcano in the Philippines, last erupting in 2006 and is well known for its prototypical conical volcano shape (see above).

Chaiten area airport north view, you can jsut see the plume through the V in the mountains on a few of the images where the skies clear jsut a little in that area.

[link to www.aipchile.cl]

The Chilean Geology dept (Sernageomin) released a report on the 4th that said basically over 3 days (from about Aug 2) there was slightly increased activity in the Chaiten area, with 15 VT (volcanic-tectonic) earthquakes, 4 of which were in the vicinity of the caldera. All the magnitudes appear to be minor to moderate (Mw4 seeming the highest). There was also minor emission vapors noted during this time. So, there does appear to be a slight increase in potential activity, but, at least it is now monitored.

:chaiten83:
shows the locations of the of the epicenters nearest the caldera.


See [link to www2.sernageomin.cl]
for more details. It's in Spanish, so be fore warned.

Kasatochi Volcano Activity Notifications
2008-08-09 22:04:18 - VAN/VONA
The intense seismic activity associated with the Kasatochi eruption has declined and is no longer detected on the AVO seismic network on nearby Great Sitkin Island (about 40 km (25 mi) to the east). Vigorous ash emissions (up to 35,000 feet) have not been observed in satellite data for about 36 hours and AVO has received no pilot reports of ash clouds. Passing mariners report nothing unusual and no obvious indications that an explosive eruption is in progress. It appears that explosive eruptive activity has waned and AVO is lowering the aviation color code and alert level to ORANGE/WATCH.

[link to www.oma.be]

gal look at the VERY high concentration of S02 approaching the west coast of the USA on this chart.

wait a bit longer and the chart should fill in too, making it even more dramatic.

I take it, you think this is from Kasatochi.

Alaska Volcano Observatory
Current Status Report
Sunday, August 10, 2008 2:12 PM AKDT (22:12 UTC)


KASATOCHI VOLCANO
52°10'9" N 175°30'41" W, Summit Elevation 1030 ft (314 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

The intense seismic activity associated with the Kasatochi eruption has declined but low level activity can be detected on the AVO seismic network on nearby Great Sitkin Island (about 40 km (25 mi) to the east). Vigorous ash emissions (up to 35,000 feet) have not been observed in satellite data for over two days and AVO has received no pilot reports of ash clouds.





Because Kasatochi lacks a seismic network, it may be difficult to determine if or when ash emissions may resume and the volcano remains in a hazardous state. It is possible for explosive activity to resume with little or no warning.

OKMOK VOLCANO
53°23'49" N 168°9'58" W, Summit Elevation 3520 ft (1073 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Eruptive activity continues at Okmok Volcano on Umnak Island in the eastern Aleutian Islands. The intensity of activity has been variable over the past day, showing both steady and at times elevated seismicity. A low-level steam plume is seen in satellite data extending towards the southeast at an estimated altitude of less than 20,000 feet asl. Periods of intense seismicity are not necessarily corresponding with episodes of significant ash production and this has complicated attempts to provide early warning about potential ash cloud hazards based on seismicity alone.




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

Volcanic unrest at Cleveland Volcano continues, with a thermal anomaly observed in satellite images over the past 48 hours, and is likely the result of the cooling of the newly emplaced lava flows. No ash plumes have been observed in satellite images since July 29. AVO has received no new information about activity at Cleveland Volcano for several days.
Rockfalls and avalanches of hot debris from the cooling lava flows on the flanks of Cleveland can occur with little or no warning. These events can produce small, localized ash plumes and block and ash flows or avalanches that are hazardous to anything in their path.


VOLCANO INFORMATION ON THE INTERNET: [link to www.avo.alaska.edu]

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

CONTACT INFORMATION:
Chris Waythomas, Acting Scientist-in-Charge, USGS
[email protected], (907)786-7497

Jon Dehn, Acting Coordinating Scientist, UAFGI
[email protected] (907) 474-6499

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.

Mayon Volcano under tight watch after mild explosion
By Ephraim Aguilar
Southern Luzon Bureau
First Posted 17:16:00 08/10/2008
LEGAZPI CITY, Philippines--The Philippine Institute of Volcanology and Seismology is keeping a tight watch over Mayon volcano after it monitored a mild explosion in the mountain at 9:12 a.m. Sunday, a Phivolcs bulletin at noontime said.

Mt. Mayon emitted smoke that reached a height of around 200 meters above the summit, said the Phivolcs bulletin. The smoke from the volcano summit later drifted east northeast.

"The volcano is undergoing an episode of increased activity probably related to magma movement and though no major eruption is indicated, steam and ash explosions may occur in the following days," added the bulletin.

The Phivolcs reiterated that Alert Level 1 remained over Mt. Mayon as of Sunday. It has also reminded the public that the seven-kilometer extended danger zone at the southeastern flank and the six-kilometer permanent danger zone at other areas remain off-limits due to threats from sudden small explosions and rockfalls from the upper slopes.
[link to newsinfo.inquirer.net]

Except the Philvolcs doesn't have any new info on it's site yet... hrmmm. maybe no one in yet to update their web site?
[link to www.phivolcs.dost.gov.ph]

August 10th, 2008
Robot submarine to dive deep in the Caribbean
Posted by Roland Piquepaille @ 9:13 am

According to BBC News, a new UK autonomous underwater vehicle (AUV), Autosub6000, will soon start to explore the world’s deepest undersea volcanoes located in the Caribbean.

Autosub6000 has a range of up to 1,000 kilometers and has a maximum operating depth of 6,000 meters. It is 5.5 meters long, has a diameter of 0.9 meter, and is equipped with a high-performance GPS unit. For these two expeditions, each close to a month long, Autosub6000 will be joined by the Isis remotely operated vehicle (ROV) which is able to operate at a depth of 6,000 meters and grab animal specimens. Researchers from the National Oceanography Center in Southampton (NOCS) will lead these missions. And they expect that ‘one in every two animals they come across will be a species new to science’ once the robots reach a depth of 3,000 meters.

Fascinating, but read more and some GREAT picts at link…
[link to blogs.zdnet.com]

The Caribbean volcanoes are known to be some of the deepest in the world, at about 6,000 meters at the bottom of Cayman Trough, so this should be a great workout for the vehicle. it's aboard the RRS James Cook dedicated research vessel and plans 2 two month long trips to the Caribbean volcanoes. It will also be joined by the Isis remote sub. Nice place to be during Uks winters!

yes.

look at it now. very impressive stuff.

Curious. Do you consider yourself a geologist, volcanologist or meteorologist?

a bit like yourself MO

a cut and paste specialist.



Still, it's all interesting stuff, eh?

ok then. hrmm, high opinion of yourself, huh.

Kasatochi ash causing airline cancellations
[link to eruptions.wordpress.com]
August 11, 2008 by Erik Klemetti


The current eruption at Kasatochi is causing a lot of flight cancellations for flights from Alaska to points in the continental US. The ash is swirling its way around the Aleutians along flight lanes (see above), with the ash drifting southeast over the Alaska Panhandle and could hamper air travel in Alaska and Canada for days according to the USGS (although Alaska Air says it might start flying again later today). As for the eruption itself, not much new news beyond the initial impression that the volcano went from quiet to explosively erupting to produce at 35,000 foot (~10,000 meter) ash column in a short period of time. The little bit of information I can glean from these articles mentions that activity at Kasatochi appeared to increase over the weekend (and that seismic activity increased and decreased over the weekend at one of the other erupting Aleutian volcanoes, Okmok).

Update 8/11/08 12:30PM PDT: Alaska Air has resumed its flights from Alaska.

Alaska Volcano Observatory
Current Status Report
Monday, August 11, 2008 2:18 PM AKDT (22:18 UTC)


CLEVELAND VOLCANO
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Satellite data from the past several days indicate that Cleveland is still actively erupting lava at the summit. No ash plumes have been observed in satellite images since July 29 and AVO has received no new information about Cleveland today.
Rockfalls and avalanches of hot debris from the cooling lava flows on the flanks of Cleveland can occur with little or no warning. These events can produce small, localized ash plumes. Larger rockfalls can produce block and ash flows or avalanches that are hazardous to anything in their path.

Please see [link to www.avo.alaska.edu] for more information.

KASATOCHI VOLCANO
52°10'9" N 175°30'41" W, Summit Elevation 1030 ft (314 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Seismic activity at Kasatochi can be detected by the AVO seismic network on nearby Great Sitkin Island but is at a low level. No ash emissions have been observed in satellite data for over two days and AVO has received no pilot reports of ash clouds.

A volcanic cloud from the August 7 eruption has drifted over the North Pacific and is currently nearing the Alaska panhandle.

:kasat3:
Picture Date: August 10, 2008 UTC
Image Creator: Schneider, Dave
Image courtesy of AVO/USGS

Because Kasatochi lacks a seismic network, it may be difficult to determine if or when ash emissions may resume and the volcano remains in a hazardous state. It is possible for explosive activity to resume with little or no warning.


OKMOK VOLCANO
53°23'49" N 168°9'58" W, Summit Elevation 3520 ft (1073 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Eruptive activity continues at Okmok Volcano on Umnak Island in the eastern Aleutian Islands. The intensity of activity has been variable over the past day, showing both steady and at times elevated seismicity. No ash clouds have been observed in satellite data over the past 24 hours.

Minor ash fall may occur over parts of Umnak Island.

VOLCANO INFORMATION ON THE INTERNET: [link to www.avo.alaska.edu]

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

CONTACT INFORMATION:
Chris Waythomas, Acting Scientist-in-Charge, USGS
[email protected], (907)786-7497

Jon Dehn, Acting Coordinating Scientist, UAFGI
[email protected] (907) 474-6499

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 VOLCANO OBSERVATORY DAILY UPDATE
Monday, August 11, 2008 07:42 HST (Monday, August 11, 2008 17:42 UTC)


KILAUEA VOLCANO (CAVW#1302-01-)
19.42°N 155.29°W, Summit Elevation 4091 ft (1247 m)
Volcano Alert Level: WATCH
Aviation Color Code: ORANGE

This report on the status of Kilauea volcanic activity, in addition to maps, photos, and webcam images (available using the menu bar above), was prepared by the USGS Hawaiian Volcano Observatory (HVO). Hawai`i Volcanoes National Park status can be found at [link to www.nps.gov] or 985-6000. Hawai`i County Viewing Area status can be found at [link to www.lavainfo.us] or 961-8093.

Activity Summary for last 24 hours: Kilauea summit continued to produce small amounts of ash and elevated amounts of sulfur dioxide gas from the Halema`uma`u vent. At the east rift eruption site, Pu`u `O`o cone continued to produce elevated amounts of sulfur dioxide gas; the TEB eruption has resumed with lava flowing through tubes to the ocean and supplying several surface flows.

Last 24 hours at Kilauea summit: The Halema`uma`u vent pulsed with episodic incandescence overnight when not blocked by fog.

A white plume is rising from the Halema`uma`u vent this morning and being blown southwest 100-200 m (330-650 ft) above the Ka`u Desert. Sulfur dioxide emission rates remained elevated and variable; the most recent average measurement was 900 tonnes/day on August 7 compared to 700 tonnes/day on August 4 and a pre-2008 background rate between 150-200 tonnes/day.

Small amounts of ash continued to be collected from the plume this morning, although the strong winds are making their own contribution. Some rock impact sounds were also heard near the vent when the wind sounds died down enough.

The summit tiltmeter network recorded deflation. The network of GPS receivers that span the summit caldera recorded some inflation followed by no change through this morning.

Seismic tremor continued with episodic bursts every 5-7 minutes with several brief hiatuses. The number of RB2S2BL earthquakes beneath Halema`uma`u Crater declined but remained well above background values; this may be, in part, augmented by the episodic tremor bursts. Three earthquakes were located beneath the summit area, two on Koa`e faults, and one on south flank faults.

Last 24 hours at the middle east rift zone vents and flow field: Magma continued to degas through Pu`u `O`o Crater resulting in an emission of 2,400 tonnes/day of sulfur dioxide on August 8, down from a high of 7,100 tonnes/day on July 18 and near background values of about 2,000 tonnes/day. No incandescence was observed within the crater last night.

The tiltmeter on the north side of Pu`u `O`o cone recorded deflation. GPS receivers continued to record possible weak extension. Seismic tremor levels peaked overnight and are currently decreasing to background levels near Pu`u `O`o but remain elevated near the TEB vent.

Lava resumed flowing through the TEB vent and the rootless shield field yesterday continuing through tubes to the ocean. HVO geologists observed a small lava flow advancing northward from the TEB vent, a dome fountain within a lava pond atop one of the rootless shields, a nearly stagnant surface flow at the top of the abandoned Royal Gardens subdivision, and four breakouts on the coastal plain (see photos and map). The Waikupanaha ocean entry steam plume resumed just after 9 am. The largest active breakout on the coastal plain issued two channelized surface flow, one of which entered the ocean to the west of Waikupanaha about 9:40 am.

[link to volcano.wr.usgs.gov]

NORTHERN MARIANA ISLANDS INFORMATION RELEASE
Tuesday, August 12, 2008 09:43 MPT (Monday, August 11, 2008 23:43 UTC)


ANATAHAN VOLCANO (CAVW#0804-20=)
16.35°N 145.67°E, Summit Elevation 2592 ft (790 m)
Volcano Alert Level: ADVISORY
Aviation Color Code: YELLOW

Report prepared by the U.S. Geological Survey.

The Aviation color code is being lowered from Orange to Yellow and the Alert level from Watch to Advisory at Anatahan volcano. Seismicity remains low. Photographs from a visit to the volcano Aug. 8 show a low-level (6,000-7,000 ft above sea level) relatively passive steam plume rising above the island. Occasional SO2 plumes have been seen over the past few weeks by satellite, but no ash has been identified.

During times of northerly winds, the Anatahan plume, if present, could be directed towards the CNMI and Guam. If this happens, residents may notice hazy air conditions and smell sulfur. The Emergency Management Office (EMO) of the CNMI government will issue volcanic haze and sulfur advisories if appropriate.

Access to the island may be restricted by the CNMI government. Contact the EMO to get the latest information.

USGS contact information: duty scientist (808) 967-8815 [link to volcano.wr.usgs.gov]

Alaska Volcano Observatory
Current Status Report
Tuesday, August 12, 2008 12:23 PM AKDT (20:23 UTC)


CLEVELAND VOLCANO
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Satellite data from this morning indicate that Cleveland volcano erupted a small ash plume to about 25,000 feet. As of about 11:00 AM AKDT the plume had drifted southwest about 60 miles (100 km) and appears to be dissipating. A pilot in the region reported no obvious ash emissions at the volcano at about 10:00 AM AKDT this morning.
Small ash bursts and low-level ash plumes may continue to be produced by Cleveland Volcano. It is also possible for larger, higher reaching plumes to be produced without warning.

KASATOCHI VOLCANO
52°10'9" N 175°30'41" W, Summit Elevation 1030 ft (314 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Seismic activity at Kasatochi is still being detected by the AVO seismic network on nearby Great Sitkin Island. No ash emissions have been observed in satellite data for several days and AVO has received no pilot reports of ash clouds.



A volcanic cloud from the August 7 eruption has drifted over the North Pacific and is currently caught by a gyre in the southeastern Gulf of Alaska. The ash plume is dissipating but still contains ash and gas.

Because Kasatochi lacks a seismic network, it may be difficult to determine if or when ash emissions may resume and the volcano remains in a hazardous state. It is possible for explosive activity to resume with little or no warning.

OKMOK VOLCANO
53°23'49" N 168°9'58" W, Summit Elevation 3520 ft (1073 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Eruptive activity continues at Okmok Volcano. The intensity of activity has been variable over the past day. No ash clouds have been observed in satellite data, but a pilot report this morning indicated an ash plume to 15,000 feet. An observer in Nikolski, west of the volcano, also reported seeing an ash plume above the volcano yesterday.



Minor ash fall may occur over parts of Umnak Island.

VOLCANO INFORMATION ON THE INTERNET: [link to www.avo.alaska.edu]

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

CONTACT INFORMATION:
Chris Waythomas, Acting Scientist-in-Charge, USGS
[email protected], (907)786-7497

Jon Dehn, Acting Coordinating Scientist, UAFGI
[email protected] (907) 474-6499

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.

Montserrat Volcano Observatory
Weekly Report for the period 1 – 8 August 2008

The Soufriere Hills Volcano has been relatively quiet following the event which occurred on Monday 28 July, with one or two small ash clouds and seismic activity at low levels. There has been a significant increase in the sulphur-dioxide flux.

A small ash cloud was observed at around 1 pm on Thursday 7 August. There are unconfirmed reports of a similar ash cloud between 3 and 4 pm on Sunday 3 August. There were no seismic signals associated with either of these.

Seismic activity was relatively low this week. The MVO recorded 16 rockfalls, 30 long period, 8 hybrid and 14 volcano-tectonic events. There were no swarms of seismic activity, with the events occurring throughout the week.

The average sulphur dioxide (SO2) flux for the week was 1121 tons per day (t/d) with a minimum of 671 t/d on August 5 and a maximum of 2069 t/d on August 3. These values are significantly higher than the values before the event on 28 July.

Further investigation of the event on Monday 28 July has confirmed that it was a vertical explosion, with a small amount of dome collapse. The total amount of material involved was probably around 200,000 – 300,000 cubic metres. Cloud cover has prevented any clear views of the dome since the event, but satellite radar images indicate that the vent above Gages Wall has been enlarged by the explosion and now has dimensions of about 150 by 60 metres, elongated east-west. Most of the ejected material would have come from this vent.

All indications are that the explosion on 28 July cleared a blockage from the Gages Wall vent. The increase in gas flux and the non-seismic generation of small ash clouds suggest that the vent is more open than before.

The satellite data also showed that the stability of the dome was not affected by the explosion. In consequence, the precautionary access restrictions for areas in and around the Belham Valley have been lifted.

A new Hazard Level System has been designed by the Montserrat Volcano Observatory and DMCA in consultation with the Government of Montserrat and community groups.

The Hazard Level System divides the southern two-thirds of Montserrat into six zones along with two Maritime Exclusion Zones. Access permission for each of these zones is dependent on the Hazard Level. The Hazard Level, which ranges from 1 to 5, is set by NDPRAC on the advice of the MVO.

The Hazard Level is not related to the Alert Level used before. Leaflets and posters explaining the system are available from DMCA, MVO and several other locations on Montserrat.

The new Hazard Level System takes immediate effect. The current Hazard Level is 3. Current access restrictions are unchanged.
[link to www.mvo.ms.]

WOOHOO!!! Finally! A Clear day in Chile!
Chaiten area airport north view, you can see the plume quite easily, now.

[link to www.aipchile.cl]

There haven't been any new updates from Sernageomin SInce the 4th. But, now with a few clear days, they may get to do a fly over, measure the dome, take any other measurements and post a new report.

In case anyone missed the plume and wants to see it, Olaf Kossner posted the clip from today on the web.
[link to s280.photobucket.com]
Very nice viewing!

Kasatochi eruption - satellite images 13 August 2008
Posted by volcanismblog
[link to volcanism.wordpress.com]

Kasatochi volcano in the Aleutian Islands erupted on 7 August: full information about this dramatic and powerful eruption can be found at the Alaska Volcano Observatory and via the coverage at Eruptions.

:kasat4:
[link to earthobservatory.nasa.gov]
:kasat5:
[link to earthobservatory.nasa.gov]
Satellite image from Aug 10, 2008

The images above come from the NASA Earth Observatory site. The upper image, from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, shows Kasatochi’s brown eruption plume swirling counterclockwise from the volcano on 8 August 2008. The lower image comes from the Ozone Monitoring Instrument on NASA’s Aura satellite and indicates the levels of sulphur dioxide released by the Kasatochi eruption. The image was captured on 10 August 2008. The NASA caption for this image notes that the Kastachi eruption cloud contained about 1.5 million tons (1.36 million tonnes) of sulphur dioxide, and is one of the largest volcanic SO2 clouds scientists have tracked since Chile’s Hudson volcano erupted in 1991.

Current satellite image from NASA of the plume and SO2 dispersion over Canada and back over alaska, the Pacific ocean and parts of the west coast and midwest mainland US, from today Aug 13, 2008
:kasat6:

[link to earthobservatory.nasa.gov]

"If you could compress all the sulfur dioxide in that column of the atmosphere into a flat layer at the Earth’s surface (at 0 degrees Celsius), one Dobson Unit of the gas would be 0.01 millimeters thick, and it would contain 0.0285 grams of sulfur dioxide per square meter."

New Activity/Unrest

ASAMA Honshu 36.403°N, 138.526°E; summit elev. 2568 m

Based on information from JMA, the Tokyo VAAC reported that on 10 and 11 August eruption plumes from Asama rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE and S, respectively.

Geologic Summary. Asama, Honshu's most active volcano, is located at the junction of the Izu-Marianas and NE Japan arcs and has an historical record dating back at least to the 11th century. The modern cone of Maekake-yama is situated E of the horseshoe-shaped remnant of an older andesitic volcano, Kurofu-yama, which was destroyed by a late-Pleistocene landslide about 20,000 years before present (BP). Growth of a dacitic and rhyolitic lava cone was accompanied by pumiceous pyroclastic flows, the largest of which occurred about 14,000-11,000 years BP, and by growth of the Ko-Asama-yama lava dome on the E flank. Maekake-yama is probably only a few thousand years old, but has had several major Plinian eruptions, the last two of which occurred in 1108 and 1783 AD.


BEZYMIANNY Central Kamchatka (Russia) 55.978°N, 160.587°E; summit elev. 2882 m

Based on observations of satellite imagery, KVERT reported that a thermal anomaly detected over Bezymianny's lava dome grew in area and intensified during 9-11 August. Based on interpretations of seismic data, four hot avalanches occurred on 10 August and nine occurred on 11 August. On 12 August, the level of Concern Color Code was raised to Orange.

Geologic Summary. Prior to its noted 1955-56 eruption, Bezymianny volcano had been considered extinct. Three periods of intensified activity have occurred during the past 3,000 years. The latest period, which was preceded by a 1,000-year quiescence, began with the dramatic 1955-56 eruption. That eruption, similar to the 1980 event at Mount St. Helens, produced a large horseshoe-shaped crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flows, has largely filled the 1956 crater.


KASATOCHI Andreanof Islands 52.177°N, 175.508°W; summit elev. 314 m

On 6 August, AVO raised the Volcano Alert Level for Kasatochi to Advisory and the Aviation Color Code to Yellow based on increased seismicity detected that day by instruments in the area and by field crews on the island the previous few days. Kasatochi lacks dedicated seismometers and is monitored by neighboring networks.

On 7 August, earthquake activity continued; events as large as M 5.6 were detected. Crews reported rockfalls, ground shaking lasting 5-10 minutes, and a strong sulfur smell. Periods of volcanic tremor prompted AVO to raise the Volcano Alert Level to Watch and the Aviation Color Code to Orange. Later that day, an ash plume at an altitude of at least 10.7 km (35,000 ft) a.s.l. was detected on satellite imagery drifting SSW. The Volcano Alert Level was raised to Warning and the Aviation Color Code was raised to Red. Reports from a marine vessel in the area indicated ashfall and tephra up to pebble size, spectacular lightning, and total darkness for a little over 2 hours. Three major explosive eruptions produced ash plumes that rose to an altitude of 13.7 km (45,000 ft) a.s.l.

Ash emissions became continuous on 8 August following the last explosive event; an ash plume drifted for more than 950 km in a counterclockwise spiral at altitudes of about 9.1-13.7 km (30,000-45,000 ft) a.s.l. Seismicity decreased, although remained elevated, and ash emissions became less frequent. During 8-9 August, seismicity decreased to a level undetectable by stations on Great Sitkin, about 40 km W. On 9 August ash plumes were detected on satellite imagery early in the day; clouds prevented views during the rest of the day. The Volcano Alert Level was lowered to Watch and the Aviation Color Code to Orange. The ash plume from the third eruption on 7 August was seen on satellite imagery 1,850 km ESE of the volcano and was elongated NE-SW over 1,200 km.

According to news articles, flights from Alaska to several west coast cities were cancelled on 10 and 11 August. During 10-12 August, AVO reported that seismicity remained low, but detectable by the network on Great Sitkin.

Geologic Summary. Located at the northern end of a shallow submarine ridge trending perpendicular to the Aleutian arc, Kasatochi is small 2.7 x 3.3 km wide island volcano with a dramatic 750-m-wide summit crater lake. The summit of Kasatochi reaches only 314 m above sea level, and the lake surface lies less than about 60 m above the sea. A lava dome is located on the NW flank at about 150 m elevation. The asymmetrical island is steeper on the northern side than the southern, and the volcano's crater lies north of the center of the island. Reports of activity from the heavily eroded Koniuji volcano to the east probably refer to eruptions from Kasatochi. A lava flow may have been emplaced during the first historical eruption in 1760.


KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4835 m

KVERT reported that seismic activity at Kliuchevskoi had slowly increased since June and was slightly above background levels during 1-8 August. Observations of satellite imagery revealed that the size and intensity of a thermal anomaly in the crater increased. On 8 August, the level of Concern Color Code was raised to Yellow.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 7,000 years ago, the beautifully symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. More than 100 flank eruptions, mostly on the NE and SE flanks of the conical volcano between 500 m and 3,600 m elevation, have occurred during the past 3,000 years. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included major explosive and effusive events from flank craters.


MAYON Luzon 13.257°N, 123.685°E; summit elev. 2462 m

On 10 August, a mild explosion from Mayon produced an ash plume to an altitude of 2.7 km (8,900 ft) a.s.l. and drifted ENE. PHIVOLCS reported that during the previous few weeks seismic activity had increased slightly and incandescence at the crater had intensified. The Alert Level remained at 1. The 7-km Extended Danger Zone (EDZ) on the SE flank and the 6-km Permanent Danger Zone (PDZ) in all other areas remained in effect.

Geologic Summary. Beautifully symmetrical Mayon volcano, which rises to 2,462 m above the Albay Gulf, is the Philippines' most active volcano. The structurally simple volcano has steep upper slopes that average 35-40° and is capped by a small summit crater. The historical eruptions of this basaltic-andesitic volcano date back to 1616 and range from Strombolian to basaltic Plinian. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic flows and mudflows have commonly swept down many of the approximately 40 ravines that radiate from the summit and have often devastated populated lowland areas. Mayon's most violent eruption, in 1814, killed more than 1,200 people and devastated several towns. Eruptions that began in February 2000 led PHIVOLCS to recommend on 23 February 2000 the evacuation of people within a radius of 7 km from the summit in the SE and within a 6 km radius for the rest of the volcano.


Ongoing Activity

ANATAHAN Mariana Islands (Central Pacific) 16.35°N, 145.67°E; summit elev. 790 m

During 7-8 August, small sulfur dioxide plumes from Anatahan were visible on satellite imagery. On 8 August, seismicity decreased significantly. During 8-9 August, steam plumes with small amounts of ash rose to an altitude of 1.8 km (6,000 ft) a.s.l. On 12 August, the Volcanic Alert Level was lowered to Advisory and the Aviation Color Code to Yellow.

Geologic Summary. The elongate, 9-km-long island of Anatahan in the central Mariana Islands consists of large stratovolcano with a 2.3 x 5 km, E-W-trending compound summit caldera. The larger western caldera is 2.3 x 3 km wide, and its western rim forms the island's 790-m high point. Ponded lava flows overlain by pyroclastic deposits fill the floor of the western caldera, whose SW side is cut by a fresh-looking smaller crater. The 2-km-wide eastern caldera contained a steep-walled inner crater whose floor prior to the 2003 eruption was only 68 m above sea level. Sparseness of vegetation on the most recent lava flows on Anatahan had indicated that they were of Holocene age, but the first historical eruption of Anatahan did not occur until May 2003, when a large explosive eruption took place forming a new crater inside the eastern caldera.


BATU TARA Komba Island (Indonesia) 7.792°S, 123.579°E; summit elev. 748 m

Based on a pilot report and observations of satellite imagery, the Darwin VAAC reported that during 6-8 and 10-11 August ash plumes from Batu Tara rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted W and NW.

Geologic Summary. The small isolated island of Batu Tara in the Flores Sea about 50 km north of Lembata (formerly Lomblen) Island contains a scarp on the eastern side similar to the Sciara del Fuoco of Italy's Stromboli volcano. Vegetation covers the flanks of Batu Tara to within 50 m of the 748-m-high summit. Batu Tara lies north of the main volcanic arc and is noted for its potassic leucite-bearing basanitic and tephritic rocks. The first historical eruption from Batu Tara, during 1847-52, produced explosions and a lava flow.


CHAITEN Southern Chile 42.833°S, 72.646°W; summit elev. 1122 m

Based on web camera views, SIGMET reports, observations of satellite imagery, and information from the Puerto Montt Flight Information Region (FIR), the Buenos Aires VAAC reported that during 7-8 August ash plumes from Chaitén rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted E and NE.

Geologic Summary. Chaitén is a small, glacier-free caldera with a Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf of Corcovado. A pyroclastic-surge and pumice deposit considered to originate from the eruption that formed the elliptical 2.5 x 4 km wide summit caldera was dated at about 9400 years ago. A rhyolitic, 962-m-high obsidian lava dome occupies much of the caldera floor. Obsidian cobbles from this dome found in the Blanco River are the source of prehistorical artifacts from archaeological sites along the Pacific coast as far as 400 km away from the volcano to the north and south. The caldera is breached on the SW side by a river that drains to the bay of Chaitén, and the high point on its southern rim reaches 1122 m.


CHIKURACHKI Paramushir Island 50.325°N, 155.458°E; summit elev. 1816 m

Based on observations of satellite imagery, KVERT reported that eruptive activity from Chikurachki continued during 1-8 August. Ash plumes drifted more than 60 km SE, W, and N during 1-3 August. The level of seismicity was unknown because Chikurachki lacks dedicated seismic instruments. The Level of Concern Color Code remained at Orange.

Geologic Summary. Chikurachki, the highest volcano on Paramushir Island in the northern Kurils, is actually a relatively small cone constructed on a high Pleistocene volcanic edifice. Oxidzed scoria deposits covering the upper part of the young cone give it a distinctive red color. Lava flows from 1816-m-high Chikurachki reached the sea and form capes on the NW coast; several young lava flows also emerge from beneath the scoria blanket on the eastern flank. The more erosionally modified Tatarinov group of six volcanic centers is located immediately to the S of Chikurachki. Tephrochronology gives evidence of only one eruption in historical time from Tatarinov, although its southern cone contains a sulfur-encrusted crater with fumaroles that were active along the margin of a crater lake until 1959.


CLEVELAND Chuginadak Island 52.825°N, 169.944°W; summit elev. 1730 m

On 6 August, AVO reported that the thermal anomalies noted at Cleveland's summit and on the W, S, and SE flanks had decreased in intensity since first noted on 21 July, indicating that the lava flows slowed or stopped. The Volcanic Alert Level was lowered to Advisory and the Aviation Color Code to Yellow. During 7-10 August, a weak thermal anomaly at the summit was intermittently visible when not obscured by clouds and drifting ash from the eruption of Kasatochi (about 400 km WSW). On 11 August, thermal anomalies on satellite imagery indicated that lava flowed down the flanks. The Volcano Alert Level was raised to Watch and the Aviation Color Code to Orange. On 12 August, an ash plume rose to an altitude of 7.6 km (25,000 ft) a.s.l. and drifted 100 km SW.

Geologic Summary. Symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited dumbbell-shaped Chuginadak Island in the east-central Aleutians. The 1,730-m-high stratovolcano is the highest of the Islands of Four Mountains group and is one of the most active in the Aleutians. Numerous large lava flows descend its flanks. It is possible that some 18th to 19th century eruptions attributed to Carlisle (a volcano located across the Carlisle Pass Strait to the NW) should be ascribed to Cleveland. In 1944 Cleveland produced the only known fatality from an Aleutian eruption. Recent eruptions from Mt. Cleveland have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.


KARYMSKY Eastern Kamchatka 54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that seismic activity at Karymsky was above background levels during 1-8 August and possibly indicated that explosions produced ash plumes to an altitude of 3.1 km (10,200 ft) a.s.l. Observations of satellite imagery revealed a thermal anomaly in the crater on 2 August; clouds inhibited views on other days. The Level of Concern Color Code remained at Orange.

Based on observations of satellite imagery and information from KEMSD, the Tokyo VAAC reported that on 11 August an eruption plume rose to an altitude of 3.4 km (11,000 ft) a.s.l.

Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon years ago. Construction of the Karymsky stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater. Most seismicity preceding Karymsky eruptions has originated beneath Akademia Nauk caldera, which is located immediately S of Karymsky volcano and erupted simultaneously with Karymsky in 1996.


KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

HVO reported that during 6 and 9-12 August lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entry. Occasional explosions and surface lava flows were noted near the ocean entry. A small fountain in a lava pond at the top of one of the rootless shields was observed on 10 August. The sulfur dioxide emission rate at Pu'u 'O'o was 1,700 and 2,400 tonnes per day on 8 and 9 August, respectively; the average background rate is about 2,000 tonnes per day.

During the reporting period, Kilauea earthquakes were variously located beneath Halema'uma'u crater, along the Koa'e fault system, SE and W of the caldera, along the S-flank faults, and along the E and SW rift zones. Beneath Halema'uma'u crater, up to 100 small earthquakes per day (background is 20-40) also occurred but were too small to be located more precisely. The vent in Halema'uma'u crater continued to produce a mainly white plume with minor ash content that drifted SW. The plume was occasionally tinged brown. Night-time incandescence was seen at the base of the plume rock-clattering sounds were heard in the vicinity of the crater. The sulfur dioxide emission rate was high at 900 tonnes per day on 7 August. The pre-2008 background rate was 150-200 tonnes per day.

Geologic Summary. Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed of lava flows less than about 1,100 years old; 70% of the volcano's surface is younger than 600 years. A long-term eruption from the East rift zone that began in 1983 has produced lava flows covering more than 100 sq km, destroying nearly 200 houses and adding new coastline to the island.


KRAKATAU Indonesia 6.102°S, 105.423°E; summit elev. 813 m

According to a news article, eruptions from Anak Krakatau increased in frequency during 10-11 August. On 12 August, monitoring personnel reported that active lava flows and emissions of thick "smoke" continued but that the frequency of earthquakes and eruptions had declined.

Geologic Summary. Renowned Krakatau volcano lies in the Sunda Strait between Java and Sumatra. Collapse of the ancestral Krakatau edifice, perhaps in 416 AD, resulted in a 7-km-wide caldera. Remnants of this volcano formed Verlaten and Lang Islands; subsequently Rakata, Danan and Perbuwatan volcanoes were formed, coalescing to create the pre-1883 Krakatau Island. Caldera collapse during the catastrophic 1883 eruption destroyed Danan and Perbuwatan volcanoes, and left only a remnant of Rakata volcano. The post-collapse cone of Anak Krakatau (Child of Krakatau), constructed within the 1883 caldera at a point between the former cones of Danan and Perbuwatan, has been the site of frequent eruptions since 1927.


OKMOK Fox Islands 53.43°N, 168.13°W; summit elev. 1073 m

AVO scientists observed the eruption of Okmok during a visit to Umnak Island on 2 and 3 August. They saw significant ashfall that had accumulated in the caldera and on the upper flanks, lahars and lahar deltas that formed in drainages from the SE to the NE flank, and continuous ash jets being emitted from three or more vents in the vicinity of Cone D in the NE sector of the caldera. Elevated seismicity was detected during 6-8 August, and declined on 9 August. According to observations of satellite imagery, steam plumes possibly containing ash rose to altitudes below 4.6 km (15,000 ft) a.s.l. during 9-10 August. On 11 August, steam plumes rose to altitudes of less than 6.1 km (20,000 ft) a.s.l. and drifted SE. Ash plumes that rose to around a hundred meters above the crater were reported by an observer in Nikolski (80 km SW). These plumes were not detected on satellite imagery due to cloud cover. On 12 August, a pilot reported an ash plume at an altitude of 4.6 km (15,000 ft) a.s.l. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Geologic Summary. The broad, basaltic Okmok shield volcano, which forms the NE end of Umnak Island, has a dramatically different profile than most other Aleutian volcanoes. The summit of the low, 35-km-wide volcano is cut by two 10-km-wide calderas formed during eruptions about 8,250 and 2,400 years ago that produced dacitic pyroclastic flows that reached the coast. Numerous satellitic cones and lava domes dot the flanks of the volcano down to the coast. Some of the post-caldera cones show evidence of wave-cut lake terraces; the more recent cones, some of which have been active historically, were formed after the caldera lake disappeared. Hot springs and fumaroles are found within the caldera and at Hot Springs Cone, 20 km to the SW. Historical eruptions have occurred since 1805 from cinder cones within the caldera.


PITON DE LA FOURNAISE Reunion Island 21.231°S, 55.713°E; summit elev. 2632 m

OVPDLF reported that a small seismic crisis beneath the summit of Piton de la Fournaise lasted about 10 minutes on 4 August. The strongest earthquake was a M 1.

Geologic Summary. Massive Piton de la Fournaise shield volcano on the island of Réunion is one of the world's most active volcanoes. Most historical eruptions have originated from the summit and flanks of a 400-m-high lava shield, Dolomieu, that has grown within the youngest of three large calderas. This depression is 8 km wide and is breached to below sea level on the eastern side. More than 150 eruptions, most of which have produced fluid basaltic lava flows within the caldera, have been documented since the 17th century. The volcano is monitored by the Piton de la Fournaise Volcano Observatory, one of several operated by the Institut de Physique du Globe de Paris.

RABAUL New Britain 4.271°S, 152.203°E; summit elev. 688 m

RVO reported that ash plumes from Rabaul caldera's Tavurvur cone continued to be emitted during 4-10 August. Ashfall was reported in areas NW. Occasionally incandescence at the summit was observed and roaring noises were reported. Incandescent lava fragments were ejected along with some of the more forceful ash emissions. Based on observations of satellite imagery and information from RVO, the Darwin VAAC reported that during 11-12 August, low-level ash plumes rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted NW.

Geologic Summary. The low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbor. The outer flanks of the 688-m-high asymmetrical pyroclastic shield volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km caldera is widely breached on the E, where its floor is flooded by Blanche Bay.Two major Holocene caldera-forming eruptions at Rabaul took place as recently as 3,500 and 1,400 years ago. Three small stratovolcanoes lie outside the northern and NE caldera rims. Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on the caldera floor near the NE and western caldera walls. Several of these, including Vulcan cone, which was formed during a large eruption in 1878, have produced major explosive activity during historical time. A powerful explosive eruption in 1994 occurred simultaneously from Vulcan and Tavurvur volcanoes and forced the temporary abandonment of Rabaul city.


REVENTADOR Ecuador 0.077°S, 77.656°W; summit elev. 3562 m

The IG reported that steam-and-gas from Reventador was emitted during 6-8 August. Incandescence from the crater was observed at night on 8 August.

Geologic Summary. Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well E of the principal volcanic axis. It is a forested stratovolcano that rises above the remote jungles of the western Amazon basin. A 3-km-wide caldera breached to the E was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1,300 m above the caldera floor. Reventador has been the source of numerous lava flows as well as explosive eruptions that were visible from Quito in historical time. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the caldera.


SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that on 10 August an eruption plume from Sakura-jima rose to an altitude greater than 2.7 km (9,000 ft) a.s.l. and drifted NW.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was associated with the formation of the 17 x 23-km-wide Aira caldera about 22,000 years ago. The construction of Sakura-jima began about 13,000 years ago and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4,850 years ago, after which eruptions took place at Minami-dake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.


SEMERU Eastern Java (Indonesia) 8.108°S, 112.92°E; summit elev. 3676 m

Based on information from CVGHM, the Darwin VAAC reported that on 7 August ash plumes from Semeru rose to an altitude of 4.3 km (14,100 ft) a.s.l. and that incandescent material was ejected from the crater. CVGHM indicated that the activity was normal; the Alert Level remained at 2 (on a scale of 1-4).

Geologic Summary. Semeru is the highest volcano on Java and one of its most active. The symmetrical stratovolcano rises abruptly to 3,676 m above coastal plains to the S and lies at the southern end of a volcanic massif extending N to the Tengger caldera. Semeru has been in almost continuous eruption since 1967. Frequent small-to-moderate Vulcanian eruptions have accompanied intermittent lava dome extrusion, and periodic pyroclastic flows and lahars have damaged villages below the volcano. A major secondary lahar on 14 May 1981 caused more than 250 deaths and damaged 16 villages.


SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev. 3283 m

KVERT reported that seismic activity at Shiveluch was slightly above background levels during 1-8 August, and possibly indicated that ash plumes from explosions rose to an altitude of 4.6 km (15,100 ft) a.s.l. on 6 August. Observations of satellite imagery revealed a thermal anomaly on the lava dome during 1-3 August. The Level of Concern Color Code remained at Orange.

Geologic Summary. The high, isolated massif of Shiveluch volcano (also spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group and forms one of Kamchatka's largest and most active volcanoes. The currently active Molodoy Shiveluch lava-dome complex was constructed during the Holocene within a large breached caldera formed by collapse of the massive late-Pleistocene Strary Shiveluch volcano. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. During the 1990s, intermittent explosive eruptions took place from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and 1964.


SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

MVO reported that seismic levels from Soufrière Hills were relatively low during 1-8 August. Sulfur dioxide emissions (tons per day) were significantly higher than emissions prior to the partial lava-dome collapse on 28 July. Unconfirmed reports indicated the presence of an ash plume on 3 August. A small ash cloud was seen on 7 August.

Further investigation of the 28 July event revealed that the total amount of material that collapsed from the dome was about 200,000-300,000 cubic meters. Satellite radar images indicated that the vent above Gages wall was enlarged by the explosion to about 150 x 60 meters, elongated E-W. Precautionary access restrictions for areas in and around Belham valley were lifted because evidence suggested that the dome had not been destabilized due to the event.

A new Hazard Level System, designed by MVO and Disaster Management Coordination Agency (DMCA) in consultation with the Government of Montserrat and community groups, was implemented on 8 August. The system divides the southern two-thirds of the island into six zones, and includes two Maritime Exclusion Zones. The Hazard Level ranges from 1-5 and is set by the National Disaster Preparedness, Response, and Advisory Committee (NDPRAC) with advice from MVO. The Hazard Level restricts access into each of the zones depending on the number assigned and is unrelated to the Alert Level. The current Hazard Level was 3.

Geologic Summary. The complex dominantly andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. English's Crater, a 1-km-wide crater breached widely to the E, was formed during an eruption about 4,000 years ago in which the summit collapsed, producing a large submarine debris avalanche. Block-and-ash flow and surge deposits associated with dome growth predominate in flank deposits at Soufrière Hills. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but with the exception of a 17th-century eruption that produced the Castle Peak lava dome, no historical eruptions were recorded on Montserrat until 1995. Long-term small-to-moderate ash eruptions beginning in that year were later accompanied by lava-dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing major social and economic disruption.



SUWANOSE-JIMA Ryukyu Islands (Japan) 29.635°N, 129.716°E; summit elev. 799 m

Based on reports from JMA, the Tokyo VAAC reported that on 7 August an eruption plume from Suwanose-jima rose to an altitude of 1.2 km (4,000 ft) a.s.l.

Geologic Summary. The 8-km-long, spindle-shaped island of Suwanose-jima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. Only about 50 persons live on the sparsely populated island. The summit of the volcano is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. Suwanose-jima, one of Japan's most frequently active volcanoes, was in a state of intermittent Strombolian activity from On-take, the NE summit crater, that began in 1949 and lasted nearly a half century. The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, after which the island was uninhabited for about 70 years. The SW crater produced lava flows that reached the western coast in 1813, and lava flows reached the eastern coast of the island in 1884.


TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

The IG reported that during 6-8 August, explosions from Tungurahua were detected by the seismic network. Although clouds mostly prevented visual observations, steam-and-ash plumes were observed; on 6 August, ash plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted W. Ashfall was reported in areas to the SW.

Geologic Summary. The steep-sided Tungurahua stratovolcano towers more than 3 km above its northern base. It sits ~140 km S of Quito, Ecuador's capital city, and is one of Ecuador's most active volcanoes. Historical eruptions have all originated from the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. The last major eruption took place from 1916 to 1918, although minor activity continued until 1925. The latest eruption began in October 1999 and prompted temporary evacuation of the town of Baños on the N side of the volcano.
[link to www.volcano.si.edu]

Alaska Volcano Observatory
Current Status Report
Wednesday, August 13, 2008 1:24 PM AKDT (21:24 UTC)


KASATOCHI VOLCANO
52°10'9" N 175°30'41" W, Summit Elevation 1030 ft (314 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

The remnant volcanic ash cloud from the eruption of Kasatochi volcano last week has largely dissipated and is no longer detected over southeast Alaska in satellite data. A volcanic gas and aerosol cloud from the eruption persists over parts of North America. Seismic activity at Kasatochi volcano is still being detected by the AVO seismic network on Great Sitkin Island 25 miles to the west.

AVO has received no new information about ash emissions or activity from passing pilots or mariners. The volcano is still quite restless and renewed eruptive activity is still possible.

CLEVELAND VOLCANO
52°49'20" N 169°56'42" W, Summit Elevation 5676 ft (1730 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Volcanic unrest continues at Cleveland volcano. Cloudy conditions in the region have prohibited satellite observations today and AVO has received no new information or observations about activity at Cleveland.
Small ash bursts and low-level ash plumes may resume at the volcano. It is also possible for larger, higher reaching plumes to be produced without warning.

OKMOK VOLCANO
53°23'49" N 168°9'58" W, Summit Elevation 3520 ft (1073 m)
Current Aviation Color Code: ORANGE
Current Volcano Alert Level: WATCH

Eruptive activity continues at Okmok Volcano. The intensity of activity has been relatively steady over the past day. A weak low-level ash cloud was observed in satellite data this morning, but likely did not extend more than 15,000 feet above the volcano.



Minor ash fall may occur over parts of Umnak Island.

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. Augustine, Iliamna, Redoubt, Wrangell, Gareloi, Great Sitkin, Makushin, Fisher, Shishaldin, Isanotski, Pavlof, Veniaminof, Ugashik-Peulik, Griggs, Snowy, Fourpeaked, Aniakchak, Tanaga, Kanaga, Akutan, Westdahl, Dutton, Ukinrek Maars, Martin, Mageik, Trident, Katmai, Novarupta, Spurr, and Korovin 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 volcano.

Please see [link to www.avo.alaska.edu] for complete definitions of Aviation color codes and Volcano alert levels.

VOLCANO INFORMATION ON THE INTERNET: [link to www.avo.alaska.edu]
RECORDING ON THE STATUS OF ALASKA'S VOLCANOES (907) 786-7478

CONTACT INFORMATION:
Chris Waythomas, Acting Scientist-in-Charge, USGS
[email protected], (907)786-7497

Jon Dehn, Acting Coordinating Scientist, UAFGI
[email protected] (907) 474-6499

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 VOLCANO OBSERVATORY DAILY UPDATE
Wednesday, August 13, 2008 07:57 HST (Wednesday, August 13, 2008 17:57 UTC)


KILAUEA VOLCANO (CAVW#1302-01-)
19.42°N 155.29°W, Summit Elevation 4091 ft (1247 m)
Volcano Alert Level: WATCH
Aviation Color Code: ORANGE

This report on the status of Kilauea volcanic activity, in addition to maps, photos, and webcam images (available using the menu bar above), was prepared by the USGS Hawaiian Volcano Observatory (HVO). Hawai`i Volcanoes National Park status can be found at [link to www.nps.gov] or 985-6000. Hawai`i County Viewing Area status can be found at [link to www.lavainfo.us] or 961-8093.

Activity Summary for last 24 hours: Kilauea summit continued to produce increased amounts of ash and elevated amounts of sulfur dioxide gas from the Halema`uma`u vent. At the east rift eruption site, Pu`u `O`o cone continued to produce elevated amounts of sulfur dioxide gas; vog, probably from Pu`u `O`o, was reported in Hilo this morning; the TEB eruption has resumed with lava flowing through tubes to the ocean and supplying several surface flows.

Last 24 hours at Kilauea summit: The normally-white plume turned brown at least twice yesterday morning in response to local earthquakes. Overnight, incandescence was very weak. Despite the weak glow, NPS interpretation staff were able to record two possible winks not associated with earthquakes around 7:30 pm.

A white, sometimes brownish, plume is rising from the Halema`uma`u vent at least 700 m straight up before being blown eastward toward Mauna Loa; SO2 concentrations have already peaked at HVO, Volcano Golf Course, and Kulani Prison this morning. GOES-WEST imagery shows the plume going west this morning before veering to the southwest starting at 06:30. Sulfur dioxide emission rates remained elevated, variable, and unaffected by the wind change; the most recent average measurement was 600 tonnes/day on August 12 compared to 900 tonnes/day on August 7 and a pre-2008 background rate between 150-200 tonnes/day.

Even with weak winds, increased amounts of ash were collected beneath the plume this morning underscoring that the plume has been carrying more ash over the last few days. Rock impact and rushing sounds were more evident near the vent when not drowned out by howling trade winds.

The summit tiltmeter network recorded slowed deflation. The network of GPS receivers that span the summit caldera recorded contraction across the caldera.

Seismic tremor remained at moderate levels with no episodic bursts. The number of RB2S2BL earthquakes beneath Halema`uma`u Crater continued to decline and are near background values. Two earthquakes were located beneath the summit area, one on Koa`e faults, and one beneath the upper east rift zone.

Last 24 hours at the middle east rift zone vents and flow field: Magma continued to degas through Pu`u `O`o Crater resulting in an emission of 2,400 tonnes/day of sulfur dioxide on August 8, down from a high of 7,100 tonnes/day on July 18 and near background values of about 2,000 tonnes/day. Visible vog has been reported in Hilo this morning. No incandescence was observed within the crater last night.

The tiltmeter on the north side of Pu`u `O`o cone recorded deflation. GPS receivers recorded no change in distance across the crater. Seismic tremor levels were at background levels near Pu`u `O`o but remain elevated near the TEB vent.

Lava from the TEB vent and the rootless shield field through tubes to the ocean. The only incandescence visible on the flow field above the pali was from from the upper rootless shield complex. At least one flow finger remained active on the coastal plain yesterday and was advancing through the kipuka immediately west of the viewing area. GOES-WEST imagery continued to show a thermal anomaly suggesting surface flows are still active at the coast this morning. There were three active entries yesterday, one on either side of the main Waikupanaha entry.
[link to volcano.wr.usgs.gov]

Chaiten area airport north view. Kinda weird. Yesterday, a cloud cover came in that looked a bit like the plume changing direction for the airport and the camera lens got choked over with something completely obstructing the view. When I checked satellite, it did show a cloud formation coming in over Chile. No one has cleared the lens as of yet.

[link to www.aipchile.cl]

There haven't been any new updates from Sernageomin SInce the 4th for Chaiten and the 2nd for Llaima.

Hrmmm... Looks like the volcanoes under the arctic are potentially fixing for some activity. Not sure if we'd actually be able to find a site that would cover that, though. But, interesting activity there.

4.9 2008/08/14 10:37:51 83.314 117.575 10.0 NORTH OF SEVERNAYA ZEMLYA
4.5 2008/08/14 09:29:13 83.581 114.926 10.0 NORTH OF SEVERNAYA ZEMLYA
4.4 2008/08/14 05:59:21 83.558 114.438 10.0 NORTH OF SEVERNAYA ZEMLYA
5.6 2008/08/13 18:30:57 83.538 114.132 10.0 NORTH OF SEVERNAYA ZEMLYA
5.4 2008/08/13 08:35:02 83.708 114.752 10.0 NORTH OF SEVERNAYA ZEMLYA
4.4 2008/08/10 10:05:14 83.707 113.747 10.0 NORTH OF SEVERNAYA ZEMLYA

opps... Link
[link to earthquake.usgs.gov]

There does seem to be a pretty good cloud cover over Chile right now. I'll check the cam later today, but I have a feeling we won't be able to distinguish cloud from plume today if the lens is cleared.



Chaitén Update 51
[link to www.seablogger.com]
Thursday, 14 Aug 08, volcanoes
Chilean official Werner Luis publishes a Spanish-language blog with updates and photographs of the Chaitén eruption. Today I see some interesting new information there: analysis of newly-fallen ash indicates a change in chemistry, specifically a lower silica content. You may recall that the initial explosions deposited ash exceptionally high in silica, and low in SO2. The latter is deemed to have more climatological impact when injected to the stratosphere.

Of course the clear implication is that magma from a new, deeper source has reached the surface — an interpretation consistent with the seismic pattern of recent weeks. The volcano has now entered a second eruptive phase. So far there have been no big explosions. We will see nothing today. Rain is washing the ash off the webcam, little by little, but the weather is likely to remain bad and the viewing poor to nil.

I will check the visible satellite image before South American sundown, and see whether plume is punching through the cloud deck. If it is, this post will get an update. BTW, last week’s Aleutian eruption put more SO2 in the stratosphere than any volcanic blast since Cerro Hudson in 1991.