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NEWS ITEMS
2017
Bogoslof Volcano, Alaska: ongoing eruption through the Bering Sea Thank you Unalaska! Bogoslof Summary of Current Activity Bogoslof Summary of Current Activity, through 19 January 2017

2016
AVO studies resuspended volcanic ash from the Katmai region to Kodiak Island, Alaska Citizen Science - Volcanic Ash Collection Workshop and Public Talk, Kodiak January 30, 2016 Fieldwork at Iliamna and Spurr New publication highlights the importance of ash scrubbing in the evaluation of hazards from explosive eruptions

2015
Critical Volcano Monitoring Systems Returned to Operation in Alaska Resuspended Volcanic Ash from the Katmai Region to Kodiak Island Remobilized Katmai 1912 ash: community events and health hazard analysis Makushin 2015 Geology Blog Sixth Anniversary of the Redoubt 2009 Eruption Happy Anniversary, Shishaldin 1967 and 2014!

2014
New Publication on Aniakchak Volcano Available Online 25th Anniversary of the 1989-90 Eruption of Redoubt Volcano AVO geochemical database now available AVO Scientists Discuss Cook Inlet Volcanoes on Frontier Scientists TV Series Announcing new monitoring equipment for Cleveland volcano 22nd anniversary of Crater Peak (Mt Spurr) June 27 eruption Revised Alaska Interagency Operating Plan for Volcanic Ash Episodes Anniversary of Aniakchak 1931 eruption! April 19th - anniversary of Shishaldin 1999 and Pavlof 1986! Ground-coupled airwaves and explosion signals at Shishaldin 5th anniversary of the Redoubt 2009 eruption Loss of Critical Volcano Monitoring Information in Alaska NEW VOLCANO NUMBERING SYSTEM IMPLEMENTED Loss of Critical Volcano Monitoring Information in Alaska Report released: Geochemical investigations of the hydrothermal system on Akutan Island, July 2012

2013
24th Anniversary of the 1989-90 eruption of Redoubt Volcano Veterans Day slideshow Call for images from active and retired service members! AVO operations during lapse of federal government appropriations New Tool for Reporting Alaska Volcanic Ash Fall Allows Residents to Assist Scientific Monitoring 25 years monitoring Alaska volcanoes - press release

2012
AVO slideshow for Veterans Day Large ash eruptions: when volcanoes reshape valleys -- free public lecture Father Hubbard and the history of exploration in the Valley of Ten Thousand Smokes - free lecture Remote sensing and volcanoes - free public lecture The Great Eruption of 1912 - free public lecture Infrasound Detection of Volcanic Explosions Archaeology of Katmai area and the impact of past eruptions - free public lecture Historical Photography of the Great 1912 Eruption - free public lecture Catastrophic Eruptions and People -- free public lecture Eruption of an Island Volcano: Kasatochi, 2008 -- free public lecture Exploring the Plumbing System of Katmai Volcanoes Exploration of Katmai and the Valley of Ten Thousand Smokes - free public lecture Commemorative presentation in Kodiak: Be Prepared! Earthquakes Below Alaskan Volcanoes - free public lecture DisaStory - A Day of Oral History 1912 Katmai Eruption Children's Program Monitoring Alaska's Volcanoes - free public lecture Landmark volcano study: Katmai Centennial Perspectives free download Special activities on AVO's website for 1912 centennial Alaska Park Science - Volcanoes of Katmai and the Alaska Peninsula AVO at the Alaska Aviation Trade Show and Conference May 5-6 The Great Katmai Eruption of 1912 - a free lecture in Anchorage: April 24, 2012 The Great Katmai Eruption of 1912: A Century of Research Tracks Progress in Volcano Science April 25 -- The Novarupta - Katmai 1912 eruption: a free lecture in Fairbanks by Judy Fierstein Summer lecture series on Alaskan volcanism Poster contest celebrates anniversary of Katmai eruption! Mark your calendar: April 24 public lecture on the great Novarupta-Katmai eruption of 1912 An important volcanic anniversary in Alaska! PUBLISHED: The 2009 Eruption of Redoubt Volcano, Alaska

2011
2011 Alaska Interagency Operating Plan for Volcanic Ash Episodes now available How does Cleveland's lava dome compare to Redoubt's 2009 lava dome? Alaska Volcanoes Guidebook for Teachers

2010
New Fact Sheet on Kasatochi How big is the 2009 Redoubt lava dome?

2009
New map: Historically active volcanoes of Alaska Steaming at Augustine Sarychev Volcano: Active Volcanoes of the Kurile Islands Footage of Alaska's Redoubt Volcano taken on Monday, March 23, 2009. Pre-eruption footage of Redoubt Volcano, Saturday, March 20, 2009 Redoubt Volcano B-Roll Footage

2008
Kasatochi 2008 eruption summary 6th Biennial Workshop on Subduction Processes emphasizing the Kurile-Kamchatka-Aleutian Arcs Geophysical Institute, University of Alaska, Fairbanks, Alaska Chiginagak volcano's acid crater-lake continues to supply acidic, metal-laden water to salmon spawning habitat on the Alaska Peninsula ALASKA VOLCANOES - TEACHER ACTIVITY GUIDEBOOK & KIT 20 years of AVO Viewing earthquake information for Alaska volcanoes

2007
Pavlof webcam added Activity at Pavlof volcano Pavlof thermal anomaly AVO Scientists present at U.S. Department of Education Teacher-to-Teacher Workshop Cleveland webcam available Activity at Cleveland volcano Cleveland satellite images Sheveluch Eruption U.S. Geological Survey's alert notification system for volcanic activity KVERT Volcanic Warnings Ceased

2006
New alert system for volcanic activity Three new webcams added AGU presentations requested New webcam available
RESUSPENDED VOLCANIC ASH FROM THE KATMAI REGION TO KODIAK ISLAND
Resuspended Volcanic Ash from the Katmai Region to Kodiak Island
Posted: September 04, 2015

Figure 1. View southeast from Overlook Cabin looking over the VTTS. The pyroclastic and ash deposits that fill the valley remain nearly vegetation-free more than 100 years after the 1912 Novarupta-Katmai eruption. Photograph by Game McGimsey, AVO/USGS, June 10, 1991.

Volcanic ash isn't only a hazard during an eruptive event - in strong winds, loose ash can be picked up and reworked into dust clouds. Resuspension and transport of fine-grained volcanic ash from the Katmai National Park and Preserve region of Alaska has been observed and documented over the past several decades and has likely been occurring ever since the 1912 Novarupta-Katmai eruption. This eruption produced approximately 4 cubic miles (17 cubic kilometers) of ash deposits and 2.6 cubic miles (11 cubic kilometers) of pyroclastic material that filled nearby valleys, creating what is today known as the Valley of Ten Thousand Smokes. Ash in this valley is up to 660 feet (200 meters) thick and the valley remains almost entirely free of vegetation (fig. 1).
During the spring and fall, or whenever strong northwesterly winds blow over the snow-free landscape, the ash can be picked up (reworked) into dust clouds. The ash is especially susceptible to reworking when the ground is very dry. These dust clouds have been observed visually by individuals downwind and also in satellite imagery (figs. 2 and 3). These dust clouds are concentrated between 4,000 and 11,000 feet (1-3.4 kilometers) above sea level and can extend up to 155 miles (250 kilometers) over Shelikof Strait, parts of Kodiak Island, and over the Gulf of Alaska. Trace amounts of ash fallout (typically less than 1/32 inch or 1 mm) have been reported on communities on Kodiak Island. Samples show this fallout is primarily composed of volcanic ash.


Figure 2. MODIS Aqua 1-km resolution true color satellite image shows a resuspended ash cloud generated from high winds scouring the dry, unvegetated deposits in the VTTS. Image obtained November 29, 2010, courtesy of NASA.

What are the hazards associated with resuspended ash?
Clouds of resuspended volcanic ash have not been well studied and little is currently known about the amount or sizes of ash particles in the clouds. Like many other wind-related erosion events in Alaska, strong winds are able to pick up fine material, in this case volcanic ash rather than silt or sand. The clouds are composed of volcanic ash, which is primarily volcanic glass, and they appear similar to ash clouds from a volcanic eruption.
As resuspended ash is physically identical to ash produced in volcanic eruptions, even dilute clouds can pose hazards to human health and aircraft operation. The impact of fallout of resuspended ash is not well known and the largest resuspension events observed so far only produced fallout in trace amounts (less than 1/32 inch or 1 mm). It is not known if this amount presents an air quality issue and thus a public health hazard. The ash does create a hazard to aircraft flying at those elevations. The Alaska Volcano Observatory works closely with the National Weather Service, who has the responsibility to issue forecasts and statements of resuspended volcanic ash More information on volcanic ash is found at: http://volcanoes.usgs.gov/ash/.


Figure 3. Web camera image shows resuspended ash from the Katmai region on September 29, 2014.

How will I know about these events?
Take Home Points

  • These dust clouds are not caused by an active volcanic eruption.

  • These volcanic ash clouds are the result of high winds picking up loose volcanic ash from extensive deposits erupted over 100 years ago from the Novarupta vent on the Alaska Peninsula within Katmai National Park.

  • They can occur regularly in the spring and fall, or whenever strong northwesterly winds blow across the area coincident with extended periods of dry ground surface conditions.

  • Cloud heights have been estimated between 4,000 and 11,000 feet (1 - 3.4 kilometers) above sea level.

  • Clouds can extend up to about 155 miles (250 kilometers) over Shelikof Strait, parts of Kodiak Island and over the Gulf of Alaska.


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Page modified: December 2, 2016 10:12
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