Alaska is one of the most volcanically active regions on Earth, located at the far northern border of the Pacific Ocean, a vast, rugged area of critical importance to global commerce and national security. The more than 50 historically active volcanoes in this region have produced, on average, two explosive eruptions each year. In many cases, eruptions have generated towering clouds of volcanic ash and gas that have traveled thousands of miles downwind, dropping ash on communities as far as northern California and endangering air traffic across the entire continent.
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The Alaska Volcano Observatory (AVO) was founded in 1988 to issue warnings of volcanic activity in Alaska and to conduct scientific studies of volcanism in order to better anticipate hazards and understand patterns of unrest. Effectively monitoring dozens of volcanoes across 1,500 miles of harsh terrain presented enormous technical and logistical challenges. Over the course of 20 years, AVO, a collaborative project of the U.S. Geological Survey (USGS), the University of Alaska Fairbanks Geophysical Institute (UAFGI), and the Alaska Division of Geological and Geophysical Surveys (ADGGS), has successfully integrated scientific understanding of volcanoes and advances in technology to achieve this goal. AVO collaborates with the National Weather Service (NWS), the Federal Aviation Administration (FAA), and other key agencies and institutions to generate coordinated hazard messages and promote public safety. AVO also cooperates with citizens and land management agencies such as U.S. Fish and Wildlife Service and the National Park Service to work on public and private lands in Alaska.
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| Ascending eruption cloud from Redoubt Volcano as viewed to the west from the Kenai Peninsula. The mushroom-shaped plume rose from avalanches of hot debris (pyroclastic flows) that cascaded down the north flank of the volcano. A smaller, white steam plume rises from the summit crater. Photograph by R. Clucas, April 21, 1990. Image is courtesy of the photographer. |
AVO was founded only 18 months prior to the dramatic eruption of Redoubt Volcano, 210 miles southwest of Anchorage. A seismic network that became operational several months before the onset of activity alerted AVO to signs of a possible eruption less than a day before the eruption began. Correctly interpreting this critical information, AVO alerted government authorities and the public to begin emergency preparations. Repetitive explosive dome collapse events from Redoubt Volcano through April of 1990 produced dangerous ash clouds and fast-moving mudflows down the Drift River. Although mudflows threatened the important Drift River Oil Terminal, early warning by AVO prompted the safe evacuation of workers and the eventual enhancement of protective dikes around oil storage tanks.
Airborne volcanic ash is one of the greatest threats from eruptions in Alaska and neighboring Kamchatka (Russia). Every day, more than 250 flights and perhaps 30,000 people fly downwind or near more than 100 potentially active volcanoes from Alaska to Russia, a doubling of the air traffic 20 years ago. These 100 volcanoes produce dozens of dangerous ash clouds annually. Funding to install and maintain the monitoring networks of AVO has been a valuable investment in public safety. Since a near-disastrous meeting of a Boeing 747 and an ash cloud over Alaska in 1989, no damaging encounters have occurred along the north Pacific air routes
Twenty years of volcano research conducted by scientists and students at USGS, UAFGI, and ADGGS, have contributed important insights into how volcanoes work and how to harness new technology to monitor and more accurately forecast future hazardous eruptions. Among the scientific highlights of 20 years:
- The 2006 eruption at Augustine was preceded by nine months of increasing unrest that included escalating earthquake activity and six months of very slow inflation of the volcanic edifice that accompanied the accumulation and ascent of magma and provided the basis for the successful forecasting of this eruption.
- The application of Interferometric Synthetic Aperture Radar (InSAR), a powerful satellite-based tool for detecting tiny changes in the ground surface, has demonstrated that volcanoes are often in motion and the extent and style of deformation is highly variable and may be strongly dependant on magma composition.
- Twenty years of seismic monitoring of numerous Alaskan volcanoes has provided further insight into the relationship between deep long period earthquakes and magma migration. Identification of this process may provide a means to issue warnings with longer lead times than in the past at some volcanoes.
- Alaska
volcano seismic networks have also supported study of ‘triggering', or the
subtle response of volcanic plumbing systems to distant earthquakes around
the world.
- AVO is producing geologic maps and hazard assessments, as well as conducting detailed physical, chemical, and other studies of particularly important deposits and volcanoes to better understand how eruptions occur.
- Using high-pressure and temperature laboratory facilities at UAFGI and elsewhere, AVO scientists have probed the mysteries of crystallization, bubble growth, and magma ascent, all to better understand how volcanoes behave.
- AVO scientists have developed numerical models for volcanic processes of concern, such as the propagation of tsunamis formed during volcano flank collapse or pyroclastic flow entry into bodies of water.
AVO's dynamic website (http://www.avo.alaska.edu) contains extensive information about present and past volcanic eruptions in Alaska and is increasingly popular as a destination for real-time data about Alaska's restless volcanoes. AVO has created a 20th Anniversary webpage (http://www.avo.alaska.edu/avo20/) and is asking the public to contribute tales, poems, songs, artwork, or photos reflecting the public's participation or awe inspiring moments - how Alaska's volcanism has impacted them. In honor of our 20th Anniversary, later this month we will share some of the gems AVO has received to date.
The USGS, one of the three component agencies of AVO, serves the nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.
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| Map of the Pacific basin showing volcanoes active in the last 10,000 years as triangles (only the yellow ones have monitoring networks) and major flight corridors. |