
Map of Augustine GPS and Seismic Stations
The backbone of AVO's volcano monitoring program consists of networks of continuously recording seismometers installed at selected volcanoes. Seismic data

Seismometer installed at Mt. Spurr
are relayed to AVO facilities in Fairbanks and Anchorage where they are analyzed both automatically and by analysts. Initially, AVO concentrated
its monitoring efforts on the four Cook Inlet volcanoes because they are closest to Alaska population centers. In response to the increasing
hazard to aviation from volcanic ash, AVO started a program of expansion in 1996 to other volcanoes in the Aleutian Islands and on the Alaska Peninsula,
and now monitors more than 20 volcanoes. Volcanic unrest, caused by the migration of magma and other fluids through the earth's crust, is
heralded by increased seismicity, often months to weeks before eruption. Because the seismometers provide a continuous data stream the onset of
explosive eruptions can be detected quickly in most cases and appropriate warnings issued. An electronic alarm system is employed during non-business
hours.

Landsat 5 view of 1986 Augustine eruption.
Satellite imagery provides information which complements seismic monitoring at those volcanoes with seismic networks, and is the only source of routine monitoring
information at those without. AVO analyzes available satellite data twice daily for thermal anomalies and ash plumes at about 80 volcanoes
in the north Pacific. Thermal anomalies at volcanic vents have been detected up to several weeks before large eruptions. Volcanic ash
erupted into the atmosphere is a serious hazard to jet aircraft because it can cause their engines to shut down as it is ingested. By analyzing
satellite imagery and working with the National Weather Service to predict where winds will carry the ash, AVO assists the Federal Aviation Administration
in warning aircraft of areas to avoid.
Space-based deformation monitoring is an emerging technique. AVO operates a network of telemetered GPS receivers at Augustine Volcano, in lower Cook Inlet
that provide a continuous record of ground deformation. AVO also conducts periodic field-based GPS surveys as well as measuring deformation
with satellite radar interferometry (InSAR) techniques. These techniques are providing important information about inflation and deflation of volcanoes,
but are not yet evolved enough for routine real-time monitoring of many volcanoes.
During eruptions and under conditions of heightened concern, the crisis center at AVO-Anchorage becomes directly responsible for all AVO activities concerning the
emergency. AVO is the principal point of contact for information on volcanic activity and hazards assessment for government agencies, the media, and the public. At
all times and especially during volcanic emergencies, AVO maintains close communication links with other critical agencies such as National Weather Service, Federal
Aviation Administration, and Alaska State agencies who all issue additional hazard messages and guidance as needed.
AVO's component agencies have a statutory obligation to distribute information regarding volcanic activity in Alaska. Currently, AVO distributes a weekly summary of
volcanic activity in Alaska each Friday. During eruptions, written statements that include the location, time, size of the eruption, and narrative descriptions of
projected plume paths, are distributed by AVO to federal, state, and local government agencies, the public, the media, commercial airlines, and others by pre-programmed
facsimile machines and electronic mail systems. Anyone can subscribe to receive these messages through the Volcano Notification Service by signing up at this web site:
http://volcanoes.usgs.gov/vns/.
Additional notices and updates are prepared as needed, depending on changes in volcanic activity or hazards. AVO also maintains two recorded message lines (numbers)
which are updated with summations of the latest status of volcanic activity. AVO answers many calls from the public and as time allows, gives interviews with media,
tours of the AVO facility, and deliver presentations to schools and other groups. The AVO web site is a source of selected images from our vast photo and video library
of volcanic phenomena through the years.
To assist our partners responsible for reporting on volcanoes in the Russian Far East, AVO's web page mirrors alert messages from the Kamchatka Volcanic Eruption
Response Team and the Sakhalin Volcanic Eruption Response Team. During large Russian eruptions in Kamchatka or the Kuriles, AVO scientists may assist in analysis
of eruption clouds to inform the aviation community of airborne ash hazard.