Volcano Hazards

Pictured above: Eruption cloud from Redoubt Volcano, Lake Clark National Park, Alaska. Photograph by R.J. Clucas on April 21, 1990. This volcano is monitored with onsite instruments and by remote sensing.

The fascinating beauty of active volcanic processes and pristine volcanic landscapes inspired the nation to set aside park lands surrounding many of the most active and dangerous volcanoes in the western United States. Potential volcanic dangers to National Park Service (NPS) staff, visitors, and surrounding communities may include explosive eruptions, fiery avalanches of hot ash (pyroclastic flows), giant mudflows of ash (lahars), sudden slope collapse, lava flows, ash clouds, volcanic gas emissions, and earthquakes. The USGS Volcano Hazards Program provides assistance to NPS managers by monitoring volcanic unrest, assessing volcano hazards, and responding to volcano crises.

Pictured above: Lava fountain, Kilauea, Hawai'i Volcanoes NP, 1993. USGS scientist has just collected a sample of the newly erupted lava for analysis.

Monitoring Unrest:

To provide short-term prediction of geologic disasters and rapidly characterize their effects, the USGS monitors volcano unrest in the most dangerous volcanic centers within and adjacent to National Park Service lands. USGS scientists provide timely warnings to land managers and public safety agencies to mitigate damage and loss of life and property resulting from volcanic eruptions.

Assessing Volcano Hazards:

The USGS also assesses the full range of potential hazards at specific volcanic centers. Hazard assessments include a description of the eruptive history of a given volcano, explanations of likely eruption scenarios, and determination of probable impact zones for the range of expected hazards. Hazard assessments assist NPS development of safety and emergency response plans, resource management plans, and public awareness programs.

Pictured above: Illustration showing geologic hazards associated with volcanoes.

Responding to Crises:

The USGS, in partnership with the U.S. Office of Foreign Disaster Assistance, maintains the world's only rapid- response volcano crisis team: a team of volcano specialists and a cache of equipment that can be quickly dispatched to an awakening volcano if needed. This experienced team works with local land managers and public safety agencies to save lives and property. The USGS collaborates in advance with U.S. federal and local land managers and emergency management agencies to prepare Volcano Hazard Response Plans that clearly define the roles and responsibilities of various agencies.

Many kinds of volcanic activity can endanger the lives of people and property both close to and far away from a volcano. Most of the activity involves the explosive ejection or flowage of rock fragments and molten rock in various combinations of hot or cold, wet or dry, and fast or slow. Some hazards are more severe than others depending on the size and extent of the event taking place and whether people or property are in the way. And although most volcano hazards are triggered directly by an eruption, some occur when a volcano is quiet.