Crisis GIS—Preparing for the Next Volcanic Eruption in the United States

The Volcano Hazards Program (VHP) of the U.S. Geological Survey is charged with monitoring the nation's high-risk volcanoes and issuing timely warnings of potential volcanic hazards to responsible emergency management authorities and the affected population. VHP GIS specialists are developing a Crisis GIS plan to ensure rapid, reliable delivery of spatial and ancillary information for data analysis and visualization at any required location during a volcanic crisis or event within the United States.

A well-designed and constructed GIS of U.S. volcano information will be invaluable during a crisis when timely analysis and communication of volcanic hazards are most critical. An effective Crisis GIS must have the capacity to store multiple large datasets including base layer data, elevation data, geologic mapping, hazard assessment maps, satellite data, aerial photography, and volcano-monitoring data for volcanoes around the United States. The system must also be readily accessible to VHP GIS specialists stationed throughout the country and have the capacity to produce electronic and paper maps illustrating volcano hazards and potentially threatened areas. These products will be vital to VHP for visualizing and analyzing the situation and communicating with emergency managers, the media, and the public during the next volcanic crisis.

On March 23, 2004, a swarm of small earthquakes of magnitude no greater than 1.5 began in the Three Sisters volcanic center in the Oregon Cascade Range. The earthquakes were caused by the continuing intrusion of a modest amount of magma that has been accumulating and causing the ground to uplift since late 1997 as shown on satellite images. The earthquake swarm lasted for nearly two days. VHP GIS specialists working at the Cascades Volcano Observatory were busy for several days producing maps and perspective views of the Three Sisters region showing the area of uplifted ground and the locations of earthquakes in the swarm.

The maps were used to visualize and analyze the event and proved valuable to VHP scientists assessing the situation. Although this was a short-lived event, it demonstrated that GIS will be an integral part of VHP response to volcanic unrest in the future.