From the National Park Service:
Mount Rainier National Park will conduct a test of the Geohazard Warning Siren at the Nisqually Entrance on Saturday, February 28, 2009, at 12:00, noon. The park is testing the new system and attempting to familiarize visitors, local residents and staff with the siren in the event of an actual geohazard.
The Geohazard Warning Siren is designed to warn park staff and visitors of sudden geohazards, including lahars and smaller debris flows. Without warning, debris flows and glacial outburst floods can occur at any time, eroding stream banks and scouring everything in their paths, including rocks and trees. In case such an emergency occurs within the park, it is recommended that visitors head up hill, away from rivers and streams, and rising water. Avoid crossing any running water once the siren has been activated. Geohazard sirens are located at Cougar Rock Campground, Longmire, and Nisqually Entrance.
Some residents of Pierce and Lewis Counties, living outside of the park might hear the siren once activated. If you are a resident of Pierce County, it is recommended that you contact the Pierce County Department of Emergency Management at 253-798-6595 for more information on Mount Rainier related geohazards. Additionally, you can read information from the Pierce County Department of Emergency Management on their website at www.piercecountywa.org/prepare . Residents of Lewis County can contact the Lewis County Sheriff’s Office, Division of Emergency Management at
360-740-1151 and also check on line at
https://fortress.wa.gov/lewisco/home/LC/EM/Default.aspx?lcID=31 for more information on Mount Rainier related geohazards.
For more information on geohazards and to listen to an audio demonstration of the Geohazard Siren tone at Mount Rainier National Park visit our website at http://www.nps.gov/mora/planyourvisit/yoursafety.htm.
Active steam vents, periodic earth tremors, and historic eruptions provide evidence that Mount Rainier is sleeping, not dead. Seismic monitoring stations around the mountain should provide days or weeks of advance warning of impending eruptions. Other geologic hazards, however, can occur with little to no warning. These include debris flows and rockfalls.