Mount Rainier Volcano Lahar Warning System
Encyclopedia
The Mount Rainier Volcano Lahar Warning System is a loose-knit, emergency notification and warning system developed by the United States Geological Survey
in 1998, and now operated by the Pierce County
Department of Emergency Management and several cities . It is supposed to assist in the evacuation of the Puyallup River Valley in Washington state
in the event of a volcanic eruption from Mt. Rainier.
Mount Rainier
, an active volcano in Washington state
which last erupted in 1882, has occasionally buried sections of the Puyallup River valley in volcanic mudflow. Currently, more than 100,000 people live on the deposits of Mount Rainier lahar
s that have occurred within the last 6,000 years.
Geologists consider Mount Rainier the most dangerous mountain in the United States,
and the Geological Survey has estimated there is a 1-in-7 chance of a catastrophic lahar at Mount Rainier occurring in the next 75 years.
The Pacific Northwest Seismic Network (PNSN), operated by the University of Washington
, provides continuous monitoring of seismic activity in the area and is intended to provide first indication of volcanic unrest at Mount Rainier. However, while the PNSN is able to detect that a lahar-generating event has occurred, it is not able to determine the location or flow of debris. Beginning in 1998 a lahar-detection system consisting of five acoustic flow monitors was installed around Mount Rainier which would help identify the speed and direction of a lahar. Comprehensive coverage, which would require 30 to 40 such monitors, has yet to be installed.
Since 2000, the nascent lahar detection system has been operated by the Pierce County Department of Emergency Management which also has responsibility for coordination of public information and evacuation of areas of potential impact. Tacoma, at the mouth of the Puyallup, is only 37 miles (60 km) west of Mount Rainier, and moderately sized towns such as Puyallup
and Orting are only 27 and 20 miles (43 and 32 km) away, respectively.
The public alert component of the warning system is composed of a network of 26 siren
s owned by the municipalities in which they are located. The sirens are augmented by a Reverse 911
system maintained by the county and a dedicated emergency management radio station broadcasting at 1580AM. Directional signs in the area of potential impact are posted along pre-designated evacuation routes.
's that could be illuminated during a volcanic event are also being evaluated.
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
in 1998, and now operated by the Pierce County
Pierce County, Washington
right|thumb|[[Tacoma, Washington|Tacoma]] - Seat of Pierce CountyPierce County is the second most populous county in the U.S. state of Washington. Formed out of Thurston County on December 22, 1852, by the legislature of Oregon Territory...
Department of Emergency Management and several cities . It is supposed to assist in the evacuation of the Puyallup River Valley in Washington state
Washington State
Washington State may refer to:* Washington , often referred to as "Washington state" to differentiate it from Washington, D.C., the capital of the United States* Washington State University, a land-grant college in that state- See also :...
in the event of a volcanic eruption from Mt. Rainier.
History
Mount Rainier
Mount Rainier is a massive stratovolcano located southeast of Seattle in the state of Washington, United States. It is the most topographically prominent mountain in the contiguous United States and the Cascade Volcanic Arc, with a summit elevation of . Mt. Rainier is considered one of the most...
, an active volcano in Washington state
Washington State
Washington State may refer to:* Washington , often referred to as "Washington state" to differentiate it from Washington, D.C., the capital of the United States* Washington State University, a land-grant college in that state- See also :...
which last erupted in 1882, has occasionally buried sections of the Puyallup River valley in volcanic mudflow. Currently, more than 100,000 people live on the deposits of Mount Rainier lahar
Lahar
A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley. The term is a shortened version of "berlahar" which originated in the Javanese language of...
s that have occurred within the last 6,000 years.
Geologists consider Mount Rainier the most dangerous mountain in the United States,
and the Geological Survey has estimated there is a 1-in-7 chance of a catastrophic lahar at Mount Rainier occurring in the next 75 years.
University of Washington
University of Washington is a public research university, founded in 1861 in Seattle, Washington, United States. The UW is the largest university in the Northwest and the oldest public university on the West Coast. The university has three campuses, with its largest campus in the University...
, provides continuous monitoring of seismic activity in the area and is intended to provide first indication of volcanic unrest at Mount Rainier. However, while the PNSN is able to detect that a lahar-generating event has occurred, it is not able to determine the location or flow of debris. Beginning in 1998 a lahar-detection system consisting of five acoustic flow monitors was installed around Mount Rainier which would help identify the speed and direction of a lahar. Comprehensive coverage, which would require 30 to 40 such monitors, has yet to be installed.
Since 2000, the nascent lahar detection system has been operated by the Pierce County Department of Emergency Management which also has responsibility for coordination of public information and evacuation of areas of potential impact. Tacoma, at the mouth of the Puyallup, is only 37 miles (60 km) west of Mount Rainier, and moderately sized towns such as Puyallup
Puyallup, Washington
Puyallup, Washington is a city in Pierce County, Washington about five miles east of Tacoma. The population was 37,022 at the 2010 Census. Named after the Puyallup Tribe of Native Americans, Puyallup means "the generous people."-History:...
and Orting are only 27 and 20 miles (43 and 32 km) away, respectively.
Components
Current
Local governmental authorities would be notified of a lahar-generating event by staff at the Pacific Northwest Seismic Network. Confirmation and direction of the lahar would be received from information generated by acoustic flow monitors positioned around Mount Rainier and analyzed by a computer maintained by Pierce County, at which time a localized or general evacuation of the Puyallup River Valley could be ordered. It is estimated residents of areas that could potentially be effected by a lahar would have one hour or less to evacuate.The public alert component of the warning system is composed of a network of 26 siren
Civil defense siren
A civil defense siren is a mechanical or electronic device for generating sound to...
s owned by the municipalities in which they are located. The sirens are augmented by a Reverse 911
Reverse 911
Reverse 911 is a public safety communications system developed by Cassidian Communications, formerly PlantCML, a unit of EADS North America. It is used by public safety organizations in Canada and the United States to communicate with groups of people in a defined geographic area...
system maintained by the county and a dedicated emergency management radio station broadcasting at 1580AM. Directional signs in the area of potential impact are posted along pre-designated evacuation routes.
Planned
As of 2009 Pierce County was in the process of linking the county's warning sirens via satellite which would enable centralized activation of the alarms by county officials and mitigate the possibility that some might not sound in the event of a lahar, a problem encountered during tests. Plans to outfit 35 of the county's roadside evacuation signs with LEDLEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
's that could be illuminated during a volcanic event are also being evaluated.
Problems
- In semi-annual tests of the warning system, more than twenty percent of the sirens have periodically failed to sound the alarm tones. During a 2007 test, the dedicated emergency broadcaster - 1580AM - failed to switch automatically to the prerecorded warning message, forcing officials to switch the station's programming manually.
- During a 2006 test of the Emergency Alert SystemEmergency Alert SystemThe Emergency Alert System is a national warning system in the United States put into place on January 1, 1997, when it superseded the Emergency Broadcast System , which itself had superseded the CONELRAD System...
in Washington state, operator error resulted in the transmission of a volcano alert to broadcast stations. The alert, which was not corrected for 41 minutes, was carried over-the-air by KELA-AMKELA (AM)KELA is a radio station broadcasting a talk radio format, co-licensed to Centralia and Chehalis, Washington, USA. The station is currently owned by Bicoastal Media....
.
Cultural references
- An episode in the 2006 History Channel series Mega DisastersMega DisastersMega Disasters is an American documentary television series that originally aired from May 23, 2006 to July 2008 on The History Channel. Produced by Creative Differences, the program explores potential catastrophic threats to individual cities, countries, and the entire globe.The two...
, titled "American Volcano", was about the impacts of a catastrophic lahar resulting from the eruption of Mount Rainier. - An episode of It Could Happen TomorrowIt Could Happen TomorrowIt Could Happen Tomorrow is a television series that premiered on January 15, 2006 on The Weather Channel. It explores the possibilities of various weather and other natural phenomena severely damaging or destroying America's cities...
discusses what would happen if Mount Rainier erupted and caused a lahar.