One of the joys of living on the slopes of an active volcano is the possibility of a lahar - from Infogalactic:
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.
Lahars are extremely destructive: they can flow tens of metres per second (22 mph or more), be 140 metres (460 ft) deep, and destroy any structures in their path. Notable lahars include those at Mount Pinatubo and Nevado del Ruiz, the latter of which killed thousands of people.
The Bellingham County Council recently tried to pass some onerous legislation that would have affected our lives out in the country but a large number of concerned citizens showed up and the resolution was tabled. This does not mean that we do not need protection. The real need is for notification. It seems that Mt. Rainier is getting this.
From the Seattle Times:
Mount Rainier to get new digital-warning system for massive mudflows
After the deadly Oso landslide enveloped a neighborhood in 2014, scientists and emergency managers launched a review of how they detect massive mudflows on one of the world’s most dangerous volcanos: Mount Rainier.
“That event (Oso) moved about 8 million cubic meters of mass,” said Scott Heinze, deputy director of Pierce County’s emergency-management department. “The projection for a Mount Rainier lahar is between 250 to 500 million cubic meters of mass — exponentially greater.”
Pierce County Executive Pat McCarthy pushed for the review, which examined the functionality of the current warning system and also compared it to others around the globe, he said. The sensors, which were installed in the 1990s, monitor fast-moving gushes of mud and debris, or lahars.
Volcanic mudflows — formed by large landslides or suddenly melting snow and ice during eruptions — are considered the mountain’s greatest hazard.
A bit more:
Mount Rainier, which is more than a half-million years old, rumbles with volcanic mudflows every 500 to 1,000 years, Heinze said, adding: “We’re in the window.”
And more:
A computer system at the state emergency-operations center at Camp Murray monitors the lahar-detection sensors, which are in the Carbon and the Puyallup river valleys. If computers detect the rumbling of a lahar, that system alerts 24-hour emergency-monitoring and notification centers, which in turn activate a warning system, according to the USGS.
Good - Mt. Rainier has the greatest risk for a lahar. Mt. Baker does have some risk - there are gas vents on the south slopes which are changing the chemistry of the rock. If this slips, there would be a flow to the south - Baker Lake, Concrete, Highway 20.
Leave a comment