Lahars...
I'd get away from that volcano if I were you.
Mother Nature's Trump Card
So...What are Lahars?
Image Credit: https://volcanoes.usgs.gov/images/pglossary/lahar.php
Why should we worry?
The Very Muddy "Meat and Potatoes"
Where should we worry?
How do you know a Lahar is bad for you?
When and Where have Lahars happened?
1.) November 13th, 1985: Armero, Colombia. Earlier that day, for the first time in 69 years, the Nevado Del Ruiz volcano erupted. The eruption, however, was only the beginning. Heated Gas and rock moving down the mountain melted the glaciers that rested there, mixing with the water to form gigantic lahars that flowed down the mountain at 50-60 kilometers per hour. In all, the lahars spread out 74 kilometers from the mountain, killing around 23,000 people on the way.
2.) June 15th, 1991: Mount Pinatubo, Philippines. Mount Pinatubo had just erupted at the same time that a typhoon was going overhead. The resulting deluge and subsequent mixture of the stormwater with volcanic material lead to lahars that killed over 1,500 people and damaged several river systems to the point that they are so saturated with sediment that it will take them years to repair. Post-eruption lahars have displaced 50,000 people and buried 400 square kilometers of land through sediment deposition.
Lahars have also happened at Mt. St. Helens in 1980, the Santa Maria Volcano yearly, Galunggung in 1982, and Mount Ruapehu in 2007.
How do we save ourselves from certain muddy doom?
Image Credit: https://commons.wikimedia.org/wiki/File:3882jfDolores_Bacolor_Pampanga_River_Megadike_Roadsfvf_02.JPG
- Acoustic flow monitoring that detects the rumbling of the ground that lahars cause as they go by.
- Manned Watchtowers
- Radio Telemetry Rain Gauges that measure rainfall in areas susceptible to lahars so that scientists know whether or not to worry about the potential for lahars.
- Building a large dam/dike that stops the flow of the lahar.
Sources
http://volcanoes.usgs.gov/hazards/lahar/
https://en.wikipedia.org/wiki/Geohazard
https://en.wikipedia.org/wiki/Pyroclastic_rock
https://en.wikipedia.org/wiki/Slurry
https://en.wikipedia.org/wiki/Pyroclastic_flow
http://study.com/academy/lesson/volcanic-hazards-prevention-landslides-lahars-tsunamis.html