Mount Rainier is a volcano in the Cascade range in Washington. Mount Rainier could kill thousands the next time it erupts and cripple the economy. Some people in Washington say that the possibility of Mount Rainier eruption in the very near future is remote. The last eruption of Mount Rainier was 150 years ago.
Take a tour of Mount Rainier.
What are the dangers of Mount Rainier to people?
The dangers of Mount Rainier to people are ballistic projectiles, tephra, pyroclastic flows, volcanic gases, landslides, and glacial outburst floods.
Tephra is an eruption that typically produces plumes of hot volcanic rock particles with volcanic gases. The particles are carried downwind, and will fall and produce a deposit that covers a broad area. They are hot enough to start a fire were they land, and don't usually extend beyond ten kilometers ( six miles) from the vent. Clouds of fine tephra can block sunlight and are frequently are accompanied by lightning. Inhaling tephra can create or aggravate respiratory problems. Ten or more centimeters ( four inches) of tephra can cause a building to collapse. Thin tephra can ruin crops and wet tephra can cause power lines to short out. Fine tephra is abrasive and can damage mechanical devices and increase maintenance problems. The fall of tephra is generally less severe than other volcanic phenomena. The 1980's eruption of Mount St. Helens showed that even thin accumulation of tephra can disrupt social and economic activity.
Landslides are a mass of sliding rocks, snow and ice. A landslide swept down Mount Rainier about 5,600 years ago. The landslide transformed into a gigantic lahar. It raced down the wets and main forks of the White River. It then spilled into the Pudget Sound 50 km downstream. The event is known as the Osceola Mudflow.
Ballistic projectiles are particles thrown from vents on ballistic arcs. The maximum range for a ballistic projectile rarely exceeds 5 km (3 miles). Most projectiles are less than a meter (3 feet) across. The main danger of projectiles is direct impact.
Pyroclastic flows can destroy all structures . People and animals can sustain injuries to their eyes and lungs from acids, ammonia, and other compounds present in volcanic gases, and can be suffocated by denser and all living things by burial, direct impact of rocks, or incineration.
Volcanic gas is dissolved gases that are released during and between eruptive air. Gases such carbon dioxide, will accumulate in closed depressions. Metals and other susceptible materials can be severely corroded.
Glacial outburst floods result from a sudden release of stored within or at the base of glaciers. Outburst floods often pose a serious hazard in the river valleys on the volcano. The peak discharge of an outburst flood may be greater than that of an extreme meteorological flood. The effects of outbursts are rarely noticeable outside the boundaries of Mount Rainier Park.
Over all I don't think I would like to live near Mount Rainier during a major eruption.
Figure 3. Hazard zones for lahars, lava flows, and pyroclastic flows from Mount Rainier. The map shows areas that could be inundated if similar in size to those of the past occured today. Lahar hazard is not equal in all valleys. Puyallup Valley is the valley most susceptible to lahars caused by flank collapse. Risk to individual drainages will be refinied as scientists learn more about the volcano.