Mount Rainier

Mount Rainier is a large active stratovolcano located in Washington, USA that began to grow 500,000 years ago above the remains of a previously active Mount Rainier. Mount Rainier is the highest volcano in the Cascade Range at 4392 meters (14,410 ft) above sea level with indications that in past it may have been 305 meters (1000 ft) higher. The loss of height is due to the eruption history and landslides. The most recent eruption from Mount Rainier is from 1894-95 and was a small summit eruption.

Mount Rainier is located in Washington, USA in close proximity to human population. If Rainier were to erupt it would affect "3.3 million in the Seattle Tacoma metropolitan area, and its drainage system via the Columbia River potentially impacts another 500,000 residents of southwestern Washington and northwestern Oregon" (National Park Service). Mount Rainier due to its close proximity to people, and having large glaciers and snow accumulation, is known as the most dangerous volcano in the Cascade region and one of the most dangerous in the United States.

There are currently 25 glaciers that are on Mount Rainier and contain more than "five times as much snow and ice as all the other Cascade volcanoes combined" (USGS). Mount Rainier has a large potential for lahars due to the excessive water and can happen with or without an eruption. "Lahars and debris flows look and behave like flowing concrete, and they destroy or bury most manmade structures in their paths" (USGS). This would cause massive damage to the Puget Sound Lowland which includes Seattle, Tacoma, Everett, Olympia, and Bremerton. Scientists believe that a lahar would be able to travel from Mount Rainier to the Puget Sound Lowland within 30 minuets. This area is highly populated with a population of about 100,000 people. This area has had history of being covered by at least 9 large lahars in the past 5,600 years that reached the Puget Sound Lowland.

If Mount Rainier were to erupt there are other potential hazards that could cause damage to the environment and impact human life.

These hazards include:

• Ash
• Lava flows
• Hot rock
• Debris flow
• Pyroclastic Flow
• Floods
• Water quality would be affected.
• Air quality would be affected.
• Ash would stop all flying in the area.
• Food shortage in surrounding areas.
• Power outages would occur.
• Increased atmospheric temperatures.

If Mount Rainier were to erupt today, we would first see steam and ash.

This would then transition into a lava flow, and pyroclastic flow.

Avalanches could begin before or without any eruption due to earthquakes dislodging loose material affecting homes close to Mount Rainier.

• Today Mount Rainier is heavily studied to be able to detect a possible eruptions debris flows and lahars. The USGS, the Pierce County Department of Emergency Management, and Washington State Emergency Management Division have teamed up to monitor Mount Rainier for possible lahars. This monitoring is meant to get a warning out to the public to have minimal loss of life in the areas that would be affected by a lahar. These agencies began this effort in 1995. Monitors have been set in place to detect the ground shaking of lahars and get warning out to the public.
• Volcanic activity is monitored through:
  • seismicity- increase in seismicity indicates it is becoming more active
  • volcanic gases- shows the type of eruption that may occur
  • ground deformation- indicates movement of magma in the volcano
  • hydrothermal activity- change in activity may indicate possible activity

• Water Quality- Water quality is managed under the Federal Water Pollution Control Act Amendments of 1972, and the Clean Water Act of 1977
• Air quality- Protected under Clean Air Act
• Climate Change
• Fires

Mount Rainier is an active volcano located in Washington, USA that is the most dangerous volcano in the Cascade Range. The primary threat associated with living in close proximity to Mount Rainier is the potential for lahars, presenting a significant risk to numerous cities within the danger zone. What adds to the situation is that lahars can occur without a volcanic eruption, triggered by slope instability, and melting snow/ice. The lack of warning leaves residents vulnerable, heightening the potential for loss of life as there may be insufficient time to evacuate from the danger zones.