Mount Rainier, a snow-covered peak in Washington state, USA, poses a significant threat to the surrounding community due to the potential danger of lahars, which are fast-moving streams of water and volcanic rock that originate from melting snow and ice during volcanic eruptions. Despite not having major eruptions in the past 1,000 years, the volcano worries American volcanologists more than others, including the Yellowstone super volcano. Scientists are concerned that the high elevation and snow and ice cover on Mount Rainier make it susceptible to lahars, which could flow quickly through valleys and drainage channels, affecting densely populated areas.
The U.S. Geological Survey (USGS) suggests that in the event of an eruption, any lava flows would likely remain within the boundaries of Mount Rainier National Park, while volcanic ash would be carried eastward by winds away from population centers. However, lahars remain a significant concern, as tens of thousands of people living in the potentially affected areas could be at risk if a major lahar were to occur. The deadliest lahar in recent history occurred in Colombia in 1985, killing over 23,000 people within minutes.
A 2022 study simulated two worst-case scenarios that painted a grim picture of the potential impact of a lahar from Mount Rainier. The study calculated the volume and speed of potential lahars, indicating that densely populated areas such as Orting, Washington state, could be at risk of devastation if a lahar were to occur. To mitigate the risk, the USGS has established a lahar detection system at Mount Rainier and conducted large-scale evacuation drills involving thousands of students from various school districts in Washington state.