Mount Rainier, located just under 70 miles from Seattle, is considered one of the most volcanically active parts of the country. According to Alex Iezzi, a research geophysicist with the US Geological Survey, the mountain is in a state of background activity, and experts closely monitor its daily movements.
The USGS Cascades Volcano Observatory tracks Mount Rainier using infrasound and seismic sensors, gas sensors, and GPS sensors. These tools detect cracks and movement from below as magma rises, changes in volcanic fumes, and ground deformation. This information allows researchers to predict potential eruptions, with Iezzi stating that a large eruption would likely be detectable months in advance.
A potential eruption could bring ash to Seattle, but lava flows or mudflows impacting the city are highly unlikely. However, cities like Puyallup and Orting closer to the foothills face serious hazards from lahars – destructive volcanic mudflows that can swallow everything in their path.
Lahars were a major threat during the 1980 Mount St. Helens eruption, causing widespread destruction and killing 200 people. To prepare for this risk, many foothill communities, including Orting and Puyallup, hold annual lahar evacuation drills, with over 45,000 participants in one recent event.
While lahars can occur without a volcanic eruption from a landslide, the USGS team concentrates its sensors on the southwest slopes of Mount Rainier to monitor drainage areas. Iezzi notes that wind patterns often direct ash eastward, while the lahar risk primarily affects the western slopes. With Mount Rainier showing no signs of eruption in 1,000 years, the USGS will continue to closely monitor the mountain’s activity.
Source: https://komonews.com/news/local/mount-rainier-volcano-washington-volcanoes-risk-eruptions-danger-risk-erupt-lahar-usgs-earthquake-cascades