Overview
- The seismic swarm began at 1:29 a.m. local time on July 8 and encompassed hundreds of quakes up to magnitude 1.7 at depths of 2–6 km beneath the summit
- The USGS Cascades Volcano Observatory and Pacific Northwest Seismic Network have intensified monitoring with seismic sensors, infrasound arrays, GPS stations and webcams
- Observations reveal no detectable magma movement, surface deformation, infrasound anomalies or changes in volcanic gas emissions
- Mount Rainier’s volcano alert level and aviation color code remain at green, indicating no increased threat of eruption
- The volcano is designated as Very High Threat under the National Volcano Early Warning System due to its glacial cover and proximity to populated areas vulnerable to lahars