Images

USGS gas geochemists Christoph Kern (left) and Laura Clor (right) during the airborne gas survey of Mount Rainier.

Gas composition data is displayed in real time during gas flights. The tablet display shows measurements of CO₂ (blue line), SO₂ (red line) and H₂S (green line) that are collected every second.

Gas inlet window plate holding rear-facing gas inlet ports, a temperature/relative humidity sensor, and an upward looking UV telescope that is connected to a spectrometer by fiber optic cable.

Aerial view of the summit of Mount Rainier taken during the gas flight. The photo was taken looking south, and Rainier (14,411’) rises prominently above the cloud deck at about 8,000’. Mount St. Helens (8,357’) is faintly visible in the distance.  

Depth of earthquakes during the July 8 - August 25, 2025, seismic swarm at Mount Rainier, WA.

Seismicity beneath Mount Rainier, Washington, showing earthquakes during 2020-2025 in blue, and those that occurred as part of an earthquake swarm on July 8 - August 25, 2025, in orange.

Plots of earthquake magnitudes (top) and numbers (bottom) over the course of the July 8 - August 25, 2025 seismic swarm at Mount Rainier, Washington.  The swarm was greatest in terms of numbers of events on the morning of July 8.  After that time, earthquake rates slowly decreased over the course of the following days.

During the March 21, 2024 lahar evacuation drills, thousands of students walked to the Washington State Fairgrounds in Puyallup, Washington to practice evacuating from a lahar generated by Mount Rainier. A lahar, or volcanic mudflow, could reach this area in about 3 hours.

Mount Rainier (Washington) volcano hazard zones and estimated lahar (volcanic mudflow) arrival times for the Puyallup and Nisqually River valleys.

Close-up oblique views of Mount Rainier’s west side showing simulated lahar flow depths from a landslide originating in the area of the Tahoma Glacier Headwall (T-260-HM simulation). Imagery appears blurry where lahar material is absent because D-Claw’s adaptive mesh refinement (AMR) employs very coarse resolution in those areas.

A seismologist with the Cascades Volcano Observatory checks the data output on a newly installed monitoring station at Mount Rainier.

Seismic and infrasound station PARA, installed October 6-8, 2020 at Mount Rainier.

A geophysicist from the Cascades Volcano Observatory notes the location of a newly buried seismometer at station PARA, on Mount Rainier.

NAGT intern Emily Bryant installs one of three infrasound sensors at volcano monitoring station PARA, at Mount Rainier.

Lahar monitoring equipment is housed in a secure box with multiple types of instruments to detect approaching lahars.  

USGS-Cascades Volcano Observatory geophysicist Rebecca Kramer works on station PR05, which is part of the Mount Rainier lahar detection network (Mount Rainier is pictured in the distance). The purpose of the site visit was to upgrade the power system and deploy infrasound equipment. 

Earthquakes at Mount Rainier from 2010 to 2019. As shown in the graphic, fluids from the magmatic system beneath the volcano rise through existing cracks and weaknesses in the crust. Along with rainwater and ice/snow melt, these fluids combine to create a hydrothermal system within the volcano.

Top: Map view of well recorded historical seismicity at Mount Rainier since 2007 (gray circles) with seismicity since September 11 plotted as filled red circles. Location of seismic stations indicated by arrows. Bottom: Cross-sectional view looking north shows earthquake depths. Black outline is a west-east elevation profile of Mount Rainier.

The east side of Mount Rainier, as viewed from Panhandle Gap.

LaharZ model (left) of the possible lahar hazards from the Carbon and Puyallup River drainages from Mount Rainier. The town of Orting, Washington (photograph) sits in the lahar hazard zone.

This map shows areas that could be affected by debris flows, lahars, lava flows, and pyroclastic flows from Mount Rainier if events similar in size to past events occurred today. Because small lahars are more common than large ones, most lahars would be less extensive than the hazard zone shown on the map and a few would be more extensive.