Images

A lahar is a volcanic mudflow. Learn if you are if you are in a lahar hazard zone and how to evacuate to high ground. If you are in a lahar hazard zone and get a lahar alert - go now! Every second matters. 

A shaded relief map of Mount Rainier with GPS track from the gas observation flight. The colors correspond to CO₂ levels in parts per million by volume (ppmv) that were measured during the flight. Yellow points indicate elevated CO₂ levels, which were located near visibly degassing volcanic gas vents.

Gas sensor packages mounted to the floor of the aircraft near the rear passenger seats, connected to the outside through black tubing that attaches to the window plate, pictured above.

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

View from the helicopter cabin showing the connections from the inlet window to the measurement equipment inside.

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.  

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.

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.

Roughly a third of the total erupted volume of the Clear Lake volcanic field is represented by the ~ 35 km³ of rocks comprising Mt. Konocti and nearby hills. The mountain itself is over 1200 m (~4000 ft) high and is comprised primarily of a series of dacitic lava domes – Buckingham Peak, Wright Peak, and South Peak, and Howard Peak are all dacites.

The top of Bare Mountain (foreground) looking towards the southwest. Bare Mountain has two components: a pre-glacial (older than about 20,000 years) andesite lava flow that travelled to the north, after which the top of the eruptive vent was destroyed in an explosive eruption that formed a 475 meter (1550 feet) wide and 145 meter (475 feet) deep crater.

A basalt of Sister Rocks dike (a subsurface magmatic structure) cutting across a scoria deposit from a previous eruption of Sister Rocks. Being in a scoria deposit can indicate that you are near a volcanic vent, as scoria is not ejected very far from its source. This feature can be accessed just off the trail to the summit of Sister Rocks.

Talus slopes of the basalt of Soda Peaks (foreground), the oldest known eruption in the West Crater area, overlooking the andesite of West Crater (middle background), the youngest known eruption. This area is heavily vegetated and steeply sloped, which provide a challenge for rock sampling. Photo by James Genero, CVO summer intern, June 2025.

These bathymetric maps, created with data from NOAA's National Centers for Environmental Information (NCEI), show the Juan de Fuca Ridge offshore of the Pacific Northwest of the United States.

Map of Newberry volcano shows location where earthquakes occurred during geothermal work in 2012 and 2014 (orange circles) and volcanic earthquakes that have occurred since 2011 (blue circles).

Research Scientist Emily Johnson calibrates the FTIR in the Cascades Volcano Observatory Petrology Lab.

Research Scientist Emily Johnson calibrates the FTIR in the Cascades VOlcano Observatory Petrology Lab.

Screenshot of an algorithm that David George is working on to model debris flows.

A screenshot of an algorithm that David George is working on at CVO. David uses math and computer programming to solve complex problems.