Images

A survey base station is established using a RTK-GPS receiver with mobile units to collect data points in and around the crater. Information will be used to monitor surface changes, deformation, erosion and aggradation inside the crater. This type of technology is precise to the centimeter. View to the south, toward Crater Glacier and the lava domes.

Fieldwork includes direct observations of changes to streams and stream beds to determine how changes will affect the downstream transportation of sediments. Here, the braided North Fork Toutle (left) joins Carbonate Springs Creek (right). View to the east.

Monitoring stations need to be portable. Weighing about 500 pounds, this "swing set" structure can be airlifted into place or moved, as volcano monitoring needs change. An additional 1,000 pounds of equipment will need to be added to make the station fully functional.

Center for the Study of Active Volcanoes (CSAV) students Javier Pacheco (Costa Rica) and Syegi Kunrat (Indonesia) participate in field studies at Mount St. Helens.

Teachers take a guided walk on the Hummocks Trail, learning about the depositional features of the May 18, 1980 eruption.

Todd Cullings, with the Mount St. Helens National Volcanic Monument, leads teachers in activities they can do with students before hiking the Hummocks Trail.

The September Lobe monitoring station is part of the network of monitoring stations that detects and reports subtle changes in the volcanic vent area. At 2150 m (about 7100 ft) elevation, maintenance is performed during good weather to keep the station fully functional.

To monitor volcanoes, scientists rely on remote monitoring equipment that can operate 24-hours a day and 365-days a year to deliver real-time data. When scientists design and install monitoring stations, they must consider the remoteness of sites, terrain, and winter conditions. Here, rime ice coats a telemetry system that transmits data near Mount St.

Lakes and drainages within the watershed of Mount St. Helens.

Mount St. Helens and the industrial waterfront area of North Portland, Oregon along the Willamette River in the foreground. Excess sediment from volcanoes can significantly impact river traffic.

Logs float in Spirit Lake near the Spirit Lake gaging station and outflow tunnel. View is to the south with Mount St. Helens in the background.

The May 18, 1980 eruption of Mount St. Helens had a dramatic impact on the North Fork Toutle River. The debris avalanche, lateral blast and ashfall produced a substantial amount of sediment, which continues to be washed into the river and transported downstream.

The USGS, in collaboration with UNAVCO and the University of Colorado, uses these data to measure channel erosion and deposition in the reach.

Back at the USGS Cascades Volcano Observatory office, these data are merged with airborne LiDAR data to calculate lake volume.

Volcano monitoring stations must be designed to withstand harsh winter conditions.

Stream channel cross-section measurements—instrument that uses laser pulses to survey distance to a reflector operated by a second crew member, Mount St. Helens.

Gas sampling with a CO2 Infrared Spectrometer at Mount St. Helens' September Lobe lava dome, Washington.

View of Mt. St. Helens at sunset, taken sometime after the crater forming eruption in 1980.

Suspended sediment sample collection from the North Fork Toutle River above the Sediment Retention Structure, downstream from Mount St. Helens.

Mount St. Helens, as viewed from Coldwater Ridge around sunset.

Seismic station VALT in Mount St. Helens crater, view toward the south.