Images

USGS-CVO Research Geologist Peter Kelly communicates with the helicopter pilot and prepares for pick-up, on the new dome within the crater of Mount St. Helens.

USGS researcher Jeff Wynn monitors in-coming data at the CSAMT (Controlled-Source Audio-Magnetotellurics ) receiver site on Mount St. Helens. The data will be used to locate the top of the groundwater system beneath the site.

The new volcanic-gas monitoring station installed at Mount St. Helens consists of weather monitoring equipment and sensors for measuring the concentrations of water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), and hydrogen sulfide (H2S) in volcanic gas plumes.

Mauve indicates areas at risk from lava flows and avalanches of hot rock and gases called pyroclastic flows. Bright red areas that fade to orange and yellow indicate potential routes for lahars (volcanic mudflows). Not shown are areas subject to hazards from volcanic ash.

A photograph of Mount St. Helens, as viewed from Elk Rock on January 18, 2014.

Scientists conduct a stream channel cross-section survey of the Toutle River on the north side of Mount St. Helens (view to the southwest).

Map showing one-year probability of accumulation of 1 centimeter (0.4 inch) or more of tephra from eruptions of volcanoes in the Cascade Range.

Map of Mount St. Helens Crater Glacier created from LiDAR data acquired September 2009.

This shaded relief image was produced from LIDAR data. LIDAR is an acronym for Light Detection and Ranging, a modern remote sensing technique used to map topography very accurately—more so than is possible with older techniques. The crater is 1.2 miles (1.9 km) wide east-west. Elsewhere the scale varies owing to the oblique viewing angle.

Mount St. Helens and North Fork Toutle River Channel.

Crews test two methods of measuring discharge of the Muddy River near Mount St. Helens, Washington. The computer and tethered orange float create a vertical discharge profile; the hand-held flow tracker confirms the data. Data collection is becoming more electronic-oriented with periodic confirmation of results by physical observations.

Repairs are made to an Acoustic Flow Monitor (AFM) located at the confluence of the North Fork Toutle River, Maratta, Castle and Coldwater Creeks, where the most recent lahar occurred in November, 2006. AFMs are installed to "hear" when lahars [muddy debris flows] move down channel so affected communities can be warned of the hazard.

This summer, crews made significant modifications to a monitoring station on the southwest flank of Mount St. Helens, greatly improving its operability in winter.

Crews survey Loowit Creek channel and other points inside the crater. Elevation information is used to make a longitudinal profile of the channel, characterizing areas where sediment is either deposited or transported and how the channel is changing with time. View to the north, with Spirit Lake and Mount Rainier in the background.

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 is to the south of Mount St.

Monitoring and upgrading ground-based sensor networks at the most active volcano in the Cascades is an on-going process. Crews made significant modifications to a seismic monitoring station on the southwest flank of Mount St. Helens, greatly improving its operability in winter.

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.

Crews access remote monitoring sites by helicopter. Pictured out the window of the helicopter is a GPS and camera station, dedicated to remotely monitoring changes inside the crater and under the crater floor.

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.

Crater Glacier, located inside the crater of Mount St. Helens, continues to move at an average rate of about 11 cm per day (4.3 inches). During warm weather months, meltwater creates erosional channels on the crater floor.

In summer, the crater of Mount St. Helens is filled with a near constant sound of rockfall from the steep 600 m high (about 2000 feet) crater walls. The falling rock kicks up ash and dust (pulverized rock) as it tumbles onto the crater floor. View of east crater wall.