Images

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

Series of daily sample bottles containing integrated water samples from the Elwha River, October 17, 2012 to November 9, 2012. Graphical overlay is the measured suspended sediment concentration in each sample bottle, showing the variability in sediment concentration during the time period shown.

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.

Series of daily sample bottles containing integrated water samples from the Elwha River, October 17, 2012 to November 9, 2012.

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.

Mount St. Helens and North Fork Toutle River Channel.

Antennas deployed in the Wind River to monitor movements of fish that have been tagged with Passive Integrated Transponder (PIT) tags.  The need to track fish movements in large streams over extensive areas has extended this current technology to new levels.

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.

Aerial photograph of the mouth of the Elwha River where it meets the Strait of Juan de Fuca during the removal of the Elwha and Glines Canyon dams, Washington State, USA. Aerial assistance by LightHawk and plane piloted by Dr. Hunter Handsfield.

Aerial photograph of the former Lake Aldwell reservoir and the Elwha River 16 months following the removal of the Elwha Dam, Washington State, USA. Aerial assistance by LightHawk and plane piloted by Dr. Hunter Handsfield.

Aerial photograph of the former Lake Aldwell reservoir and the Elwha River 16 months following the removal of the Elwha Dam, Washington State, USA. Aerial assistance by LightHawk and plane piloted by Dr. Hunter Handsfield.

Aerial photograph showing the mouth of the Elwha River, Washington State, USA. Aerial assistance by LightHawk and plane piloted by Dr. Hunter Handsfield.

Pale gills of a herring with VEN (top) compared to those of an uninfected, healthy herring (bottom).

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.

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

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.

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.

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.

Steaming continues on the 1980-1986 dome. View to the south and the east arm of Crater Glacier.