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Surveying stream channels at Mount St. Helens...
January 17, 2014

Surveying stream channels at Mount St. Helens

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

Monitoring river discharge near Mount St. Helens, Washington....
October 30, 2013

Monitoring river discharge near Mount St. Helens, WA.

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.

Maintenance at Acoustic Flow Monitor near Mount St. Helens, Washing...
October 18, 2013

Maintenance at Acoustic Flow Monitor near Mount St. Helens, WA

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.

SWFL seismic station, on the crater rim of Mount St. Helens, was re...
August 7, 2013

SWFL seismic station, on the crater rim of Mount St. Helens, was re...

This summer, crews made significant modifications to a monitoring station on the southwest flank of Mount St. Helens, greatly improving its operability in winter. Volcano monitoring stations are designed to integrate many instruments into a single package to lower power requirements, reduce instrument footprint on sensitive landscapes, be portable for rapid deployment and

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Annual surveys of water channels in the crater of Mount St. Helens ...
August 7, 2013

Annual surveys of water channels in the crater of Mount St. Helens ...

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.

Helicopter gives SWFL "swing set" a lift, Mount St. Helens....
August 6, 2013

Helicopter gives SWFL "swing set" a lift, Mount St. Helens.

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.

Touchdown at monitoring site in Mount St. Helens' crater....
August 6, 2013

Touchdown at monitoring site in Mount St. Helens' crater.

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.

Precise surveying of Mount St. Helens crater with RTK-GPS technolog...
August 6, 2013

Precise surveying of Mount St. Helens crater with RTK-GPS technology.

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.

Erosional channels lead away from the northern face of Crater Glaci...
August 6, 2013

Erosional channels lead away from Crater Glacier, Mount St. Helens

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. Pictured at the center bottom of the image are newly carved (over the last two years) seasonal channels 2-4 m (6-13 ft) deep that funnel water to the

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The sound of summer: rockfall inside the crater of Mount St. Helen...
August 6, 2013

The sound of summer: rockfall inside the crater of Mount St. Helens.

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.