New Mount St. Helens sensors will take its pulse

PORTLAND — Seventeen new sensors will be placed around the moving and shaking Mount St. Helens in the next few weeks, in hopes of giving scientists a better picture about what's going on under the surface — and perhaps, better enable them to forecast eruptions.

The sensors will be linked to a national network that detects the most subtle movement in the earth's crust.

The mountain began signaling its current nonstop eruption with hundreds of earthquakes two years ago Saturday.

"Knowing more about a volcano's underlying mechanisms eventually could lead to techniques for predicting when eruptions will occur," said Sarah Venator, a geologist and engineer with the Plate Boundary Observatory, which is installing the instruments.

Venator and other engineers with the national observatory finished drilling an 800-foot hole near the Windy Ridge viewpoint about three miles northeast of the crater. Today, they will lower a sensitive strain meter into the 6-inch-wide hole, to detect ground deformation at extraordinarily small levels.

An earthquake-detecting seismometer also will be placed in the hole, and a GPS station will detect ground movements at the surface.

Data from the instruments will be transmitted to the observatory's Boulder, Colo., headquarters where it will be accessible to all scientists.