Unified Interior Regions

Washington

Washington's Puget Sound is a complex ecosystem directly adjacent to a robust metropolitan area that scientists from the USGS Western Fisheries Research Center study. Recent surveys have looked at juvenile surf smelt, a key link in the food web that are consumed by predators such as salmon, orca, and many marine birds. 

Western Fisheries Research Center

Western Fisheries Research Center

Research at the WFRC focuses on the environmental factors responsible for the creation, maintenance, and regulation of fish populations including their interactions in aquatic communities and ecosystems. 

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Washington Water Science Center

Washington Water Science Center

The Water Science Center's mission is to collect, analyze and disseminate the impartial hydrologic data and information needed to wisely manage water resources for the people of the United States and the State of Washington.

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States L2 Landing Page Tabs

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Deformation measurements on the Mount St. Helens' dome; three geolo...
April 18, 1988

Deformation measurements on the Mount St. Helens' dome; three geolo...

Deformation measurements on the Mount St. Helens' dome; three geologists in middle bottom of this aerial photograph.

Dome building eruption at Mount St. Helens—30-minute, moon-lit expo...
October 22, 1986

Dome building eruption at Mount St. Helens—30-minute, moon-lit expo...

The last dome-building eruption of Mount St. Helens during the 1980s occurred in October 1986. A new lobe was extruded, increasing the dome's height to 925 feet (282 meters), making it taller than a 77-story building. In volume, the dome was nearly 40 times the size of Seattle's Kingdome stadium. The view is from Harry's Ridge, five miles (8 kilometers) north of the

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View of the Spirit Lake outlet tunnel, built in 1985, that allows w...
October 2, 1986

View of the Spirit Lake outlet tunnel, built in 1985, that allows w...

View of the Spirit Lake outlet tunnel, built in 1985, that allows water to drain out of Spirit Lake safely and maintain the lake's water level 100 ft (30 m) below the estimated overtopping level.

Lava dome in Mount St. Helens' crater as viewed from the "Deepthroa...
August 12, 1985

Lava dome in Mount St. Helens' crater as viewed from the "Deepthroa...

The lava dome was taller than a 66-story building and almost as wide as the length of nine football fields. The dome completely fills the camera's field of view. Compare with image taken August 22, 1981 from the same location with the same camera.

Mount St. Helens four years after the May 18, 1980 eruption—lava do...
September 24, 1984

Mount St. Helens four years after the May 18, 1980 eruption—lava do...

Mount St. Helens four years after the May 18, 1980 eruption—lava dome in the crater and drainage channels development on flanks; view from Johnston Ridge.

Fireweed, growing in Mount St. Helens' devastated area; view from t...
August 15, 1984

Fireweed, growing in Mount St. Helens' devastated area, Summer 1985

Vegetation began reappearing as early as the summer of 1980 as many small trees and plants were protected by the snowpack on May 18. Seeds, carried by the wind or by animals, also entered the area and grew. By 1985, the ridges surrounding the volcano were covered with new growth.

Measurements of the magnetic field surrounding the Mount St. Helens...
June 18, 1984

Measurements of magnetic field surrounding the Mount St. Helens' dome

The strength of the magnetic field increased as the dome cooled and magnetic minerals formed. During the eruptions the strength usually changed rapidly as magma heated and deformed the dome.

Castle Lake formed as a result of the Mount St. Helens' May 18, 198...
March 15, 1984

Castle Lake formed as a result of the Mount St. Helens' May 18, 198...

The May 18, 1980 debris avalanche from Mount St. Helens covered over 24 square miles (62 square kilometers) of the upper Toutle River valley and blocked tributaries of the North Fork Toutle River. New lakes such as Castle Lake (pictured here) and Coldwater Lake were created.

Debris avalanche deposit with hummocky terrain resulting from the M...
January 13, 1984

Debris avalanche deposit with hummocky terrain resulting from the M...

Debris avalanche deposit with hummocky terrain resulting from the May 18, 1980 eruption of Mount St. Helens. View to the east toward Coldwater Lake.

Dome in Mount St. Helens crater; two USGS geologists (one in orange...
May 26, 1983

Dome in Mount St. Helens crater; two USGS geologists (one in orange...

By 1987, the dome had replaced only three percent of the volume removed by the May 18, 1980 eruption. If that rate of growth had continued it would have taken over 200 years to rebuild Mount St. Helens to its pre-1980 size. Instead, Mount St. Helens entered a quiet period which continued until 2004.

Early Warning Gage on Coldwater Lake at Mount St. Helens continuous...
October 1, 1982

Early Warning Gage on Coldwater Lake at Mount St. Helens continuous...

One major concern to people living downstream of Mount St. Helens was a breakout of any of the impounded lakes, such as Coldwater or Castle Lakes, due to the instability of the debris dams blocking them. Flood waters from a breakout could be more catastrophic than the lahars of May 18, 1980. Gages, such as this Early Warning Gage on Coldwater Lake, were installed at lakes

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Western Fisheries Research Center

Western Fisheries Research Center

Research at the WFRC focuses on the environmental factors responsible for the creation, maintenance, and regulation of fish populations including their interactions in aquatic communities and ecosystems. 

Go to Center

Washington Water Science Center

Washington Water Science Center

The Water Science Center's mission is to collect, analyze and disseminate the impartial hydrologic data and information needed to wisely manage water resources for the people of the United States and the State of Washington.

Go to Center