Pacific Northwest Research Station

Title: 25 years of ecological change at Mount St. Helens.

Author: Dale, V.H.; Crisafulli, C.M.; Swanson, F.J.

Date: 2005

Source: Science, Vol. 308: 961-962

Description: 18 May 2005 marks the 25th anniversary of the massive eruption of Mount St. Helens. This eruption involved diverse geological processes (1) that disturbed forests, meadows, lakes, an drivers (2) (see the figure). A huge landslide and searing flows of hot gases and pumic framents (pyroclastic flows) inundated 60 km² of land, obliterating preexisting ecosystems and landforms. A steam-driven blast left blown-down forest and scorched standing forest over more than 500 km², but deposited generally <1 m of new material. A gentle rain of tephra (airborne volcanic rock fragments) fell from the sky and blanketed >1000 km² of live forest and aquatic systems with >5 cm of deposits (2). The initial impression of a lifeless landscape quickly changed as surviving plants and animals reemerged.

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Citation

Dale, V.H.; Crisafulli, C.M.; Swanson, F.J.  2005.  25 years of ecological change at Mount St. Helens..   Science, Vol. 308: 961-962.