Spirit Lake (Washington)

The Spirit Lake is a lake on the north flank of Mount St. Helens in Skamania County, Washington. He was replenished after the eruption of the volcano on 18 May 1980 volcanic material and shifted its height to 60 m upwards. The small lake was for many years covered on the surface of tree trunks that were swept along with a pyroclastic flow into the lake. Parts thereof swim even after almost 30 years.

The increased water level was seen as a threat, because at a fraction of bank structures the mass of water would be discharged into a catastrophic flood event. Therefore, the United States Army Corps of Engineers drilled through May 1985 for both tunnel as Wasserab and overflow from the lake in the Coldwater Creek, which flows through the North Fork Toutle Toutle and the Cowlitz River in the River.

In the eruption of Mount St. Helens a complete edge of the hill was removed, the material fell to the valley and gathered in the small lake. The entry of sulfur and other minerals led to an acidification of the lake. The degradation of the incorporated biomass of the oxygen was consumed in the water, so that the lake fell over. Contrary to expectations, the scientists, the regeneration but not lasted several decades; the oxygen cycle had come back on track after the rainfall and temperature cycles of two winters.

The Spirit Lake is located in the priority area for ecological research in the Mount St. Helens National Volcanic Monument, and it is marked trails. On the hills of Windy Ridge in the east of the conservation area is a viewpoint above the lake which can be reached via a forest road. From there, a proven, a short but steep walk to the only permitted point on the shore of the lake.