Spirit Lake (Washington)

Infobox_lake
lake_name = Spirit Lake
location = North of Mount St. Helens
image_lake = Rainier05 mount rainier from st helens crater 02-03-05 med.jpg
caption_lake = (February 2005)
image_bathymetry =
caption_bathymetry =
coords = coord|46|16|38.8|N|122|7|55.53|W|type:city_region:US-WA|display=inline,title
type =
inflow = precipitation, streams
outflow = drainage tunnel
catchment =
basin_countries = United States
length =
width =
area =
depth =
max-depth =
volume =
residence_time =
shore =
elevation = Convert|3408|ft|m|0 (Convert|3198|ft|m|0|abbr=on|abbr=on before May 18, 1980)
islands =
cities =

Spirit Lake is a lake north of Mount St. Helens in Washington State. The lake was a popular tourist destination for many years until the 1980 eruption of Mount St. Helens. Thousands of trees were torn from the surrounding hillside after the lake was sloshed 800 feet up the hillside. Lahar and pyroclastic flow deposits from the eruption blocked the North Fork Toutle River valley at its outlet, raising the surface elevation of the lake by over Convert|200|ft|m|-1|abbr=on. The newly raised lake was also 10 percent smaller and much shallower.

After the eruption, Spirit Lake contained highly toxic water with volcanic gases seeping up from the lake bed. A month after the eruption, the lake was devoid of oxygen. Scientists predicted that the lake would not recover quickly,Fact|date=May 2008 but, perhaps surprisingly, three years after the Mount St. Helens eruption, Spirit Lake had more biological activity than ever before. In 1993, fish were seen for the first time in Spirit Lake since the 1980 eruption.Fact|date=May 2008

However, the logs that were deposited in the lake during the Mount St. Helens eruption still remain and cover a large portion of the surface water. The rasping of logs together has deposited tree bark in the bottom of the lake. The bare logs sink upright to the bottom of the lake due to the higher density of the root end, and land on layers of volcanic ash sediment. The high mineral content of the water rapidly petrifies the logs in upright position as transplanted stumps. Spirit Lake is the first location where this process was observed since being predicted by scientists shortly before the 1980 eruption. Even though the lake was devastated by Mount St. Helens, it has rebounded significantly and is on the way to recovery.

Before the eruption of Mount St. Helens, there were four camps on the shore of Spirit Lake: a Boy Scout camp, a Girl Scout camp, a YMCA camp, and another for the general public. There were also a number of lodges catering to visitors, including Spirit Lake Lodge and Mt. St. Helens Lodge; the latter was inhabited by Harry R. Truman, who became one of the volcano's victims.

References

* [http://vulcan.wr.usgs.gov/Volcanoes/MSH/Hydrology/Lakes/SpiritLake/framework.html USGS Cascades Volcano Observatory: Spirit Lake]