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In-stream distribution and hydraulic and ecological effects of volcanic ash from Mount St. Helens eruption. Technical completion report, grant no. 14-34-0001-1466 Item Info

The catastrophic eruption of Mt. St. Helens in southwestern Washington on May 18, 1980 deposited a plume of volcanic ash from Washington to western Montana. Ash deposits in northern Idaho were significant with depths varying from 2 to 3 mm in the fringes to as much as 50 mm in the central area of the plume as it crossed the Idaho panhandle. Varying amounts of the ash were deposited directly in streams located in the plume area. This study is an evaluation of the changes in the in-stream ecological conditions resulting from volcanic ash deposition and transport. This interdisciplinary evaluation of the in-stream effects of the new volcanic ash deposition in the physical and biotic components of streams in the ashfall plume area was studied by recreating, on a simulated basis, condition prior to, during, and after the ash deposition, and by field verification measurements taken in the Palouse River to support the simulation studies. The results obtained from the simulation and field studies clearly indicate catastrophic influences of volcanic ash deposition and transport on attached benthic algae biomass and on the dislocation of invertebrates and interruption of food-chain relationships. While the short-term impact was moderate to severe on selected populations, all of the principal species tested demonstrated considerable persistence and resilience such that long-term effects of the ash on the in-stream ecosystem are judged to be minimal.

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Title:
In-stream distribution and hydraulic and ecological effects of volcanic ash from Mount St. Helens eruption. Technical completion report, grant no. 14-34-0001-1466
Authors:
Milligan, James M.; Falter, C. Michael; Brusven, Merlyn A.
Date Created (ISO Standard):
1983-10
Description:
The catastrophic eruption of Mt. St. Helens in southwestern Washington on May 18, 1980 deposited a plume of volcanic ash from Washington to western Montana. Ash deposits in northern Idaho were significant with depths varying from 2 to 3 mm in the fringes to as much as 50 mm in the central area of the plume as it crossed the Idaho panhandle. Varying amounts of the ash were deposited directly in streams located in the plume area. This study is an evaluation of the changes in the in-stream ecological conditions resulting from volcanic ash deposition and transport. This interdisciplinary evaluation of the in-stream effects of the new volcanic ash deposition in the physical and biotic components of streams in the ashfall plume area was studied by recreating, on a simulated basis, condition prior to, during, and after the ash deposition, and by field verification measurements taken in the Palouse River to support the simulation studies. The results obtained from the simulation and field studies clearly indicate catastrophic influences of volcanic ash deposition and transport on attached benthic algae biomass and on the dislocation of invertebrates and interruption of food-chain relationships. While the short-term impact was moderate to severe on selected populations, all of the principal species tested demonstrated considerable persistence and resilience such that long-term effects of the ash on the in-stream ecosystem are judged to be minimal.
Subjects:
Volcanoes volcanic ash Deposition Benthic environment Food chains
Location:
Northern Idaho; Palouse River
Latitude:
46.89
Longitude:
-117.37
Collection:
Palouse Basin
IWRRI number:
198316
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
Publisher:
Idaho Water and Energy Resources Research Institute; University of Idaho
Contributing Institution:
University of Idaho
Type:
Text
Format:
application/pdf
Cataloger:
KIT
Date Digitized:
2017-08-28

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Preferred Citation:
"In-stream distribution and hydraulic and ecological effects of volcanic ash from Mount St. Helens eruption. Technical completion report, grant no. 14-34-0001-1466", Idaho Waters Digital Library, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/iwdl/items/iwdl-198316.html
Rights
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
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