| The 1980 eruption of Mount St. Helens, Washington, afforded an opportunity to study its physical, chemical, and biological effects on lakes near the volcano and to describe two newly created lakes. From June 1980 to August 1982, water samples were collected from four lakes in the blast zone and two outside the blast zone, as well as from the two newly created lakes. Concentrations of chemical constituents were inversely related to the distance of a lake from the volcano. Dissolved solids and total organic carbon, measured in June 1980, had increased from 2 to 30 times the concentrations observed in the 1970's in Spirit, St. Helens, and Venus Lakes. Major-ion composition and the water types of the study lakes except Walupt Lake were altered from preeruption calcium-bicarbonate types to calcium-sulfate, calcium-sulfate-chloride, or mixed type. -- Embrey and Dion, 1987 |
![Map [32K,GIF]: Lakes North of Mount St. Helens Affected by the May 18, 1980 Eruption](https://webharvest.gov/peth04/20041031144025/http://vulcan.wr.usgs.gov/Imgs/Gif/MSH/Maps/map_may18_affected_lakes.gif){kind=link}