Recovery of lakes located in the blast zone of Mount St. Helens

Summary

Water transparency and plankton data suggest that by 1991 the lakes located in the blast zone of the 1980 eruption of Mount St. Helens were again similar to other alpine lakes in the Pacific Northwest region. Lakes near Mount St. Helens, including lakes to the south of the volcano and not affected by the eruption as well as the lakes in the blast zone of the 1980 eruption, contain higher concentrations of ions than other alpine lakes in the region. Several of the lakes near Mount St. Helens develop clinograde oxygen profiles during the summer.