Measurements of the Stratospheric Plume from the Mount St. Helens Eruption: Radioactivity and Chemical Composition
R. LEIFER 1,
L. HINCHLIFFE 1,
I. FISENNE 1,
H. FRANKLIN 1,
E. KNUTSON 1,
M. OLDEN 1,
W. SEDLACEK 2,
E. MROZ 2, and
T. CAHILL 3
1 Environmental Measurements Laboratory, Department of Energy, New York 10014
2 Los Alamos National Laboratory, Los Alamos, New Mexico
3 Crocker Nuclear Laboratory, University of California, Davis 95616
Gas measurements made in the stratospheric plume from the eruption of Mount St. Helens on 18 May 1980 were not consistent with a reported large injection of radon-222 into the atmosphere. No enrichment in the volatile element polonium was found in filter samples, and the ratio of polonium-210 to lead-210 was not different from background values. Data obtained with an experimental impactor, flown shortly after the eruption, showed an increase of 103 in the stratospheric number concentration of submicrometer sulfate particles compared to concentrations before the eruption.
Submitted on April 27, 1981
Revised on July 15, 1981
