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GOES weather satellite observations and measurements of the May 18, 1980, Mount St. Helens eruptionWe demonstrate the use of Geostationary Operational Environmental Satellite (GOES) images of the May 18, 1980, Mount St. Helens volcanic plume in providing details of the dynamics and changing character of this major explosive eruption. Visible and thermal infrared (IR) data from a sequence of images at 30-min intervals from 0850 to 1720 Local Time (LT) give information on dispersal and plume top temperature. Initial visible and IR images at 0850 show the top of a spreading co-ignimbrite-like umbrella plume and an overshooting column emerging from it, both rising off the ground-hugging pyroclastic gravity flow generated by the opening directed blast. The overshooting column had a minimum temperature significantly colder than local ambient atmosphere, indicating substantial undercooling, and a maximum altitude of 31 +/- 2 km at 0920. This large plume system then formed a high-velocity, radially spreading, gravitationally driven current before becoming advected in the wind field at an average downwind velocity of 29 m/s. Reflectance values from visible GOES data change from lower to higher during periods of transition from darker toned Plinian to lighter toned co-ignimbrite plumes indicating that in this case satellite data resolved changes in eruptive style from plumes with a coarser to a finer dominant particle size.
Document ID
19950058957
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Holasek, R. E.
(University of Hawaii, Honolulu, HI United States)
Self, S.
(University of Hawaii, Honolulu, HI United States)
Date Acquired
August 16, 2013
Publication Date
May 10, 1995
Publication Information
Publication: Journal of Geophysical Research
Volume: 100
Issue: B5
ISSN: 0148-0227
Subject Category
Geophysics
Accession Number
95A90556
Funding Number(s)
CONTRACT_GRANT: NAG5-1839
Distribution Limits
Public
Copyright
Other

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