Atmospheric dust dispersal analyzed by granulometry of the Misers Gold event
- Los Alamos National Lab., NM (United States)
Granulometric analysis of ejecta from Misers Gold high explosive cratering experiment demonstrates that atmospheric dust dispersal can be evaluated by particle-size distribution data. From size analyses of the Misers Gold preshot test bed alluvium, ejects, and sweep-up materials collected out to 35 crater radii (1227 m), we find that approximately 5.9 [times] 10[sup 6] kg ([approximately]11% of the total crater ejecta mass) was depleted from the crater ejecta deposits and likely represents the portion of the cratered mass initially lofted into atmospheric suspension. The dominant size range of this lofted dust was 88 to 2000 [mu]m with a mean diameter by mass of 384[mu]m. In addition to the dust lofted in the explosion column, dust in the size range of 100-800 [mu]m was swept up from the ground by the explosive air blast and base surge dominantly between ranges of 10 and 18 crater radii (360 and 650 m from ground zero). This sweep-up dust was convectively drawn into the column and contributed up to 2% of the total mass of lofted. Based on the measured abundance of coarse (>250 [mu]m diameter) dust particles in the estimated lofted dust, it is likely that about 70% of this lofted mass fell out within about 1 hour, such that the remaining dust cloud mass was [approximately] 1.8 [times] 10[sup 6] kg, which is equivalent to a dust lofted per unit blast yield of 0.5 kT/kT or about 4% of the crater ejecta mass. This study supports the hypothesis that if initial distributions can be constrained, the volume of dust lofted into atmospheric suspension from large surface explosions can be estimated from analysis of particle-size distributions of ejecta deposited near the explosion. This result may have particular applications to study of the atmospheric effects of historic and prehistoric volcanic eruptions. 15 refs., 16 figs., 2 tabs.
- OSTI ID:
- 6903270
- Journal Information:
- Journal of Geophysical Research; (United States), Vol. 98:B1; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
CRATERING EXPLOSIONS
TOTAL SUSPENDED PARTICULATES
DUSTS
PARTICLE SIZE
EARTH ATMOSPHERE
AMBIENT TEMPERATURE
PARTICULATES
VOLCANOES
HISTORICAL ASPECTS
ABUNDANCE
AIR
DEPOSITS
DISPERSIONS
DISTRIBUTION
GLOBAL ASPECTS
MASS
MATERIALS
PARTICLES
RANGE
SIZE
SUPPORTS
SURFACE EXPLOSIONS
EXPLOSIONS
FLUIDS
GASES
MECHANICAL STRUCTURES
580000* - Geosciences
540110