PARTICLE FALLOUT, THERMAL DISEQUILIBRIUM AND VOLCANIC PLUMES

被引:115
作者
WOODS, AW
BURSIK, MI
机构
[1] Institute of Geophysics and Planetary Physics, A-025, Scripps Institution of Oceanography, UCSD, La Jolla, 92093, CA
[2] Earth and Space Sciences Division, MS 183-501, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, 91109, CA
关键词
D O I
10.1007/BF00298156
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
We develop a model of a volcanic eruption column that includes the effects of fallout of pyroclasts and thermal disequilibrium. We show that clast fallout, with no thermal disequilibrium, has only a small effect upon the column. However, disequilibrium changes column behaviour significantly, and can even induce collapse. Our results may explain the lower plume heights and less widely dispersed fallout of cone-forming eruptions contrasted with sheet-forming eruptions. The model also predicts that the transition from the gas thrust to the convective region in a column results in an inflection in dispersal curves, that some features of the stratigraphy common to many fall deposits may result from column velocity structure, and that there may exist a region near the volcanic vent in which maximum pyroclast size does not decrease significantly with distance.
引用
收藏
页码:559 / 570
页数:12
相关论文
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