岡山大学 地球科学研究報告
Published by Okayama University Earth Science Reports Editorial Committee

雲仙火山1990~94年の火山活動に伴う火山灰水溶性物質

Akagi, Seishi
Yamamoto, Masahiro
Abstract
Water-soluble materials on volcanic ash from the Unzen volcano collected from February, 1991 to July, 1994 were chemically analyzed. They were similar in chemical characteristics to those obtained from other volcanoes. Chemical compositions varied even for materials from the same pyroclastic flow. C1 contens increased with increasing residence time of volcanic ash in air, but SO4 contents were almost fixed. It therefore seems that the reaction of volcanic ash with HC1 proceeds even at low temperatures, whereas the reaction with SO2 takes place only at high temperatutes.
Keywords
volcanic ash
volcanic gas
Unzen volcano
C1/SO4 ratio
water-soluble
material
ISSN
1340-7414
NCID
AN10506284