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H 2 O emission rate by the volcanic plume during the 2000–2002 Miyakejima volcanic activity
Author(s) -
Matsushima Nobuo
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl023217
Subject(s) - volcano , plume , geology , earth science , environmental science , geochemistry , atmospheric sciences , meteorology , physics
Extremely intense degassing at Miyakejima volcano (Japan) was observed after the 2000 eruption. The H 2 O emission rate was estimated, using a record of infrared thermal images, at 400 kton/day in November 2000. By April 2002, H 2 O emission rate had decreased exponentially to 100 kton/day. The H 2 O emission rate varied in parallel with the SO 2 emission rate except for the early stage in September 2000. The ratio of H 2 O to SO 2 emission rate after November 2000 remained constant at about 10, which is consistent with the H 2 O/SO 2 ratio in the magma. The large rate of H 2 O and SO 2 emission requires efficient degassing at shallow depth. The agreement between the gas composition of the plume and that of dissolved volatiles in melt inclusions indicates H 2 O discharged from the vent was mostly magmatic in origin after November 2000.