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Characteristic non‐down‐dip‐extensional intermediate‐depth earthquakes immediately beneath the volcanic front in South Kyushu, Japan
Author(s) -
Iguchi Masato,
Ishihara Kazuhiro,
Tatsumi Yoshiyuki
Publication year - 1995
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 - 10.1029/95gl01772
Subject(s) - geology , seismology , volcano , fault plane , extensional definition , seismic zone , mantle (geology) , fault (geology) , geophysics , tectonics , induced seismicity
The hypocentral distribution and fault‐plane solutions of intermediate‐depth earthquakes in South Kyushu, Japan were investigated. The dipping seismic zone bends at a depth of 60∼70 km and continues to a depth of 180 km and the majority of the source mechanisms are down‐dip‐extension (DE). Non‐DE earthquakes are concentrated at depths of 100–120 km beneath the volcanic region, that is, upward and westward of the dipping seismic zone, and have vertical P‐ and horizontal T‐ axes. The occurrence of Non‐DE earthquakes may be related to dehydration processes at the base of the mantle wedge.