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Unbending combined with dehydration embrittlement as a cause for double and triple seismic zones
Author(s) -
Wang Kelin
Publication year - 2002
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 - 10.1029/2002gl015441
Subject(s) - embrittlement , slab , induced seismicity , geology , fluid pressure , mantle (geology) , seismology , crust , dehydration , materials science , geophysics , composite material , chemistry , mechanics , biochemistry , physics
Using a model of elastic‐perfectly plastic plate, I demonstrate that plate unbending combined with dehydration embrittlement can account for the morphology and stresses of double or triple seismic zones (DSZ's or TSZ's) observed in many subducting slabs. Densifying metamorphic reactions may induce tensile stresses as well as high pore fluid pressures in the slab crust and thus generate the upper seismicity band of the TSZ. Limited dehydration may moderately elevate the fluid pressure in the slab mantle, but unbending usually dominates mantle stresses and results in another two seismicity bands. DSZ's are underdeveloped TSZ's.