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Unfolding the subducting plate in the central New Hebrides Island ARC: Geometrical argument for detachment of part of the downgoing slab
Author(s) -
Chatelain JeanLuc,
Guillier Bertrand,
Gratier JeanPierre
Publication year - 1993
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 - 10.1029/93gl00681
Subject(s) - geology , slab , seismology , island arc , seismic zone , subduction , geophysics , tectonics , induced seismicity
In the central part of the New Hebrides island arc a sizable gap exists in the seismic activity. Seismic observations in the zone of the gap have been previously interpreted as either related to a detachment of part of the downgoing slab or associated with a continuous slab. We give a geometrical argument which, added the seismic observations from these previous studies, adds one step in favor of the detachment hypothesis. After unfolding the downgoing plate and restoring it to its initial state, using a 3D balance technique, we show that the gap can be filled with three pieces. Two of these pieces are seismic zones located beneath the seismic gap and the third one is a deep (550 – 650 km) seismic zone located about 200 km north‐east of the arc. These three pieces could be detached parts of the subducting plate.