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Descent of the ancient Farallon slab drives localized mantle flow below the New Madrid seismic zone
Author(s) -
Forte A. M.,
Mitrovica J. X.,
Moucha R.,
Simmons N. A.,
Grand S. P.
Publication year - 2007
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 - 10.1029/2006gl027895
Subject(s) - geology , intraplate earthquake , seismology , induced seismicity , mantle (geology) , slab , slab window , seismic zone , lithosphere , geophysics , plate tectonics , seismic tomography , subduction , tectonics , oceanic crust
The great earthquake sequence that occurred in the central Mississippi River Valley during the winter of 1811–1812 is unprecedented in the historical record of seismicity within stable continental plate interiors. We show, using viscous flow models based on high resolution seismic tomography, that the descent of the ancient Farallon slab into the deep mantle beneath central North America induces a highly localized flow directly below the New Madrid seismic zone (NMSZ). This localization arises because of structural variability in the Farallon slab and the low‐viscosity of the sub‐lithospheric upper mantle, and it represents a heretofore unrecognized and possibly significant driving mechanism for the enigmatic intraplate seismicity.