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Viscoelastic deformation from North Anatolian Fault Zone earthquakes and the eastern Mediterranean GPS velocity field
Author(s) -
Hearn Elizabeth H.,
Hager Bradford H.,
Reilinger Robert E.
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 - 10.1029/2002gl014889
Subject(s) - north anatolian fault , geology , asthenosphere , viscoelasticity , seismology , fault (geology) , global positioning system , mediterranean sea , geodesy , lithosphere , mediterranean climate , geography , tectonics , telecommunications , physics , archaeology , computer science , thermodynamics
We have modeled linear viscoelastic relaxation of a uniform‐viscosity asthenosphere following large earthquakes in the Aegean‐Anatolian region during the 20th century to evaluate whether this process contributes significantly to the regional velocity field. We address in particular whether southward motion of the Aegean Sea region relative to central Anatolia (and thus extension of western Turkey) can be attributed to a postseismic strain pulse. Our models show that postseismic relaxation of a thick (250 km) viscoelastic substrate cannot generate the observed extension in western Turkey, regardless of the choice of viscosity. We also find that the asthenosphere viscosity must exceed about 5 × 10 20 Pa s, at least north of the North Anatolian Fault Zone (NAFZ), to be consistent with low GPS site velocities in the Black Sea region and highly localized strain around the fault.