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Seismic anisotropy beneath east Greenland revealed by shear wave splitting
Author(s) -
Ucisik Nur,
Gudmundsson Ólafur,
Priestley Keith,
Larsen Tine B.
Publication year - 2005
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 - 10.1029/2004gl021875
Subject(s) - geology , shear wave splitting , lithosphere , anisotropy , seismic anisotropy , seismology , tectonics , mid atlantic ridge , polarization (electrochemistry) , ridge , shear (geology) , perpendicular , crust , shear waves , geophysics , mantle (geology) , petrology , paleontology , hydrothermal circulation , geometry , physics , quantum mechanics , chemistry , mathematics
Seismic anisotropy was investigated by measuring shear wave splitting at 7 broadband stations in eastern Greenland. Splitting parameters (fast polarization and time delay) were determined for SKS and SKKS phases. Fast polarizations are oriented roughly parallel to the east Greenland coast at 5 stations, while for two they are nearly perpendicular to the coast. The anisotropy at 5 is unrelated to the spreading direction of the North Atlantic or absolute plate motion. The fast polarization direction can be related to tectonic fabric in the Caledonides in the north, suggesting that anisotropy is frozen in the lithosphere, deformed coherently with depth. Another explanation of the coast parallel fast polarization is asthenospheric flow along the Mid‐Atlantic Ridge at the time of opening of the ocean inducing fabric in the thickened lithosphere. The time delays (0.5–1.3 s) do, however, require that fabric to be strong or distributed over a substantial depth range.