FN Archimer Export Format
PT J
TI Modeling of anisotropy in the lithosphere and asthenosphere for real Earth cases: a critical assessment of the impact on SKS measurements
BT 
AF Lamarque, Gaelle
   Piana Agostinetti, Nicola
AS 1:1,2;2:3,4;
FF 1:;2:;
C1 Laboratoire Geosciences Ocean, UMR6538, IUEM, UBO Plouzané ,France
   Ifremer, Geosciences Marines, Centre de Brest Plouzané ,France
   Department of Geodynamics and Sedimentology, Faculty of Earth Sciences, Geography and AstronomyUniversity of Vienna Vienna, Austria
   Centro Nazionale Terremoti, Istituto Nazionale di Geofisica e Vulcanologia Rome, Italy
C2 UBO, FRANCE
   IFREMER, FRANCE
   UNIV VIENNA, AUSTRIA
   INGV, ITALY
SI BREST
SE PDG-REM-GM-LGS
UM LGO
IN WOS Ifremer UPR
   copubli-france
   copubli-europe
   copubli-univ-france
IF 3.848
TC 5
UR https://archimer.ifremer.fr/doc/00630/74181/73777.pdf
   https://archimer.ifremer.fr/doc/00630/74181/76564.pdf
LA English
DT Article
AB We investigate effects of realistic Earth's lithospheric structures on measurements of SKS seismic waves birefringence, which could be perturbed by different factors. We present SKS measurements recorded in four different tectonic settings. For each case, a realistic lithospheric structure is assumed and synthetic SKS splitting measurements are compared with the field observations. Our results show that: (a) in simple case, where anisotropy is aligned in both the lithospheric mantle and the asthenosphere, the SKS measurements can be safely interpreted as dominantly related to asthenospheric mantle flow; (b) in case of multi‐layer anisotropy in the lithospheric mantle, SKS measurement can corresponds to a combination of the different fast axis orientations and intensities of the anisotropic layers, dominated by the layer with stronger anisotropy; (c) across orogens, where highly anisotropic ≥ 10%) crustal sections are present, a relevant percent (30‐40%) of SKS measurement can be explained by crustal contributions, with additional challenge related to the different direction of retrieved and expected symmetry axis; and finally (d) in subduction zones, even in absence of mantle corner flow, subducted crust materials can interplay with the overriding plate to generate an interpretable SKS observation. We conclude that complex crustal and/or lithospheric anisotropy can lead to erroneous SKS splitting parameters interpretations in terms of mantle deformations. We show in particular that complex crustal anisotropy can produce both important time delay and back‐azimuthal pattern. We also confirm that SKS splitting parameters do not allow to identify the presence of more than two anisotropic layers in the mantle. 
PY 2020
PD AUG
SO Journal Of Geophysical Research-solid Earth
SN 2169-9313
PU American Geophysical Union (AGU)
VL 125
IS 8
UT 000582684200008
DI 10.1029/2019JB018978
ID 74181
ER

EF