S-wave splitting in the offshore South Island, New Zealand : insights into plate-boundary deformation
Karalliyadda, Sapthala C.
Savage, Martha K.
Sheehan, Anne F.
Collins, John A.
Zietlow, Daniel W.
MetadataShow full item record
Local and regional S-wave splitting in the offshore South Island of the New Zealand plate-boundary zone provides constraints on the spatial and depth extent of the anisotropic structure with an enhanced resolution relative to land-based and SKS studies. The combined analysis of offshore and land measurements using splitting tomography suggests plate-boundary shear dominates in the central and northern South Island. The width of this shear zone in the central South Island is about 200 km, but is complicated by stress-controlled anisotropy at shallow levels. In northern South Island, a broader (>200 km) zone of plate-boundary parallel anisotropy is associated with the transitional faulting between the Alpine fault and Hikurangi subduction and the Hikurangi subduction zone itself. These results suggest S-phases of deep events (∼90 km) in the central South Island are sensitive to plate-boundary derived NE-SW aligned anisotropic media in the upper-lithosphere, supporting a “thin viscous sheet” deformation model.
Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 16 (2015): 2829–2847, doi:10.1002/2015GC005882.
Showing items related by title, author, creator and subject.
Billen, Magali I.; Hirth, Greg (American Geophysical Union, 2005-10-08)The effect of rheology on the evolution of the slab-tip during subduction initiation is analyzed using 2-D numerical flow models. Experimentally determined flow laws have both strong temperature- and stress-dependence, ...
Lin, Ying-Tsong; Duda, Timothy F. (Acoustical Society of America, 2012-07-03)A three-dimensional Cartesian parabolic-equation model with a higher-order approximation to the square-root Helmholtz operator is presented for simulating underwater sound propagation in ocean waveguides. The higher-order ...
A three-dimensional parabolic equation model of sound propagation using higher-order operator splitting and Padé approximants Lin, Ying-Tsong; Collis, Jon M.; Duda, Timothy F. (Acoustical Society of America, 2012-10-08)An alternating direction implicit (ADI) three-dimensional fluid parabolic equation solution method with enhanced accuracy is presented. The method uses a square-root Helmholtz operator splitting algorithm that retains ...