16 Hits in 5.0 sec

MSAT—A new toolkit for the analysis of elastic and seismic anisotropy

Andrew M. Walker, James Wookey
2012 Computers & Geosciences  
The design and content of MSAT, a new Matlab toolkit for the study and analysis of seismic and elastic anisotropy, is described.  ...  Along with a brief introduction to the basic theory of anisotropic elasticity and a guide to the functions provided by the toolkit, three example applications are discussed.  ...  have described a Matlab toolkit designed to simplify the analysis and modelling of elastic and seismic anisotropy.  ... 
doi:10.1016/j.cageo.2012.05.031 fatcat:pelibwzxnfae7mhvlmbgo3o37e

Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone

Takayoshi Nagaya, Andrew M. Walker, James Wookey, Simon R. Wallis, Kazuhiko Ishii, J. -Michael Kendall
2016 Scientific Reports  
Here, we utilize this anisotropy and show how an analysis of seismic anisotropy that incorporates measured ray path geometries in the Ryukyu arc can constrain the distribution, orientation and amount of  ...  We find more than 54% of the wedge must consist of antigorite and the alignment must change from vertically aligned to parallel to the slab.  ...  Mainprice of Montpellier University and J. F. Di Leo of Bristol University for providing comments about Matlab tool kits, MTEX and MSAT used for programing in this study, respectively.  ... 
doi:10.1038/srep29981 pmid:27436676 pmcid:PMC4951697 fatcat:gfewozbiwzgctp7y6qft3qfwtu

Modeling of seismic anisotropy observations reveals plausible lowermost mantle flow directions beneath Siberia

Neala Creasy, Angelo Pisconti, Maureen D. Long, Christine Thomas
2021 Geochemistry Geophysics Geosystems  
There are several proposed mechanisms for D″ seismic anisotropy, including the shape preferred orientation (SPO) of melt inclusions (or other elastically distinct material) and the crystallographic preferred  ...  Observations of seismic anisotropy are a powerful tool for mapping deformation within the Earth (e.g., Long & Becker, 2010) , and are often used to study deformation and flow in the upper mantle (e.g.,  ...  Long, and from the European Union's Horizon 2020 research and innovation program under the Marie Slodowska-Curie grant agreement No. 642029-ITN CREEP (A. Pisconti).  ... 
doi:10.1029/2021gc009924 fatcat:d367xj7afzbxncjdyqmy6jfy2u

Seismic anisotropy from compositional banding in granulites from the deep magmatic arc of Fiordland, New Zealand

Daria Cyprych, Sandra Piazolo, Bjarne S.G. Almqvist
2017 Earth and Planetary Science Letters  
14 15 We present calculated seismic velocities and anisotropies of mafic granulites and eclogites 16 from the Cretaceous deep lower crust (~40-65 km) of Fiordland, New Zealand.  ...  The predicted mean P-and S-wave velocities are 21 consistent with previously published data for similar lithologies from other locations (e.g., 22 *Manuscript Click here to view linked References  ...  To visualize anisotropy and velocity 205 distribution, and S-wave polarization planes in sample reference frame, we used the 206 MATLAB Seismic Anisotropy Toolkit (MSAT; Walker and Wookey, 2012).  ... 
doi:10.1016/j.epsl.2017.08.017 fatcat:wd3ftthxzjhypmpohgmtesml54

Synthetic seismic anisotropy models within a slab impinging on the core–mantle boundary

Sanne Cottaar, Mingming Li, Allen K. McNamara, Barbara Romanowicz, Hans-Rudolf Wenk
2014 Geophysical Journal International  
S U M M A R Y The lowermost few hundreds of kilometres of the Earth's mantle are elastically anisotropic; seismic velocities vary with direction of propagation and polarization.  ...  Combining the crystal pole orientations with single crystal elastic constants results in seismically distinguishable models of seismic anisotropy.  ...  A C K N O W L E D G E M E N T S Some of the calculations and figures make use of the Matlab Seismic Anisotropy Toolkit (  ... 
doi:10.1093/gji/ggu244 fatcat:x6627hzj3fhxlh2ojtragzwjou

Seismic Anisotropy in Subduction Zones: Evaluating the Role of Chloritoid

Jungjin Lee, Mainak Mookherjee, Taehwan Kim, Haemyeong Jung, Reiner Klemd
2021 Frontiers in Earth Science  
New elasticity data of single-crystal chloritoid showed a strong elastic anisotropy of chloritoid with 47% for S-waves (VS) and 22% for P-waves (VP), respectively.  ...  The combination of the LPO and the elastic anisotropy of the chloritoid aggregates produced a strong S-wave anisotropy with a maximum AVS of 18% and a P-wave anisotropy with an AVP of 10%.  ...  Calculation of the Seismic Velocity and Anisotropy The seismic anisotropy of single-crystal chloritoid and that of polycrystalline chloritoid were obtained with the MSAT toolkit (Walker and Wookey, 2012  ... 
doi:10.3389/feart.2021.644958 fatcat:ewkljdfqqnachclg4thc3auh2y

Discriminating between causes of D" anisotropy using reflections and splitting measurements for a single path

Angelo Pisconti, Christine Thomas, James Wookey
2019 Journal of Geophysical Research - Solid Earth  
Full terms of use are available: Abstract Knowledge of deep mantle deformation is based on seismic anisotropy: the variation of seismic wave speed and polarization with direction.  ...  We find complex azimuthal and distance variation for both polarities of D″ reflections and shear wave splitting parameters, which rules out a simple style of anisotropy-such as vertical transverse isotropy-for  ...  allow us to explore anisotropy in new regions.  ... 
doi:10.1029/2018jb016993 fatcat:xfrqfe5o6fc7ff4rdulikbme3i

Constraining lowermost mantle anisotropy with body waves: A synthetic modeling study

Neala Creasy, Angelo Pisconti, Maureen D Long, Christine Thomas, James Wookey
2019 Geophysical Journal International  
Black bars show predicted splitting over a range inclinations and 851 azimuths, as computed using the MSAT toolkit (Walker and Wookey, 2012).  ...  In each iteration, we randomly choose a new azimuthal distribution 284 of raypaths for a new synthetic dataset with varying characteristics (such as the number 285 and type of observations, described in  ...  Models A, C, and D illustrate situations where there is an onset of 874 44 anisotropy at the D" discontinuity while Model B invokes both a phase change (from Br to 875 Ppv) and the onset of anisotropy.  ... 
doi:10.1093/gji/ggz049 fatcat:jdaqjy4covgfheueuwabob2xzy

Lowermost mantle anisotropy beneath Africa from differential SKS‐SKKS shear‐wave splitting

M.C. Reiss, M.D. Long, N. Creasy
2019 Journal of Geophysical Research - Solid Earth  
for the formation of upwellings at their edges.  ...  We investigate seismic anisotropy in the lowermost mantle in the vicinity of the African large low shear velocity province (LLSVP) using observations of differential SKS-SKKS shear-wave splitting.  ...  from seismic anisotropy at the base of the mantle.  ... 
doi:10.1029/2018jb017160 fatcat:ehy6ojbnf5bi5hzlsdlfkpdsje

The Role of Oceanic Transform Faults in Seafloor Spreading: A Global Perspective From Seismic Anisotropy

Caroline M. Eakin, Catherine A. Rychert, Nicholas Harmon
2018 Journal of Geophysical Research - Solid Earth  
Observations are sparse however, given the remoteness of the 4 oceans and the difficulties of seismic instrumentation.  ...  Key Points • Seismic anisotropy beneath oceanic transforms revealed by global source-side splitting analysis • Results characterised by nulls (60%) and azimuthally dependent splitting • Consistent with  ...  we therefore explore different dip angles of the 479 fast symmetry axis by rotating the elastic tensor using the Matlab and Seismic 480 Anisotropy Toolkit (MSAT) [Walker and Wookey, 2012] (Figure S7).  ... 
doi:10.1002/2017jb015176 pmid:29938151 pmcid:PMC5993317 fatcat:k2rhsn4w65hblhjtpmh4742lta

Mid-mantle anisotropy in subduction zones and deep water transport

Andy Nowacki, J.-Michael Kendall, James Wookey, Asher Pemberton
2015 Geochemistry Geophysics Geosystems  
We invert for the orientation of several mechanisms-subject to uncertainties in mineralogy and deformation-and the best fit is given by updip flattening in a style of anisotropy common to hydrous phases  ...  However, there is no decrease in the amount of splitting with depth, as would be the case for a metastable tongue of olivine which thins with depth, suggesting this is not the cause.  ...  The data for this paper are available from the Data Management Center (DMC) of the Incorporated Research Institutions for Seismology (IRIS;, using the information in supporting information  ... 
doi:10.1002/2014gc005667 fatcat:zfw5mhy52za6jca73tqmupog5a

Constraints on olivine deformation from SKS shear‐wave splitting beneath the southern Cascadia subduction zone back‐arc

E. Löberich, M. D. Long, L. S. Wagner, E. Qorbani, G. Bokelmann
2021 Geochemistry Geophysics Geosystems  
Seismic anisotropy offers the unique opportunity to constrain subsurface deformation and the mechanism behind it.  ...  For example, shear-waves that encounter anisotropy due to lattice-preferred orientation (LPO) of mineral assemblages experience polarization differences along their respective fast and slow propagation  ...  Acknowledgments Our work would not have been possible without the maintenance of several seismographic networks, namely the US National Seismic Network (10.7914/ SN/US), the USArray Transportable  ... 
doi:10.1029/2021gc010091 fatcat:nzafak4zebfn3cgsm2ahb2c2hm

Seismic Anisotropy and Its Geodynamic Implications in Iran, the Easternmost Part of the Tethyan Belt

Amir Sadeghi-Bagherabadi, Lucia Margheriti, Abdelkrim Aoudia, Farhad Sobouti
2018 Tectonics  
The variation of the convergence obliquity along the Alborz and Zagros inferred from analysis of geodetic data implies that a change in the pattern of lithospheric deformation and the consequent anisotropy  ...  In this study, we use the results of seismic anisotropy as inferred from shear wave splitting analyses of SKS phases to propose a geodynamical model of the Arabia-Eurasia collision zone.  ...  For the purpose of this modeling we used the MSAT toolkit (Walker & Wookey, 2012) .  ... 
doi:10.1029/2018tc005209 fatcat:aidcd2ouorgipcypzgclwngcqi

Complex anisotropy beneath the Peruvian flat slab from frequency-dependent, multiple-phase shear wave splitting analysis

Caroline M. Eakin, Maureen D. Long
2013 Journal of Geophysical Research - Solid Earth  
We conduct a detailed shear wave splitting analysis at a long-running seismic station (NNA) located near Lima, Peru.  ...  Here we present measurements of seismic anisotropy to investigate mantle flow beneath the Peruvian flat-slab segment, the largest present-day region of flat subduction.  ...  and were accessed via the Data Management System (DMS) of the Incorporated Research Institutions for Seismology (IRIS).  ... 
doi:10.1002/jgrb.50349 fatcat:o2knuhk3cjeovb6xot5pzme7ju

Mimetization of the elastic properties of cancellous bone via a parameterized cellular material

Lucas Colabella, Adrián P. Cisilino, Guillaume Häiat, Piotr Kowalczyk
2017 Biomechanics and Modeling in Mechanobiology  
ACKNOWLEDGEMENTS This work has been supported by projects PIRSES-GA2009_246977 "Numerical Simulation in Technical Sciences" of the Marie Curie Actions  ...  Toolkit (MSAT) by Walker and Wookey (2012 Kabel et al. (1999a Kabel et al. ( , 1999b .  ...  the determination of the symmetry Cartesian coordinate system, the transformations into vector forms, the symmetry decompositions and normalizations were performed using the Matlab Seismic Anisotropy  ... 
doi:10.1007/s10237-017-0901-y pmid:28374083 fatcat:pf2xclnsrbb2hmmrhokqjvurz4
« Previous Showing results 1 — 15 out of 16 results