ORIGINAL PAPER Shear Wave Splitting and Mantle Anisotropy: Measurements, Interpretations, and New Directions Maureen D. Long Paul G. Silver Received: 5 February 2009 / Accepted: 3 June 2009 / Published online: 27 June 2009 Ó The Author(s) 2009. This article is published with open access at Springerlink.com Abstract Measurements of the splitting or birefringence of seismic shear waves that have passed through the Earth’s mantle yield constraints on the strength and geometry of elastic anisotropy in various regions, including the upper mantle, the transition zone, and the D 00 layer. In turn, information about the occurrence and character of seismic anisotropy allows us to make inferences about the style and geometry of mantle flow because anisotropy is a direct consequence of deformational processes. While shear wave splitting is an unambiguous indicator of anisotropy, the fact that it is typically a near-vertical path-integrated measure- ment means that splitting measurements generally lack depth resolution. Because shear wave splitting yields some of the most direct constraints we have on mantle flow, however, understanding how to make and interpret splitting measurements correctly and how to relate them properly to mantle flow is of paramount importance to the study of mantle dynamics. In this paper, we review the state of the art and recent developments in the measurement and interpretation of shear wave splitting—including new measurement methodologies and forward and inverse modeling techniques,—provide an overview of data sets from different tectonic settings, show how they help us relate mantle flow to surface tectonics, and discuss new directions that should help to advance the shear wave splitting field. Keywords Shear wave splitting Seismic anisotropy Mantle flow Mantle dynamics 1 Introduction Knowledge of present-day dynamical processes taking place within the Earth’s mantle is crucial to our understanding of the workings of our planet’s interior and how it has evolved M. D. Long (&) Department of Geology and Geophysics, Yale University, New Haven, CT 06520, USA e-mail: [email protected] P. G. Silver Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA 123 Surv Geophys (2009) 30:407–461 DOI 10.1007/s10712-009-9075-1
Shear Wave Splitting and Mantle Anisotropy: Measurements, Interpretations, and New Directions
May 23, 2023
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Related Documents
