@article{563df9987c4149bcad306ee29660008d,
title = "Seismic Structure of the Antarctic Upper Mantle Imaged with Adjoint Tomography",
abstract = "The upper mantle and transition zone beneath Antarctica and the surrounding oceans are among the poorest-imaged regions of the Earth's interior. Over the last 15 years, several large broadband regional seismic arrays have been deployed, as have new permanent seismic stations. Using data from 297 Antarctic and 26 additional seismic stations south of ~40°S, we image the seismic structure of the upper mantle and transition zone using adjoint tomography. Over the course of 20 iterations, we utilize phase observations from three-component seismograms containing P, S, Rayleigh, and Love waves, including reflections and overtones, generated by 270 earthquakes that occurred from 2001–2003 and 2007–2016. The new continental-scale seismic model (ANT-20) possesses regional-scale resolution south of 60°S. In East Antarctica, thinner continental lithosphere is found beneath areas of Dronning Maud Land and Enderby-Kemp Land. A continuous slow wave speed anomaly extends from the Balleny Islands through the western Ross Embayment and delineates areas of Cenozoic extension and volcanism that span both oceanic and continental regions. Slow wave speed anomalies are also imaged beneath Marie Byrd Land and along the Amundsen Sea Coast, extending to the Antarctic Peninsula. These anomalies are confined to the upper 200–250 km of the mantle, except in the vicinity of Marie Byrd Land where they extend into the transition zone and possibly deeper. Finally, slow wave speeds along the Amundsen Sea Coast link to deeper anomalies offshore, suggesting a possible connection with deeper mantle processes.",
author = "Lloyd, {A. J.} and Wiens, {D. A.} and H. Zhu and J. Tromp and Nyblade, {A. A.} and Aster, {R. C.} and Hansen, {S. E.} and Dalziel, {I. W.D.} and Wilson, {T. J.} and Ivins, {E. R.} and O{\textquoteright}Donnell, {J. P.}",
note = "Funding Information: We thank the many individuals and organizations who have helped with the installation, maintenance, and sadly in some instances the demobilization of 297 remote Antarctic broadband seismic stations used in this study. Although Table S1 lists all stations and their respective data repositories, we particularly wish to thank Timo Tiira, Alfons Eckstaller, Thierry Camelbeeck, and Meijan An for their help in obtaining three-component earthquake seismograms from a number of broadband seismic stations along coastal East Antarctica. Andrew J. Lloyd and Douglas A. Wiens were supported by NSF Grants PLR-1142518, PLR-1246712, and OPP-1744883. Support has also come from NASA Sea-level Change Team ROSES Grant 105393-281945.02.53.03.15. A portion of this researchwas carried out at the Jet Propulsion Laboratory, California Institute ofTechnology, under a contract with the National Aeronautics and SpaceAdministration. This work used the Extreme Science and Engineering Discovery Environment (XSEDE; Towns et al.,), which is supported by National Science Foundation Grant ACI-1548562. Specifically, this work utilized Stampede and Stampede2 at the Texas Advanced Computing Center (TACC) obtained through XSEDE allocation TG-DPP150005. Figures were created using the Generic Mapping Tools (GMT; Wessel & Smith,). The Voigt average shear wave speed structure of ANT-20 can be obtained through the Incorporated Research Institutions for Seismology (IRIS) Earth Model Collaboration (http://ds.iris.edu/ds/products/emc/). The facilities of IRIS Data Services, and specifically the IRIS Data Management Center, were used for access to waveforms, related metadata, and/or derived products used in this study. IRIS Data Services are funded through the Seismological Facilities for the Advancement of Geoscience and EarthScope (SAGE) Proposal of the National Science Foundation under Cooperative Agreement EAR-1261681. Finally, We thank Martha Savage, Ved Lekic, Andreas Fichtner, and an anonymous reviewer for their critiques on this manuscript. Publisher Copyright: {\textcopyright}2019. American Geophysical Union. All Rights Reserved.",
year = "2020",
month = mar,
day = "1",
doi = "10.1029/2019JB017823",
language = "English (US)",
volume = "125",
journal = "Journal of Geophysical Research: Solid Earth",
issn = "2169-9313",
publisher = "American Geophysical Union",
number = "3",
}