Asymmetric ocean basins

Abstract

Research Article| January 01, 2010 Asymmetric ocean basins Giuliano Panza; Giuliano Panza 1Dipartimento di Scienze della Terra, Università di Trieste, 34127 Trieste, Italy, and Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 1, 34151 Trieste, Italy Search for other works by this author on: GSW Google Scholar Carlo Doglioni; Carlo Doglioni 2Dipartimento di Scienze della Terra, Università Sapienza, 00185 Rome, Italy, and Istituto di Geologia Ambientale e Geoingegneria (Consiglio Nazionale delle Richerche, CNR-IGAG), 00185 Rome, Italy Search for other works by this author on: GSW Google Scholar Anatoli Levshin Anatoli Levshin 3Department of Physics, University of Colorado, Boulder, Colorado 80309, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Giuliano Panza 1Dipartimento di Scienze della Terra, Università di Trieste, 34127 Trieste, Italy, and Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 1, 34151 Trieste, Italy Carlo Doglioni 2Dipartimento di Scienze della Terra, Università Sapienza, 00185 Rome, Italy, and Istituto di Geologia Ambientale e Geoingegneria (Consiglio Nazionale delle Richerche, CNR-IGAG), 00185 Rome, Italy Anatoli Levshin 3Department of Physics, University of Colorado, Boulder, Colorado 80309, USA Publisher: Geological Society of America Received: 28 Jul 2009 Revision Received: 05 Aug 2009 Accepted: 10 Aug 2009 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2010 Geological Society of America Geology (2010) 38 (1): 59–62. https://doi.org/10.1130/G30570.1 Article history Received: 28 Jul 2009 Revision Received: 05 Aug 2009 Accepted: 10 Aug 2009 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Giuliano Panza, Carlo Doglioni, Anatoli Levshin; Asymmetric ocean basins. Geology 2010;; 38 (1): 59–62. doi: https://doi.org/10.1130/G30570.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract While the superficial expression of oceanic ridges is generally symmetric, their deeper roots may be asymmetric. Based on a surface wave tomographic three-dimensional model of the Earth's upper 300 km, we construct a global cross section parallel to the equator of the net rotation of the lithosphere, the so-called tectonic equator. Shear wave velocities indicate a difference between the western and eastern flanks of the three major oceanic rift basins (Pacific, Atlantic, and Indian ridges). In general, the western limbs have a faster velocity and thicker lithosphere relative to the eastern or northeastern one, whereas the upper asthenosphere is faster in the eastern limb than in the western limb. We interpret the difference between the two flanks as the combination of mantle depletion along the oceanic rifts and of the westward migration of the ridges and the lithosphere relative to the mantle. The low-velocity layer in the upper asthenosphere at the depth of 120–200 km is assumed to represent the decoupling between the lithosphere and the underlying mantle. It is also well defined by the distribution of radial anisotropy that reaches minimum values close to the rifts, but with an eastward offset. These results could be explained in the frame of the westward drift of the lithosphere relative to the underlying mantle. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.