Mapping fine-scale heterogeneities within the continental mantle lithosphere beneath Scotland: Combining active- and passive-source seismology

Research Article| June 01, 2003 Mapping fine-scale heterogeneities within the continental mantle lithosphere beneath Scotland: Combining active- and passive-source seismology Eugenio Asencio; Eugenio Asencio 1Department of Geology, University of Puerto Rico, Mayagüez, 00681-9017, Puerto Rico Search for other works by this author on: GSW Google Scholar James H. Knapp; James H. Knapp 2 Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA Search for other works by this author on: GSW Google Scholar Thomas J. Owens; Thomas J. Owens 2 Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA Search for other works by this author on: GSW Google Scholar George Helffrich George Helffrich 3Department of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, UK Search for other works by this author on: GSW Google Scholar Geology (2003) 31 (6): 477–480. https://doi.org/10.1130/0091-7613(2003)031<0477:MFHWTC>2.0.CO;2 Article history received: 03 Sep 2002 rev-recd: 05 Feb 2003 accepted: 08 Feb 2003 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Eugenio Asencio, James H. Knapp, Thomas J. Owens, George Helffrich; Mapping fine-scale heterogeneities within the continental mantle lithosphere beneath Scotland: Combining active- and passive-source seismology. Geology 2003;; 31 (6): 477–480. doi: https://doi.org/10.1130/0091-7613(2003)031<0477:MFHWTC>2.0.CO;2 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 We analyze new observational evidence for seismic velocity discontinuities in teleseismic receiver functions in comparison to well-documented discontinuities observed in marine reflection profiles and wide-angle reflection-refraction profiles in northern Scotland. Our study establishes the viability of mapping small amplitude P to S (Ps) converted phase arrivals from the upper mantle generated in the P-wave coda of teleseismic earthquakes using well-known receiver function methods. Teleseismic earthquakes recorded by a small array of portable broadband stations and permanent short-period stations are used to ascertain the lateral extent of velocity discontinuities within the continental mantle lithosphere beneath Scotland. Radial receiver functions contain distinct Ps converted phases at ∼3.1–3.2 s (Moho) and at 4.5–5.2 s (upper mantle depths) after the direct P wave. We suggest that the upper mantle Ps phase originates from a high-velocity and/or anisotropic layer within the upper mantle. At two stations, ORE and BACA, located along the northern shoreline of Scotland, these upper mantle phases can be correlated with the W reflector, a bright, regionally extensive seismic reflector previously observed on marine deep seismic reflection and wide-angle refraction-reflection profiles. However, the variability in physical characteristics (depth, thickness, azimuthal variations in the vertical structure, velocity contrast, and anisotropic properties) suggests the possibility that there may be multiple layered reflectors in the upper mantle beneath northern Scotland and raises doubt about the global significance of some of these reflectors. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.