Surface wave tomography of the upper mantle beneath the Reykjanes Ridge with implications for ridge–hot spot interaction

2007 ◽  
Vol 112 (B8) ◽  
Author(s):  
Andrew A. Delorey ◽  
Robert A. Dunn ◽  
James B. Gaherty
Keyword(s):  
Surface Wave ◽  
Upper Mantle ◽  
Hot Spot ◽  
Surface Wave Tomography ◽  
Reykjanes Ridge ◽  
Wave Tomography

scholarly journals Effect of earthquakes on ambient noise surface wave tomography in upper-mantle studies

2016 ◽  
Vol 205 (2) ◽  
pp. 1208-1220 ◽  
Author(s):  
Tatiana Yanovskaya ◽  
Tatiana Koroleva ◽  
Eugenia Lyskova
Keyword(s):  
Surface Wave ◽  
Upper Mantle ◽  
Ambient Noise ◽  
Surface Wave Tomography ◽  
Wave Tomography

Upper mantle structure beneath the Dinarides and the Alps from surface wave tomography

2020 ◽  
Author(s):  
Petr Kolínský ◽  
Tena Belinić ◽  
Josip Stipčević ◽  
Irene Bianchi ◽  
Florian Fuchs ◽  
...  
Keyword(s):  
Surface Wave ◽  
Phase Velocity ◽  
Upper Mantle ◽  
Seismic Velocity ◽  
Dispersion Curves ◽  
Surface Wave Tomography ◽  
Local Dispersion ◽  
Wave Phase ◽  
Wave Tomography ◽  
The Alps

<p>The Alpine-Dinarides are a complex orogenic system, with its tectonic evolution controlled by the ongoing convergence between Eurasian and African plates with the Adriatic microplate wedged between them. Our study focuses on the upper mantle of the wider Alpine-Dinarides region, and we present surface-wave tomography of two overlapping subregions, interpreting the seismic velocity features in the context of regional geodynamics.</p><p>In the first part, we use records of 151 teleseismic earthquakes (2010-2018) at 98 stations distributed across the wider Dinarides region. Surface-wave phase velocities are measured in the range of 30 – 160 s by the two-station method at pairs of stations aligned along the great circle paths with the epicenters. We apply several data-quality tests before the dispersion curves are measured. We use Rayleigh waves recorded on both radial and vertical components. Only the dispersions measured coherently at both components are used for the tomography. In total, we reach the number of 9000 phase velocity measurements for the period of 50 s. Tomographic results including resolution estimates are provided for various frequencies; the local dispersion curves are inverted for depths from the surface down to 300 km. Results are shown as maps for various depths and as cross-sections along several profiles of shear-wave velocities in the whole region.</p><p>The other study focuses on the Alps. The AlpArray seismic network stretches hundreds of kilometers in width and more than thousand kilometers in length. It is distributed over the greater Alpine region (Europe) and consists of around 250 temporary and around 400 permanent broadband stations with interstation distances around 40 km. The earthquakes are selected between years 2016-2019. The methodology differs from the Dinarides case in a sense, that while before we used many earthquakes and less stations pairs (due to sparser station coverage), for the Alps, we use less earthquakes (32) and many more stations pairs (tens of thousands) making use of the dense station coverage of the AlpArray network.</p><p>Results of the depth inversion of the local dispersion measurements for the Alps are compared with local surface-wave phase-velocity measurement obtained from the (sub)array approach.</p>

The formation of continental roots

Geology ◽  
2020 ◽  
Author(s):  
Keith Priestley ◽  
Tak Ho ◽  
Dan McKenzie
Keyword(s):  
Surface Wave ◽  
Upper Mantle ◽  
Pure Shear ◽  
Seismic Wave Propagation ◽  
High Viscosity ◽  
Crystallographic Axis ◽  
Surface Wave Tomography ◽  
Mantle Lithosphere ◽  
Wave Tomography ◽  
Reduced Density

New evidence from seismic tomography reveals a unique mineral fabric restricted to the thick mantle lithosphere beneath ancient continental cratons, providing an important clue to the formation of these prominent and influential features in Earth’s geological history. Olivine, the dominant mineral of Earth’s upper mantle, has elastic properties that differ along its three crystallographic axes, and preferential alignment of individual olivine grains during plastic deformation can affect the bulk nature of seismic-wave propagation. Surface-wave tomography has shown that over most of Earth, deformation of the mantle lithosphere has oriented olivine crystals with the fast axis in the horizontal plane, but at depths centered at ~150 km within cratonic continental-lithosphere roots, the fast crystallographic axis is preferentially aligned vertically. Because of the high viscosity of the cratonic roots, this fabric is likely to be a vestige from craton formation. Geochemical and petrological studies of upper-mantle garnet-peridotite nodules demonstrate that the cratonic mantle roots are stabilized by their reduced density, which was caused by melt removal at much shallower depths than those from which the nodules were subsequently extracted. The mineral fabric inferred from surface-wave tomography suggests that horizontal shortening carried the depleted zone downward after the melt-depletion event to form the thick continental roots, stretching the depleted material in the vertical dimension by pure shear and causing the fast crystallographic axis to be aligned vertically. This seismological fabric at ~150 km is evidence of the shortening event that created the cratonic roots.

scholarly journals High-resolution surface wave tomography beneath the Aegean-Anatolia region: constraints on upper-mantle structure

2012 ◽  
Vol 190 (1) ◽  
pp. 406-420 ◽  
Author(s):  
Gwénaëlle Salaün ◽  
Helle A. Pedersen ◽  
Anne Paul ◽  
Véronique Farra ◽  
Hayrullah Karabulut ◽  
...  
Keyword(s):  
Surface Wave ◽  
High Resolution ◽  
Upper Mantle ◽  
Surface Wave Tomography ◽  
Mantle Structure ◽  
Upper Mantle Structure ◽  
Wave Tomography

scholarly journals Shear velocity structure of the crust and upper mantle of Madagascar derived from surface wave tomography

2017 ◽  
Vol 458 ◽  
pp. 405-417 ◽  
Author(s):  
Martin J. Pratt ◽  
Michael E. Wysession ◽  
Ghassan Aleqabi ◽  
Douglas A. Wiens ◽  
Andrew A. Nyblade ◽  
...  
Keyword(s):  
Surface Wave ◽  
Upper Mantle ◽  
Velocity Structure ◽  
Shear Velocity ◽  
Surface Wave Tomography ◽  
Crust And Upper Mantle ◽  
Wave Tomography
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