We present a comparison of seismologically observed shear velocity and attenuation on a global scale. These observations are also compared with laboratory measurements of the same quantities made on fine-grained olivine and extrapolated to upper-mantle conditions. The analysis is motivated by recent developments in global attenuation tomography and in laboratory measurements of velocity and attenuation at seismic frequencies and upper-mantle temperatures. The new attenuation model QRFSI12 is found to be strongly anti-correlated with global velocity models throughout the upper mantle, and individual tectonic regions are each characterized by a distinct range of attenuation and velocity values in the shallow upper mantle. Overall, lateral temperature variations can explain much of the observed variability in velocity and attenuation. The seismological velocity-attenuation relationship for oceanic regions agrees with the experimental observations at depths >100 km and indicates lateral temperature variations of 150 degrees-200 degrees C at 150 and 200 km beneath the seafloor. The seismic properties of cratonic regions deviate from the experimental trends at depths <250 km, suggesting differences between oceanic and cratonic composition or water content at these depths. Globally, seismic properties shift into better agreement with the mineral-physics data at depths of similar to 125 km and similar to 225 km beneath oceans and cratons, respectively, which may indicate the base of a compositional boundary layer. (C) 2009 Elsevier B.V. All rights reserved.
Dalton, Colleen A.; Dziewonski, Adam M. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Ekstroem, Goeran Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA.
%0 Journal Article
%1 Dalton:2009
%A Dalton, C. A.
%A Ekstrom, G.
%A Dziewonski, A. M.
%C AMSTERDAM
%D 2009
%I ELSEVIER SCIENCE BV
%J EARTH AND PLANETARY SCIENCE LETTERS
%K ATTENUATION; CONTINENTAL EARTHS EAST LITHOSPHERE; MANTLE; MODEL; OLIVINE; PACIFIC POLYCRYSTALLINE RISE; SEISMIC STRUCTURE; THERMAL TOMOGRAPHY UPPER-MANTLE; WAVE
%N 1-2
%P 65--75
%R 10.1016/j.epsl.2009.04.009
%T Global seismological shear velocity and attenuation: A comparison with experimental observations
%V 284
%X We present a comparison of seismologically observed shear velocity and attenuation on a global scale. These observations are also compared with laboratory measurements of the same quantities made on fine-grained olivine and extrapolated to upper-mantle conditions. The analysis is motivated by recent developments in global attenuation tomography and in laboratory measurements of velocity and attenuation at seismic frequencies and upper-mantle temperatures. The new attenuation model QRFSI12 is found to be strongly anti-correlated with global velocity models throughout the upper mantle, and individual tectonic regions are each characterized by a distinct range of attenuation and velocity values in the shallow upper mantle. Overall, lateral temperature variations can explain much of the observed variability in velocity and attenuation. The seismological velocity-attenuation relationship for oceanic regions agrees with the experimental observations at depths >100 km and indicates lateral temperature variations of 150 degrees-200 degrees C at 150 and 200 km beneath the seafloor. The seismic properties of cratonic regions deviate from the experimental trends at depths <250 km, suggesting differences between oceanic and cratonic composition or water content at these depths. Globally, seismic properties shift into better agreement with the mineral-physics data at depths of similar to 125 km and similar to 225 km beneath oceans and cratons, respectively, which may indicate the base of a compositional boundary layer. (C) 2009 Elsevier B.V. All rights reserved.
@article{Dalton:2009,
abstract = {We present a comparison of seismologically observed shear velocity and attenuation on a global scale. These observations are also compared with laboratory measurements of the same quantities made on fine-grained olivine and extrapolated to upper-mantle conditions. The analysis is motivated by recent developments in global attenuation tomography and in laboratory measurements of velocity and attenuation at seismic frequencies and upper-mantle temperatures. The new attenuation model QRFSI12 is found to be strongly anti-correlated with global velocity models throughout the upper mantle, and individual tectonic regions are each characterized by a distinct range of attenuation and velocity values in the shallow upper mantle. Overall, lateral temperature variations can explain much of the observed variability in velocity and attenuation. The seismological velocity-attenuation relationship for oceanic regions agrees with the experimental observations at depths >100 km and indicates lateral temperature variations of 150 degrees-200 degrees C at 150 and 200 km beneath the seafloor. The seismic properties of cratonic regions deviate from the experimental trends at depths <250 km, suggesting differences between oceanic and cratonic composition or water content at these depths. Globally, seismic properties shift into better agreement with the mineral-physics data at depths of similar to 125 km and similar to 225 km beneath oceans and cratons, respectively, which may indicate the base of a compositional boundary layer. (C) 2009 Elsevier B.V. All rights reserved.},
added-at = {2010-08-12T23:06:12.000+0200},
address = {AMSTERDAM},
af = {Dalton, Colleen A. Ekstroem, Goeran Dziewonski, Adam M.},
author = {Dalton, C. A. and Ekstrom, G. and Dziewonski, A. M.},
author-address = {[Dalton, Colleen A.; Dziewonski, Adam M.] Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. [Ekstroem, Goeran] Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA.},
author-keywords = {seismology; attenuation},
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bdsk-url-1 = {http://dx.doi.org/10.1016/j.epsl.2009.04.009},
biburl = {https://www.bibsonomy.org/bibtex/23e227c1a761f05ab73d4667292fcf715/jkmacc},
cited-reference-count = {76},
date-added = {2010-04-03 14:09:27 -0600},
date-modified = {2010-04-03 14:09:27 -0600},
document-type = {Article},
doi = {10.1016/j.epsl.2009.04.009},
e-mail-address = {dalton@bu.edu},
interhash = {0058a4ed54c5b5db9aae9349707429c0},
intrahash = {3e227c1a761f05ab73d4667292fcf715},
isi = {ISI:000268438900008},
isi-document-delivery-number = {476KK},
iso-source-abbreviation = {Earth Planet. Sci. Lett.},
issn = {0012-821X},
journal = {EARTH AND PLANETARY SCIENCE LETTERS},
keywords = {ATTENUATION; CONTINENTAL EARTHS EAST LITHOSPHERE; MANTLE; MODEL; OLIVINE; PACIFIC POLYCRYSTALLINE RISE; SEISMIC STRUCTURE; THERMAL TOMOGRAPHY UPPER-MANTLE; WAVE},
language = {English},
month = Jun,
number = {1-2},
page-count = {11},
pages = {65--75},
publication-type = {J},
publisher = {ELSEVIER SCIENCE BV},
publisher-address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
reprint-address = {Dalton, CA, Boston Univ, Dept Earth Sci, Boston, MA 02215 USA.},
source = {EARTH PLANET SCI LETT},
subject-category = {Geochemistry & Geophysics},
times-cited = {1},
timestamp = {2010-08-12T23:06:14.000+0200},
title = {Global seismological shear velocity and attenuation: A comparison with experimental observations},
volume = 284,
year = 2009
}