TY - JOUR
T1 - Seismic tomography and geochemical evidence for lunar mantle heterogeneity
T2 - Comparing with Earth
AU - Zhao, Dapeng
AU - Arai, Tomoko
AU - Liu, Lucy
AU - Ohtani, Eiji
N1 - Funding Information:
This work was partially supported by research grants ( Kiban-A 17204037 ; Kiban-S 11050123 ) from Japan Society for the Promotion of Science to D. Zhao and by the Global-COE program of the Earth and Planetary Sciences of Tohoku University . We appreciate Y. Nakamura, T. Sakamaki, J. Lei, Y. Kasaba and S. Sasaki for thoughtful discussions and Y. Yamamoto, T. Yanada and M. Tanaka for their assistance in computer graphics. Prof. Sierd Cloetingh (the Editor), Elishevah van Kooten, A. van den Berg and an anonymous reviewer provided helpful review comments and suggestions that have improved the manuscript. Some of the figures were made using GMT ( Wessel and Smith, 1998 ).
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/6
Y1 - 2012/6
N2 - We present seismic tomography and geochemical evidence for the existence of significant lateral heterogeneities in the lunar mantle and make a comparison with the Earth's heterogeneity and seismicity. The Procellarum KREEP Terrane (PKT) is a unique province on the nearside of the Moon. It constitutes only about 15% or less of the lunar surface, but appears to owe a large portion of the Moon's radioactive heat-producing elements. We found a correlation between the Thorium (Th) abundance distribution and seismic tomography of the lunar nearside. The area with high Th abundance exhibits a distinct low shear-wave velocity, and the low-velocity anomaly extends down to 300-400. km depth below the PKT, suggesting that the thermal and compositional anomaly has a depth extent of 300-400. km in the lunar mantle. The distribution of deep moonquakes shows a correlation with the seismic-velocity variations in the deep lunar mantle, similar to the earthquakes which are affected or controlled by structural heterogeneities in the terrestrial crust and upper mantle. The presence of deep moonquakes and seismic-velocity heterogeneities in the mantle implies that the interior of the present Moon may be still thermally active.
AB - We present seismic tomography and geochemical evidence for the existence of significant lateral heterogeneities in the lunar mantle and make a comparison with the Earth's heterogeneity and seismicity. The Procellarum KREEP Terrane (PKT) is a unique province on the nearside of the Moon. It constitutes only about 15% or less of the lunar surface, but appears to owe a large portion of the Moon's radioactive heat-producing elements. We found a correlation between the Thorium (Th) abundance distribution and seismic tomography of the lunar nearside. The area with high Th abundance exhibits a distinct low shear-wave velocity, and the low-velocity anomaly extends down to 300-400. km depth below the PKT, suggesting that the thermal and compositional anomaly has a depth extent of 300-400. km in the lunar mantle. The distribution of deep moonquakes shows a correlation with the seismic-velocity variations in the deep lunar mantle, similar to the earthquakes which are affected or controlled by structural heterogeneities in the terrestrial crust and upper mantle. The presence of deep moonquakes and seismic-velocity heterogeneities in the mantle implies that the interior of the present Moon may be still thermally active.
KW - Apollo missions
KW - Moon
KW - Moonquakes
KW - Procellarum KREEP Terrane
KW - Seismic tomography
KW - Thorium abundance
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U2 - 10.1016/j.gloplacha.2012.01.004
DO - 10.1016/j.gloplacha.2012.01.004
M3 - Article
AN - SCOPUS:84862776822
VL - 90-91
SP - 29
EP - 36
JO - Global and Planetary Change
JF - Global and Planetary Change
SN - 0921-8181
ER -