FIGURE 2.14 Seismic tomographic image of the shear velocity of the Earth’s
mantle (G. Masters, G. Laske, H. Bolton, and A. Dziewonski, The relative
behavior of shear velocity, bulk sound speed, and compressional velocity in the
mantle: Implications for chemical and thermal structure, in S. Karato, et al.,
eds., Earth’s Deep Interior: Mineral Physics and Tomography from the Atomic
to the Global Scale, Geophysical Monograph 117, American Geophysical
Union, Washington, D.C., p. 63-87, 2000). Shown are perturbations with respect
to the spherical average, where blue and red mark isovelocity surfaces for +0.6
and ` 1.0%. Top: The map view of the shallow structure reveals seismically fast
areas beneath continents and the old Pacific Ocean, whereas slow areas are
found along midocean ridges. Bottom: View of the whole mantle from south to
north (Africa to the left). Large-scale, low-velocity regions (sometimes described
as megaplumes) are surrounded by fast, relatively narrow, slablike regions that
extend across the whole mantle. The “ring” of fast velocities around the midPacific low-velocity anomaly at the bottom of the mantle is thought to be the
“graveyard of subducting slabs.” SOURCE: Reprinted with permission from P.
Tackley, Mantle convection and plate tectonics: Toward an integrated physical
and chemical theory, Science, v. 288, p. 2002-2007, 2000. Copyright 2000
American Association for the Advancement of Science. +0.6% (blue) and
`1.0% (red)
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About this PDF file: This new digital representation of the
original work has been recomposed from XML files created
from the original paper book, not from the original
typesetting files. Page breaks are true to the original; line lengths,
word breaks, heading styles, and other typesetting-specific
formatting, however, cannot be retained,
and some typographic errors may have been accidentally inserted.
Please use the print version of this publication as the authoritative
version for attribution.
mantle (G. Masters, G. Laske, H. Bolton, and A. Dziewonski, The relative
behavior of shear velocity, bulk sound speed, and compressional velocity in the
mantle: Implications for chemical and thermal structure, in S. Karato, et al.,
eds., Earth’s Deep Interior: Mineral Physics and Tomography from the Atomic
to the Global Scale, Geophysical Monograph 117, American Geophysical
Union, Washington, D.C., p. 63-87, 2000). Shown are perturbations with respect
to the spherical average, where blue and red mark isovelocity surfaces for +0.6
and ` 1.0%. Top: The map view of the shallow structure reveals seismically fast
areas beneath continents and the old Pacific Ocean, whereas slow areas are
found along midocean ridges. Bottom: View of the whole mantle from south to
north (Africa to the left). Large-scale, low-velocity regions (sometimes described
as megaplumes) are surrounded by fast, relatively narrow, slablike regions that
extend across the whole mantle. The “ring” of fast velocities around the midPacific low-velocity anomaly at the bottom of the mantle is thought to be the
“graveyard of subducting slabs.” SOURCE: Reprinted with permission from P.
Tackley, Mantle convection and plate tectonics: Toward an integrated physical
and chemical theory, Science, v. 288, p. 2002-2007, 2000. Copyright 2000
American Association for the Advancement of Science. +0.6% (blue) and
`1.0% (red)
SCIENCE OPPORTUNITIES
76
About this PDF file: This new digital representation of the
original work has been recomposed from XML files created
from the original paper book, not from the original
typesetting files. Page breaks are true to the original; line lengths,
word breaks, heading styles, and other typesetting-specific
formatting, however, cannot be retained,
and some typographic errors may have been accidentally inserted.
Please use the print version of this publication as the authoritative
version for attribution.