Geomagnetic Studies
High-performance computing has allowed the first realistic simulations of
the convective dynamo that creates the geomagnetic field. These numerical
simulations have been used to explore the possible consequences of changing
thermal boundary conditions at the core-mantle boundary and have made
intriguing predictions about the possible connections between the geodynamo and
mantle dynamics. Analyses of the historical magnetic field show long-standing
features that persist for at least hundreds of years, and comparison with the timeaveraged field over 5 million years reveals intriguing similarities ( Figure 2.16 ).
The newest generation of paleomagnetic instrumentation provides measurements
of an unprecedented quality. Coupled with careful field work, these new
instruments permit reliable estimates of field paleointensity. Short-term variations
in both direction and intensity not only furnish a means for making highresolution stratigraphic correlations, but also place important constraints on the
processes that generate the geomagnetic field. In particular, the new data can be
used to develop a more detailed understanding of magnetic field reversals, and
the time-averaged field can be used to understand long-term deviations from an
axial dipole. Finally, extending the geographical coverage of high-resolution
paleomagnetic records obtained from sediments and igneous rocks is critical for
testing predictions made by core dynamo models. Drilling into highsedimentation-rate, anoxic basins provides the best data for attaining these goals,
although paleomagnetic studies of continental rocks will also yield valuable
measurements.
SCIENCE OPPORTUNITIES
77
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.
High-performance computing has allowed the first realistic simulations of
the convective dynamo that creates the geomagnetic field. These numerical
simulations have been used to explore the possible consequences of changing
thermal boundary conditions at the core-mantle boundary and have made
intriguing predictions about the possible connections between the geodynamo and
mantle dynamics. Analyses of the historical magnetic field show long-standing
features that persist for at least hundreds of years, and comparison with the timeaveraged field over 5 million years reveals intriguing similarities ( Figure 2.16 ).
The newest generation of paleomagnetic instrumentation provides measurements
of an unprecedented quality. Coupled with careful field work, these new
instruments permit reliable estimates of field paleointensity. Short-term variations
in both direction and intensity not only furnish a means for making highresolution stratigraphic correlations, but also place important constraints on the
processes that generate the geomagnetic field. In particular, the new data can be
used to develop a more detailed understanding of magnetic field reversals, and
the time-averaged field can be used to understand long-term deviations from an
axial dipole. Finally, extending the geographical coverage of high-resolution
paleomagnetic records obtained from sediments and igneous rocks is critical for
testing predictions made by core dynamo models. Drilling into highsedimentation-rate, anoxic basins provides the best data for attaining these goals,
although paleomagnetic studies of continental rocks will also yield valuable
measurements.
SCIENCE OPPORTUNITIES
77
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.