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| Titel |
Structure and Heterogeneity of the Martian Crustal Magnetic Field |
| VerfasserIn |
Kevin Lewis, Frederik Simons |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250057539
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| Zusammenfassung |
| Although the planet Mars no longer possesses an internal dynamo, its
crustal rocks retain strong remanent magnetization thought to have
been induced by an ancient core-sourced field. The strength and
distribution of the observed crustal field is extremely heterogeneous.
The strongest anomalies are found in the Terra Cimmeria region of the
southern hemisphere, where large, correlated structures form several
east-west trending lineations of alternating polarity [Connerney,
1999]. While several areas of the planet appear to have been
demagnetized, including large impact basins and the Tharsis volcanic
province, the distribution of the field is generally poorly correlated
with surface geologic structures. Beyond the spatial pattern of
crustal magnetization, the magnetic power spectrum can provide
information about the distribution of the underlying sources. We use
the spatiospectral localization technique of Wieczorek and Simons
[2005], and Dahlen and Simons [2008] to isolate the magnetic power
spectrum of specific areas of the martian surface. Localized spectral
estimates, along with their calculated variances, allow us to examine
the significance of observed variations between distinct regions of
the planet, and to evaluate the validity of analyses which operate on
the whole sphere. Approximate strengths and depths of the
magnetic sources within the crust are calculated for tiled windows
across the planet using idealized magnetic source models. We observe
a wide range of estimated parameters, indicative of the spatial
diversity of the martian field. We will present these results in the
context of martian crustal formation and evolution. |
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