TY - JOUR
T1 - Local spectral variability and the origin of the Martian crustal magnetic field
AU - Lewis, Kevin W.
AU - Simons, Frederik Jozef
PY - 2012/9/1
Y1 - 2012/9/1
N2 - [1] The crustal remanent magnetic field of Mars remains enigmatic in many respects. Its heterogeneous surface distribution points to a complex history of formation and modification, and has been resistant to attempts at identifying magnetic paleopoles and constraining the geologic origin of crustal sources. We use a multitaper technique to quantify the spatial diversity of the field via the localized magnetic power spectrum, which allows us to isolate more weakly magnetized regions and characterize them spectrally for the first time. We find clear geographical differences in spectral properties and parameterize them in terms of source strengths and equivalent-layer decorrelation depths. These depths to the base of the magnetic layer in our model correlate with independent crustal-thickness estimates. The correspondence indicates that a significant fraction of the martian crustal column may contribute to the observed field, as would be consistent with an intrusive magmatic origin. We identify several anomalous regions, and propose geophysical mechanisms for generating their spectral signatures.
AB - [1] The crustal remanent magnetic field of Mars remains enigmatic in many respects. Its heterogeneous surface distribution points to a complex history of formation and modification, and has been resistant to attempts at identifying magnetic paleopoles and constraining the geologic origin of crustal sources. We use a multitaper technique to quantify the spatial diversity of the field via the localized magnetic power spectrum, which allows us to isolate more weakly magnetized regions and characterize them spectrally for the first time. We find clear geographical differences in spectral properties and parameterize them in terms of source strengths and equivalent-layer decorrelation depths. These depths to the base of the magnetic layer in our model correlate with independent crustal-thickness estimates. The correspondence indicates that a significant fraction of the martian crustal column may contribute to the observed field, as would be consistent with an intrusive magmatic origin. We identify several anomalous regions, and propose geophysical mechanisms for generating their spectral signatures.
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U2 - 10.1029/2012GL052708
DO - 10.1029/2012GL052708
M3 - Article
AN - SCOPUS:85027952659
SN - 0094-8276
VL - 39
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 17
M1 - L18201
ER -