AuthorHalekas, J. S.
AffiliationUniv Arizona, Lunar & Planetary Lab
MetadataShow full item record
PublisherAMER GEOPHYSICAL UNION
CitationDemagnetization signatures of lunar impact craters 2002, 29 (13) Geophysical Research Letters
JournalGeophysical Research Letters
RightsCopyright 2002 by the American Geophysical Union.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractWe investigate the crustal magnetic signatures of lunar craters using Lunar Prospector (LP) electron reflectometer data. Craters of all ages often have associated magnetic lows, showing that crustal fields were present even in pre-Nectarian times (≳3.9 Ga). Magnetic lows extend to ∼2–4 crater radii, suggesting shock rather than thermal demagnetization. Younger craters are more likely to have clear and complete demagnetization signatures, suggesting that many older magnetic lows have been subsequently obscured. No size dependence is found for craters larger than 50 km in diameter, suggesting that demagnetization effects for all craters in this size range completely penetrate the magnetized layer. If shock demagnetization is responsible, this suggests an upper limit of ∼50 km for the depth of magnetization. Evidence of edge effects due to magnetization contrasts may show that strong far-side crustal fields are coherent at scales of ∼25 km.
Note6 month embargo; First published:12 July 2002
VersionFinal published version
SponsorsResearch at the University of California, Berkeley, was supported by NASA through subcontract LRI-99-101 from the Lunar Research Institute.