Surface vector mapping of magnetic anomalies over the Moon using Kaguya and Lunar Prospector observations

Abstract

We have provided preliminary global maps of three components of the lunar magnetic anomaly on the surface applying the surface vector mapping (SVM) method. The data used in the present study consist of about 5 million observations of the lunar magnetic field at 10-45 km altitudes by Kaguya and Lunar Prospector. The lunar magnetic anomalies were mapped at 0.2°equi-distance points on the surface by the SVM method, showing the highest intensity of 718 nT in the Crisium antipodal region. Overall features on the SVM maps indicate that elongating magnetic anomalies are likely to be dominant on the Moon except for the young large basins with the impact demagnetization. Remarkable demagnetization features suggested by previous studies are also recognized at Hertzsprung and Kolorev craters on the farside. These features indicate that demagnetized areas extend to about 1-2 radii of the basins/craters. There are well-isolated central magnetic anomalies at four craters: Leibnitz, Aitken, Jules Verne, and Grimaldi craters. Their magnetic poles through the dipole source approximation suggest occurrence of the polar wander prior to 3.3-3.5 Ga. When compared with high-albedo markings at several magnetic anomalies such as the Reiner Gamma anomalies, three-dimensional structures of the magnetic field on/near the surface are well correlated with high-albedo areas. These results indicate that the global SVM maps are useful for the study of the lunar magnetic anomalies in comparison with various geological and geophysical data.

Investigating Sources of Mercury's Crustal Magnetic Field: Further Mapping of MESSENGER Magnetometer Data

“…Because Mercury has some similarities to the Moon (heavily cratered surface, reducing geochemical conditions), some aspects of lunar observational evidence should be considered. In particular, anomalies are observed within a number of Nectarian‐aged lunar impact basins such as Crisium, Moscoviense, and Leibnitz (Halekas et al, ; Hood, ; Kim et al, ; Oliveira et al, ; Tsunakawa et al, ). Weaker anomalies within the Imbrian‐aged Schrödinger and Imbrium basins have also been identified (Hood & Spudis, ).…”

Reiner Gamma: A Magnetized Elliptical Disk on the Moon

“…Arrows show the magnetic declination of the source body inferred from previous studies. K05 is Kurata et al (), HGB12 is Hemingway and Garrick‐Bethell (), T14 is Takahashi et al (), and T15 is Tsunakawa et al (). The LP and K suffixes apply to Lunar Prospector and Kaguya single dipole inversions, respectively.…”

Magnetic anomalies in the Imbrium and Schrödinger impact basins: Orbital evidence for persistence of the lunar core dynamo into the Imbrian epoch

“…Maps of the lunar nearside constructed using LP ER data show weak anomalies within the rim of Imbrium [ Halekas et al , , Plate 1; Halekas et al , , Figures 1 and 5; Mitchell et al , , Figures 4 and 5; Halekas et al , , Figure 5]. More recent global mapping of LP and KG magnetometer data also show weak anomalies within the Imbrium rim [ Purucker and Nicholas , , Figure 6; Tsunakawa et al , , Figures 2 and 4]. While the locations and relative amplitudes of these anomalies are often inconsistent from one map to another, some consistencies can be found.…”