Thicknesses of mare basalts on the Moon from gravity and topography

摘要: A new method of determining the thickness mare basalts on Moon is introduced that made possible by high-resolution gravity data acquired from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission. Using a localized multitaper spherical-harmonic analysis, an effective density spectrum calculated provides estimate average crustal as function spherical harmonic degree. By comparing observed with one generated theoretical model, can be constrained. We assume grain known remote sensing petrologic considerations, we assign constant porosity to basalts, let both underlying crust vary. this method, total was estimated nearside hemisphere, yielding 0.74 km 1σ upper lower bounds 1.62 km 100 m, respectively. The region Marius Hills, which long-lived volcanic complex, found have thickest 2.86 km limits 3.65 1.02 km, beneath Mare Imbrium atypically high about 3000 kg m−3 interpret representing mafic, unfractured, impact melt sheet.