Lateral Variations in Lunar Crustal Thickness Inferred From Apollo Seismic and GRAIL Gravity Data

Abstract The internal structure of the Moon is key to understanding its formation, evolution, and bulk composition. In particular, determining the structure of the crust–mantle interface (Moho), including its lateral variations, is of significant importance, but current knowledge is still insufficient to fully constrain it. To address this, we used seismic wave arrivals from impact events, which yield constraints on the crust at both the impact sites and the Apollo stations, to invert for local crustal thickness. Based on a series of assumed crust and mantle density models, we compared Moho depths inferred from global gravity recovery and interior laboratory gravity data with those from seismic observations. Although the gravity‐derived results broadly capture the overall Moho relief, local discrepancies remain, with differences reaching up to 10 km in the vicinity of the Apollo 17 Saturn IVB impact site. These results may reflect regional geological anomalies and highlight the importance of incorporating multiple seismically constrained crustal thickness estimates as anchors in gravity inversions. Using seven seismic anchor points and assuming an upper mantle velocity of 7.68 , an upper mantle density of 3,280 , and a crustal density of 2,693 , we obtain an average lunar crustal thickness of 43.6 1.9 km. The findings also provide valuable guidance for future global 3D modeling of the Moon.