Understanding the total volume of the Moon’s crust is essential to reconstruct its formation and geological evolution.
Although measurements of the Moon’s topography and gravity field, such as those from the GRAIL mission, have revealed the relative lateral variations in crustal thickness, they do not provide direct estimates of the total crustal volume.
Seismic methods, which could help resolve this, are complicated by the fact that the Moon’s interior strongly scatters seismic waves, making traditional analysis difficult.
In this study, we turn this challenge into an opportunity by using the scattered wavefield to search for seismic reflections from the base of the lunar crust.
Among all the Apollo seismic stations, station 16, located in the lunar highlands, shows the clearest evidence of such reflections. These signals suggest a crustal thickness of about 53 km beneath that site.
Our findings also indicate that the seismic properties of the Moon’s crust vary significantly across different regions.
This approach demonstrates how scattered seismic waves can be harnessed to improve our understanding of the deep crustal structure of the Moon.