[S19-2] Apollo seismic data re-processing and future lunar seismology project

[S19-2-02] Effects of lateral variations of Moon crustal thickness on lunar seismic wave propagation: numerical study and comparing with the Apollo seismic data

^○Yanbin Wang¹, Fei Chen¹, Xianghua Jiang² (1.Department of Geophysics, Peking University, Beijing, China, 2.China Earthquake Networks Center, Beijing, China)

Most recent results derived from an analysis of lunar gravity data reveal drastic lateral variations of crustal thickness around craters on the Moon. Compared with the crustal thickness of the earth, the lunar crustal thickness has strong lateral variations, which can vary from as thin as almost zero kilometer to as thick as more than 60 kilometers. However, effects of drastic variations of crustal thickness on lunar seismic wave propagation are still not well understood.
In this study we investigate how the lateral variations of crustal thickness affect the propagation of lunar seismic waves by numerical simulations and comparing with the Apollo seismic data. We apply a 2-D staggered grid pseudospectral and finite difference hybrid method to perform numerical simulations of lunar seismic wave propagation in a laterally heterogeneous crustal Moon model. The relief of lunar crust and mantle interface is defined with different height, width and position. The effects of these factors on lunar records are discussed and revealed, respectively. We then apply our method to several 2D crustal profiles derived from the most recently published global lunar crustal model to model lunar seismic wave propagation generated from both shallow and deep moonquakes, respective. Comparing between the synthetic seismograms with the Apollo observations suggests the significant effects of drastic lateral crustal thickness variation on lunar seismic wave propagation.