Shallow S wave Velocity Profile from Active Source Seismic Data at the
Apollo 14 Landing Site Based on Virtual Multichannel Analysis of Surface
Waves
Abstract
We used active source seismic data at the Apollo 14 landing site to
investigate the shallow S wave velocity structure of the Moon. We
applied seismic interferometry to data from shots located between two
geophones to construct a virtual shot gather for multichannel analysis
of surface waves (MASW). We included continuous wavelet transform
processing in the MASW analysis to improve the signal-to-noise ratio of
the data before estimating the S wave velocity profile. The resultant
profile showed a regolith layer (VS = 50–70 m/s, ~3 m
thick) underlain by a harder layer (VS > 70 m/s to at least
10 m depth), similar to the profile at the Apollo 17 site. This study
demonstrated that future extraterrestrial active shallow seismic surveys
can be accomplished faster, with simpler field geometry, and using fewer
shots and receivers than past missions, thus reducing the payload and
cost of future extraterrestrial exploration missions.