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Lunar near-surface shear wave velocities at the Apollo landing sites as inferred from spectral amplitude ratiosThe horizontal-to-vertical amplitude ratios of the long-period seismograms are reexamined to determine the shear wave velocity distributions at the Apollo 12, 14, 15, and 16 lunar landing sites. Average spectral ratios, computed from a number of impact signals, were compared with spectral ratios calculated for the fundamental mode Rayleigh waves in media consisting of homogeneous, isotropic, horizontal layers. The shear velocities of the best fitting models at the different sites resemble each other and differ from the average for all sites by not more than 20% except for the bottom layer at station 14. The shear velocities increase from 40 m/s at the surface to about 400 m/s at depths between 95 and 160 m at the various sites. Within this depth range the velocity-depth functions are well represented by two piecewise linear segments, although the presence of first-order discontinuities cannot be ruled out.
Document ID
19810029778
Document Type
Reprint (Version printed in journal)
Authors
Horvath, P. (Marine Science Inst. Galveston, TX, United States)
Latham, G. V. (Marine Science Inst. Galveston, TX, United States)
Nakamura, Y. (Marine Science Inst. Galveston, TX, United States)
Dorman, H. J. (Texas, University Marine Science Institute, Galveston, Tex., United States)
Date Acquired
August 11, 2013
Publication Date
November 10, 1980
Publication Information
Publication: Journal of Geophysical Research
Volume: 85
Subject Category
LUNAR AND PLANETARY EXPLORATION
Funding Number(s)
CONTRACT_GRANT: NSG-7418
Distribution Limits
Public
Copyright
Other