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Apollo 14 and 16 Active Seismic Experiments, and Apollo 17 Lunar Seismic ProfilingSeismic refraction experiments were conducted on the moon by Apollo astronauts during missions 14, 16, and 17. Seismic velocities of 104, 108, 92, 114 and 100 m/sec were inferred for the lunar regolith at the Apollo 12, 14, 15, 16, and 17 landing sites, respectively. These data indicate that fragmentation and comminution caused by meteoroid impacts has produced a layer of remarkably uniform seismic properties moonwide. Brecciation and high porosity are the probable causes of the very low velocities observed in the lunar regolith. Apollo 17 seismic data revealed that the seismic velocity increases very rapidly with depth to 4.7 km/sec at a depth of 1.4 km. Such a large velocity change is suggestive of compositional and textural changes and is compatible with a model of fractured basaltic flows overlying anorthositic breccias. 'Thermal' moonquakes were also detected at the Apollo 17 site, becoming increasingly frequent after sunrise and reaching a maximum at sunset. The source of these quakes could possibly be landsliding.
Document ID
19760018052
Document Type
Contractor Report (CR)
Date Acquired
September 3, 2013
Publication Date
April 1, 1976
Subject Category
LUNAR AND PLANETARY EXPLORATION
Report/Patent Number
NASA-CR-147760
Funding Number(s)
CONTRACT_GRANT: NAS9-5632
Distribution Limits
Public
Copyright
Public Use Permitted.

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NameType 19760018052.pdf STI