NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Cratering flow fields - Implications for the excavation and transient expansion stages of crater formationTheoretical depths, volumes of excavation, hinge radii, ejection angles and transient structural rim uplifts are calculated, for comparison with experimental and field data from impact and explosion craters, by means of a Maxwell Z-model cratering flow field originating at non-zero depths-of-burst. It is found that the formation of a hinge, about which the coherent ejecta flap rotates at the rim of the transient crater, divides material in the flow field into ejected and downward and outward-driven portions. Ejected material originates from an excavation cavity whose geometry is distinct from that of the transient crater. The shallow depths of excavation both observed in impact and explosion craters and predicted by the Z-model flow fields imply that thickness estimates of such lunar geologic units as the maria basalts, which are determined by assuming that excavation depths are similar to (1) final or (2) transient crater depths, must be reduced by factors of two to three respectively. It is concluded that lunar basin excavation cavities exhibit proportional growth, and have maximum depths of excavation near 0.1 the diameter of the basin transient crater.
Document ID
19820038853
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Croft, S. K.
(Lunar and Planetary Institute Houston, TX, United States)
Date Acquired
August 10, 2013
Publication Date
January 1, 1980
Subject Category
Lunar And Planetary Exploration
Meeting Information
Meeting: Lunar and Planetary Science Conference
Location: Houston, TX
Start Date: March 17, 1980
End Date: March 21, 1980
Accession Number
82A22388
Funding Number(s)
CONTRACT_GRANT: NSR-09-051-001
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available