Fractal dimensions of rampart impact craters on MarsEjecta blanket morphologies of Martian rampart craters may yield important clues to the atmospheric densities during impact, and the nature of target materials (e.g., hard rock, fine-grained sediments, presence of volatiles). In general, the morphologies of such craters suggest emplacement by a fluidized, ground hugging flow instead of ballistic emplacement by dry ejecta. We have quantitatively characterized the shape of the margins of the ejecta blankets of 15 rampart craters using fractal geometry. Our preliminary results suggest that the craters are fractals and are self-similar over scales of approximately 0.1 km to 30 km. Fractal dimensions (a measure of the extent to which a line fills a plane) range from 1.06 to 1.31. No correlations of fractal dimension with target type, elevation, or crater size were observed, though the data base is small. The range in fractal dimension and lack of correlation may be due to a complex interplay of target properties (grain size, volatile content), atmospheric pressure, and crater size. The mere fact that the ejecta margins are fractals, however, indicates that viscosity and yield strength of the ejecta were at least as low as those of basalts, because silicic lava flows are not generally fractals.
Ching, Delwyn (Hawaii Univ. Honolulu, HI, United States)
Taylor, G. Jeffrey (Hawaii Univ. Honolulu, HI, United States)
Mouginis-Mark, Peter (Hawaii Univ. Honolulu, HI, United States)
Bruno, Barbara C. (Hawaii Univ. Honolulu, HI, United States)
September 6, 2013
January 1, 1993
Publication: Lunar and Planetary Inst., Twenty-fourth Lunar and Planetary Science Conference. Part 1: A-F
LUNAR AND PLANETARY EXPLORATION
Work of the US Gov. Public Use Permitted.
IDRelationTitle19940007055Analytic PrimarySixth Annual Workshop on Space Operations Applications and Research (SOAR 1992), volume 219940007543Analytic PrimaryTwenty-fourth Lunar and Planetary Science Conference. Part 1: A-Fvisibility_off