Acoustic fluidization and the scale dependence of impact crater morphology
Abstract
A phenomenological Bingham plastic model has previously been shown to provide an adequate description of the collapse of impact craters. This paper demonstrates that the Bingham parameters may be derived from a model in which acoustic energy generated during excavation fluidizes the rock debris surrounding the crater. Experimental support for the theoretical flow law is presented. Although the Bingham yield stress cannot be computed without detailed knowledge of the initial acoustic field, the Bingham viscosity is derived from a simple argument which shows that it increases as the 3/2 power of crater diameter, consistent with observation. Crater collapse may occur in material with internal dissipation Q as low as 100, comparable to laboratory observations of dissipation in granular materials. Crater collapse thus does not require that the acoustic field be regenerated during flow.
- Publication:
-
Lunar and Planetary Science Conference Proceedings
- Pub Date:
- November 1983
- DOI:
- 10.1029/JB088iS02p0A830
- Bibcode:
- 1983LPSC...13..830M
- Keywords:
-
- Acoustic Excitation;
- Collapse;
- Lunar Craters;
- Planetary Craters;
- Plastic Flow;
- Shock Heating;
- Energy Dissipation;
- Excavation;
- Geomorphology;
- Meteorite Craters;
- Projectile Cratering;
- Rock Mechanics;
- Lunar and Planetary Exploration;
- CRATERS;
- MORPHOLOGY;
- IMPACTS;
- CRATERING;
- SCALING;
- MULTI-RING BASINS;
- ACOUSTIC FLUIDIZATION;
- MODELS;
- PARAMETERS;
- EXPERIMENTS;
- VISCOSITY;
- STRESS;
- COLLAPSE;
- FLOW;
- RHEOLOGY;
- DIAGRAMS;
- CALCULATIONS;
- DIAMETER;
- Planets;
- Planetology: Surfaces of planets;
- Planetology: General or miscellaneous;
- Earth Science