The quantitative relationship between small impact crater morphology and regolith depth

Small impact craters (∼10–300 m) that encounter a strength transition in the target (like a regolith over bedrock) have unique morphologies. Previous studies have used these morphologies as indicators of regolith depth. This paper reports on several new analyses that expand our understanding of the quantitative relationship between small crater morphology and target layering. I describe three practical situations where the application of the updated method is ambiguous because the specific relationship between the target layering and the crater morphology has never been analyzed. In order to resolve the ambiguity, I report on new analyses of computer models and lunar data that demonstrate how the dimensions of the crater shape relate to layer depth. I also analyze the boundary conditions under which the crater-layering relationship will enable determination of layering depth. Finally, in light of the greater understanding of the crater-layering relationship, I discuss the possible application of this method to Mars.