Draping or overriding: The effect of horizontal stress gradients on internal layer architecture in ice sheets

Abstract

Internal isochronic layers in ice sheets sensed by radar show two characteristicrelationships to the basal topography: Either they override it, with layers above the crestsof rises lying essentially flat, or they drape over it, with the layers following rises andfalls in basal topography. A mechanical theory is presented which shows that overriding isthe expected behavior when topographic wavelengths are comparable with or less thanthe ice thickness, while draping occurs at longer wavelengths. This is shown withanalytical perturbation Show more