Age stratigraphy and basal properties of the East Antarctic Ice Sheet from radio-echo sounding measurements : and inferences about ice dynamics

Abstract

The ice sheet internal structure is an imprint of its history and dynamics, and, additionally, the ice and enclosed air provide valuable information about the past climate. An established continent-wide stratigraphy can constrain both paleo-climate reconstructions and ice-flow models. In this study, the internal stratigraphy and basal properties of the East Antarctic Ice Sheet (EAIS) are inferred from radio-echo sounding (RES) measurements and interpreted with respect to ice dynamics. The first part evaluates the compatibility of multiple RES data sets and investigates the physical cause for RES internal reflections, ensuring their isochronicity. These reflections are used to map the age-depth stratigraphy of the EAIS. The depth distribution of paleo surfaces provides first estimates about accumulation-rate distribution and maximum age of the ice. The third part analyzes the roughness of the EAIS' base. Relationships between basal roughness, ice-flow speed and basal temperatures are observed, which could serve as a method to infer the basal thermal condition or validate modeled temperate-bed locations.