Deep Radiostratigraphy Constraints Support the Presence of Persistent Wind Scouring Behavior for More Than 100 Ka in the East Antarctic Ice Sheet

Abstract

The characterization of unconformities in wind-scoured areas of the Antarctic Ice Sheet (AIS) is important for the accurate estimation of Antarctic mass balance and can provide constraints on climate models. Here we apply radar data collected by the Chinese National Antarctic Research Expedition in the vicinity of the Dome A region in East Antarctica to trace six isochronous internal reflecting horizons. We identify 39 unconformities and map englacial stratigraphy 500 m below the ice surface through cross-validation among the data from several austral summer campaigns using different ice-penetrating radars. By estimating erosion time of buried unconformities using a one-dimensional ice flow model along local ice flowlines, we identify persistent wind-scoured zones on the scale of ten thousand years. We identify the earliest truncated climatic record through interpretation of the radar images and find that erosional activity can be dated back to approximately 100,000 years before present; all of the persistent wind scouring behaviors we present here began during the Last Interglacial- Last Glacial (128 ~ 10 ka B.P.). High-resolution records such as this that reveal englacial unconformities and englacial structural characteristics associated with erosion contribute to improved understanding of climate variability and ice sheet dynamics during the Late Pleistocene.