Aerogeophysical characterization of Titan Dome, East Antarctica, and potential as an ice core target

Lucas H Beem,Duncan A Young,Sun Bo,Donald D Blankenship,Jingxue Guo,Marie G P Cavitte,Jamin S Greenbaum

doi:10.5194/tc-15-1719-2021

Abstract

Abstract. Based on sparse data, Titan Dome has been identified as having a higher probability of containing ice that would capture the middle Pleistocene transition (1.25 to 0.7 Ma). New aerogeophysical observations (radar and laser altimetry) collected over Titan Dome, located about 200 km from the South Pole within the East Antarctic Ice Sheet, were used to characterize the region (e.g., geometry, internal structure, bed reflectivity, and flow history) and assess its suitability as a paleoclimate ice core site. The radar coupled with an available ice core chronology enabled the tracing of dated internal reflecting horizons throughout the region, which also served as constraints on basal ice age modeling. The results of the survey revealed new basal topographic detail and better constrain the ice topographical location of Titan Dome, which differs between community datasets. Titan Dome is not expected to be relevant to the study of the middle Pleistocene transition due to a combination of past fast flow dynamics, the basal ice likely being too young, and the temporal resolution likely being too coarse if 1 Ma ice were to exist.

Highlights

The ice domes and ridges of Antarctica hold the best stratigraphically ordered records of past ice sheet and climate evolution
We describe new basal topography and surface elevation, determine that the basal ice age is likely younger than would be needed to capture the middle Pleistocene transition, and describe areas on the flanks of Titan Dome that may have previously experienced faster flow than at present
The surface altimetry collected here is sparse and cannot explicitly constrain the location of the Titan Dome, but the dome location in the Bamber et al (2009) digital elevation models (DEMs) was used in survey planning and corresponds to the location of highest elevation observed in this survey

Summary

Introduction

The ice domes and ridges of Antarctica hold the best stratigraphically ordered records of past ice sheet and climate evolution. Identifying coring locations to study the middle Pleistocene transition has primarily been the result of modeling efforts that find regions that have ice dynamic and thermodynamic stability suitable to allow for both 1.5 Ma of ice survival and the existence of a well-preserved ice stratigraphy One such effort used a one-dimensional thermodynamic model to find where the bed is sufficiently cold to prevent present-day basal melting (Van Liefferinge and Pattyn, 2013). With their model results and the additional criteria of present-day slow flow of less than 2 m yr−1 and ice thickness greater than 2000 m, they identified regions with increased likelihood for the recovery of an ice core dating to the middle Pleistocene transition (Fig. 1). For the regions near Titan Dome (Fig. 1), the boundaries are consistent

Methods

Results

Discussion

Conclusion