Ice deformation in the vicinity of the ice-core site at Taylor Dome, Antarctica, and a derived accumulation rate history

Abstract

AbstractKnowledge of ice flow and strain rate in the vicinity of the Taylor Dome (East Antarctica) ice-core site enhances interpretation of the paleoclimate information from the ice core. We measured surface ice motion by repeated optical and GPS surveys of a network of 253 markers. We developed a robust data reduction method that uses least squares based on singular value decomposition, to simultaneously calculate positions and velocities of these markers in a geocentric coordinate system. Constrained by these surface velocities, we used a finite-element model to compute the modern ice velocity field at depth. As the geometry of Taylor Dome appears to have been steady through the Holocene, we used particle paths from a steady-state model to track ice particles to the ice core from their points of origin on the surface. By removing the effects of path-dependent vertical strain, we derived past accumulation rates at the origin points of those particle paths from measured layer thicknesses in the ice core. Comparison with accumulation rates estimated from concentrations of10Be and SO4in the core suggests that significant amounts of snow were lost by wind scouring during the Last Glacial Maximum and at ~50kyr BP.