Constraining Past Accumulation in Central Pine Island Glacier Basin from Radio-Echo Sounding

TY - JOUR

T1 - Constraining Past Accumulation in Central Pine Island Glacier Basin from Radio-Echo Sounding

AU - Karlsson, Nanna B.

AU - Bingham, Robert G.

AU - Rippin, David M.

AU - Hindmarsh, Richard C. A.

AU - Corr, Hugh F. J.

AU - Vaughan, David G.

PY - 2014/6

Y1 - 2014/6

N2 - The potential for future dynamical instability of Pine Island Glacier, West Antarctica, has been addressed in a number of studies but information on its past remains limited. In this study we use airborne radio-echo sounding data acquired over Pine Island Glacier to investigate past variations in accumulation pattern. In the radio-echo sounding dataset a distinctive pattern of layers was identified in the central part of the glacier basin. We use these layers as chronological identifiers in order to construct elevation maps of the internal stratigraphy. The observed internal layer stratigraphy is then compared to calculated stratigraphy from a three-dimensional ice-flow model that has been forced with different accumulation scenarios. The model results indicate that the accumulation pattern is likely to have changed at least twice since the deposition of the deepest identified layer. Additional radio-echo sounding data linked to the Byrd Ice Core provide an approximate time-scale. This time-scale suggests that the layers were deposited at the beginning of or during the Holocene period. Thus the widespread changes occurring in the coastal extent of the West Antarctic Ice Sheet at the end of the last glacial period could have been accompanied by changes in accumulation pattern.

AB - The potential for future dynamical instability of Pine Island Glacier, West Antarctica, has been addressed in a number of studies but information on its past remains limited. In this study we use airborne radio-echo sounding data acquired over Pine Island Glacier to investigate past variations in accumulation pattern. In the radio-echo sounding dataset a distinctive pattern of layers was identified in the central part of the glacier basin. We use these layers as chronological identifiers in order to construct elevation maps of the internal stratigraphy. The observed internal layer stratigraphy is then compared to calculated stratigraphy from a three-dimensional ice-flow model that has been forced with different accumulation scenarios. The model results indicate that the accumulation pattern is likely to have changed at least twice since the deposition of the deepest identified layer. Additional radio-echo sounding data linked to the Byrd Ice Core provide an approximate time-scale. This time-scale suggests that the layers were deposited at the beginning of or during the Holocene period. Thus the widespread changes occurring in the coastal extent of the West Antarctic Ice Sheet at the end of the last glacial period could have been accompanied by changes in accumulation pattern.

U2 - 10.3189/2014JoG13J180

DO - 10.3189/2014JoG13J180

M3 - Article

SN - 0022-1430

VL - 60

SP - 553

EP - 562

JO - Journal of Glaciology

JF - Journal of Glaciology

IS - 221

ER -