The Influence of 5000 year-old and Younger Glacial Mass Variability on Present-day Crustal Rebound in the Antarctic Peninsula

Assessment of Antarctic rebound is complicated by two issues: (1) The total ice volume at Last Glacial Maximum is contentious, with estimates ranging from just a few meters to several tens of meters of equivalent eustatic sea level rise. (2) The late Holocene mass budget is also uncertain. Space-based geodesy may provide important data in the coming years for estimating the recent ice mass balance state of Antarctica. Toward this end, GPS has an important role for isolating the solid earth movements that are associated with postglacial rebound. Here we provide numerical examples of vertical motions that are predicted by coupling realistic glacial load histories to 20th century ice mass imbalance estimates for the Antarctic Peninsula. The main complexity revealed by these examples is the striking difference among predictions that have an oscillatory mass change during the last 5000 to 50 years, as opposed to those having a continuous (non-oscillatory) mass drawdown of the grounded ice sheet.