How sensitive are relative sea-level records across the Antarctic Peninsula to late-Holocene glacial fluctuations?

Abstract:

Traditional models of glacial-isostatic adjustment through the Holocene across much of Antarctica suggest a record of exponentially decreasing rates of relative sea-level (RSL) fall. Such models propose little to no effect of late Holocene ice-mass changes on RSL across the Antarctic Peninsula, largely reflecting an assumed relatively strong Earth rheology. However, increasing evidence of glacial oscillations across many parts of Antarctica, including the Antarctic Peninsula, as well as the presence of a relatively weak rheology beneath West Antarctica are beginning to mount. What impact, if any, have these oscillations and a relatively weak Earth rheology had on Antarctic sea-level records? In this study we review new and existing relative-sea level records from Joinville Island along the eastern tip of the Antarctic Peninsula, the Western Antarctic Peninsula, and the South Shetland Islands that suggest abrupt increases in the rate of RSL fall through the late Holocene. We propose that these abrupt increases in the rate of RSL fall mark the solid earth response to periods of accelerated glacial retreat during the Holocene. In addition, we examine ground-penetrating radar profiles through raised beaches across the Antarctic Peninsula that also point to periods of relative sea-level rise during the Late Holocene, possibly in response to local glacial advances. These RSL reconstructions point to a dynamic Earth beneath the Antarctic Peninsula supporting recent assertions of a weak rheology underlying this part of Western Antarctica.