Glacial terminations and rates of sea-level rise

Description

Glacial terminations in the late Pleistocene are notable for their high rates of sea-level rise. Occurring ~340 thousand years before the present (kyr BP), Termination IV (T-IV) stands out as a significant one, during which sea-level rise rates exceeded 4 meters per century. The underlying causes of such rapid deglaciation during T-IV, however, remain poorly understood due to limited absolute age constraints on marine records. We present new, radiometrically dated speleothem records obtained from Bàsura cave in northern Italy from 320 to 380 kyr BP. By transferring the speleothem-based chronology to the co-registered marine and terrestrial changes within the same sample set, we gain valuable insights into the dynamics of T-IV in the North Atlantic and Mediterranean regions. Our findings reveal that the maximum sea-level rise rates during T-IV were not synchronous with the major millennial-scale climate shifts, but rather linked to the initial phase of the subsequent interglacial period, characterized by abrupt warming in the North Atlantic. We will discuss our findings from T-IV in the context of other glacial terminations to shed light on the processes that control the high rates of sea level rise at glacial-interglacial transitions.

Abstract

International audience

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