Sea-level fingerprinting technique: A window into meltwater pulse 1 A and constraints from Antarctica

Abstract

A global event known as Meltwater Pulse 1 A (MWP-1 A) during the last deglaciation contributed to sea level rise by 10 % in just over 0.3 ka. Different methods are being adopted to understand the source of meltwater pulses. This article provides a review of the sea-level fingerprinting technique and its application in understanding meltwater pulses with a specific focus on MWP-1 A. Sea level fingerprinting involves comparing melting scenarios to sea-level records to identify the sources of meltwater. The analysis reveals that a significant contribution from Antarctica results in larger sea-level spikes at multiple locations, while a single North American source would lead to larger spikes at specific locations. The technique takes into account factors such as glacio-geological evidence, ice-sheet changes, and Earth's visco-elastic rebound. However, the lack of precise field data limits the ability to fully constrain the source of meltwater pulses. Evidences from Antarctica suggest that while the ice sheet played a critical role in MWP-1 A, its precise contribution remains uncertain due to the complexity of ice dynamics. Deep sea sediment records, glacio-geological data and ice-core investigations indicate episodic ice-sheet collapse, particularly in marine-based sectors such as the Weddell Sea. Recent advancements in numerical modelling and geophysical reconstructions have improved our understanding of Antarctic contributions; however, significant uncertainties remain. This review highlights the need for further integration of high-resolution sediment core data, improved ice-sheet modelling, and expanded geographic coverage of fingerprinting sites to refine the estimates of MWP-1 A contributions. The insights gained from understanding past rapid sea-level rise events are crucial for predicting future sea-level changes in response to ongoing global warming and ice-sheet instability. Furthermore, these findings have significant implications for policy-making, as understanding ice-sheet dynamics and their impact on global sea levels is essential for developing effective climate adaptation and mitigation strategies.