Relative Sea Level and Abrupt Mass Unloading

TL;DR

This study models how an abrupt mass unloading of 30 km3 caused measurable uplift and sea-level changes in Barbados, linking these to past climate events like meltwater pulses and the Younger Dryas.

Contribution

It demonstrates that isostatic adjustment from sudden mass unloading can explain observed uplift rates and sea-level jumps, providing insights into past climate-related sea-level variations.

Findings

Unloading of 30 km3 caused ~0.45 mm/yr uplift variation.

Sea-level jump of 4.8 m linked to meltwater pulse MWP-1B.

Uplift and sea-level changes occurred within 150-300 years of climate events.

Abstract

Relative sea level records climatic change as well as vertical land movement. In Barbados, uplift variation is necessary to interpret one of the most complete coral reef records. Here we show that an abrupt mass unloading of 30 km3 caused an uplift variation of ~0.45 mm/yr using a modelling approach. Simulations have been conducted for different volumes and elastic thicknesses. Isostatic adjustment in relation with an abrupt mass unloading explains the observed uplift rate increased from 0.34 mm/yr to 0.8 mm/yr that occurred 11.2 kyr ago. The reconstructed sea-level curve highlights a sea-level jump of 4.8 m, with a delay of 150 yr from the termination of Younger Dryas cold event and 300 yr before the abrupt mass unloading. This sea-level jump corresponds to meltwater pulse MWP-1B and is not an artefact. A stagnation of 500 yr occurred from 12 to 11.5 kyr BP. Relative sea level records are useful to detect past landslides and erosion. Accurate analysis and reconstruction of sea-level permits to determine sea-level abrupt rise caused by climate warming during the last thousand years.