Late Holocene relative sea-level records from coral microatolls in Singapore

Résumé fourni par la source

Late Holocene relative sea-level (RSL) data are important to understand the drivers of RSL change, but there is a lack of precise RSL records from the Sunda Shelf. Here, we produced a Late Holocene RSL reconstruction from coral microatolls in Singapore, demonstrating for the first time the utility of Diploastrea heliopora microatolls as sea-level indicators. We produced 12 sea-level index points and three marine limiting data with a precision of < ± 0.2 m (2σ) and < ± 26 yrs uncertainties (95% highest density region). The data show a RSL fall of 0.31 ± 0.18 m between 2.8 kyrs BP and 0.6 kyrs BP, at rates between -0.1 ± 0.3 mm/yr and -0.2 ± 0.7 mm/yr. Surface profiles of the fossil coral microatolls suggest fluctuations in the rate of RSL fall: 1) stable between 2.8 and 2.5 kyrs BP; 2) rising at ~1.8 kyrs BP; and 3) stable from 0.8 to 0.6 kyrs BP. The microatoll record shows general agreement with published, high-quality RSL data within the Sunda Shelf. Comparison to a suite of glacial isostatic adjustment (GIA) models indicate preference for lower viscosities in the mantle. However, more high quality and precise Late Holocene RSL data are needed to further evaluate the drivers of RSL change in the region and better constrain GIA model parameters.

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