Vor 5300 Jahren lag der Meeresspiegel in Surinam und Guyana etwa 1m höher als heute

In einer Arbeit von Khan et al. 2017 wird die Meeresspiegelgeschichte der Karibik während der letzten 10.000 Jahre berichtet. Nach Ende der letzten Eiszeit vor 11.000 Jahren stieg der Meeresspiegel in Surinam und Guyana mit einer Rate von 11 mm pro Jahr an. Das ist etwa 5 mal schneller als heute. Im mittleren und späten Holozän (also seit 5000 Jahren vor heute), betrug der Meeresspiegelanstieg dann weniger als 2,4 mm pro Jahr. Übrigens: Vor 5300 Jahren lag der Meeresspiegel in den beiden Ländern etwa 1 m über dem heutigen Stand. Überrascht? Abstract:

Drivers of Holocene sea-level change in the Caribbean
We present a Holocene relative sea-level (RSL) database for the Caribbean region (5°N to 25°N and 55°W to 90°W) that consists of 499 sea-level index points and 238 limiting dates. The database was compiled from multiple sea-level indicators (mangrove peat, microbial mats, beach rock and acroporid and massive corals). We subdivided the database into 20 regions to investigate the influence of tectonics and glacial isostatic adjustment on RSL. We account for the local-scale processes of sediment compaction and tidal range change using the stratigraphic position (overburden thickness) of index points and paleotidal modeling, respectively. We use a spatio-temporal empirical hierarchical model to estimate RSL position and its rates of change in the Caribbean over 1-ka time slices. Because of meltwater input, the rates of RSL change were highest during the early Holocene, with a maximum of 10.9 ± 0.6 m/ka in Suriname and Guyana and minimum of 7.4 ± 0.7 m/ka in south Florida from 12 to 8 ka. Following complete deglaciation of the Laurentide Ice Sheet (LIS) by ∼7 ka, mid-to late-Holocene rates slowed to < 2.4 ± 0.4 m/ka. The hierarchical model constrains the spatial extent of the mid-Holocene highstand. RSL did not exceed the present height during the Holocene, except on the northern coast of South America, where in Suriname and Guyana, RSL attained a height higher than present by 6.6 ka (82% probability). The highstand reached a maximum elevation of +1.0 ± 1.1 m between 5.3 and 5.2 ka. Regions with a highstand were located furthest away from the former LIS, where the effects from ocean syphoning and hydro-isostasy outweigh the influence of subsidence from forebulge collapse.

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