8.2 ky event associated with high precipitation in the eastern Caribbean
Abstract
We present data from speleothems collected in Venezuela and Puerto Rico showing that the eastern Caribbean was anomalously moist during the 8.2ka event. Evidence from high-resolution analyses of Greenland ice core (GISP2) shows that at the same time northern Europe and the north Atlantic were cooler by 3 - 6° C. The trigger for the 8.2ka event is thought to be pulsed meltwater discharges from a multi-event drainage of proglacial lakes associated with the decaying Laurentide Ice Sheet margin. The meltwater apparently slowed the thermohaline circulation decreasing warmth to northern Europe. At the same time moisture transfer to the northern latitudes may have slowed resulting in the observed lower latitude precipitation patterns. The eastern Caribbean seems to be especially sensitive to the changes in the strength of the Atlantic meridional overturning circulation (AMOC). Higher precipitation values may also have increased lowland flooding along the coastal areas of north eastern South America, already affected by early Holocene sea-level change, and are linked to social territory reshuffling which stimulated the earliest migrations into the Caribbean Archipelago shortly afterwards. Our age models based on precise MC-ICPMS 230Th/U-dating indicate that the eastern Caribbean stalagmites all grew at about the same rate of 15 cm through the 8.2 ka event, much faster than during any other growth period, except today when they are also growing at an accelerated rate.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMPP31B1870W
- Keywords:
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- 4901 PALEOCEANOGRAPHY Abrupt/rapid climate change;
- 4936 PALEOCEANOGRAPHY Interglacial;
- 4958 PALEOCEANOGRAPHY Speleothems;
- 4870 OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL Stable isotopes