摘要
Re-evaluation of the post-glacial sea level derived from the Barbados coral-reef borings suggests slightly revised depth ranges and timing of melt-water pulses MWP-1A (96-76 m, 14.3-14.0 ka cal BP) and 1B (58-45 m, 11.5-11.2 ka cal BP), respectively. Ages of non-reef sea-level indicators from the Sunda Shelf, the East China Sea and Yellow Sea for these two intervals are unreliable because of the well-documented radiocarbon ( 14C) plateau, but their vertical clustering corresponds closely with MWP-1A and 1B depth ranges. Close correlation of the revised sea-level curve with Greenland ice-core data suggests that the 14C plateau may be related to oceanographic-atmospheric changes due to rapid sea-level rise, fresh-water input, and impaired ocean circulation. MWP-1A appears to have occurred at the end of Blling Warm Transition, suggesting that the rapid sea-level rise may have resulted from lateral heat transport from low to high-latitude regions and subsequent abrupt ice-sheet collapses in both North America-Europe and Antarctica. An around 70 mm a -1 transgression during MWP-1A may have increased freshwater discharge to the North Atlantic by as much as an order of magnitude, thereby disturbing thermohaline circulation and initiating the Older Dryas global cooling.
Re-evaluation of the post-glacial sea level derived from the Barbados coral-reef borings suggests slightly revised depth ranges and timing of melt-water pulses MWP-1A (96-76 m, 14.3-14.0 ka cal BP) and 1B (58-45 m, 11.5-11.2 ka cal BP), respectively. Ages of non-reef sea-level indicators from the Sunda Shelf, the East China Sea and Yellow Sea for these two intervals are unreliable because of the well-documented radiocarbon ( 14C) plateau, but their vertical clustering corresponds closely with MWP-1A and 1B depth ranges. Close correlation of the revised sea-level curve with Greenland ice-core data suggests that the 14C plateau may be related to oceanographic-atmospheric changes due to rapid sea-level rise, fresh-water input, and impaired ocean circulation. MWP-1A appears to have occurred at the end of Blling Warm Transition, suggesting that the rapid sea-level rise may have resulted from lateral heat transport from low to high-latitude regions and subsequent abrupt ice-sheet collapses in both North America-Europe and Antarctica. An around 70 mm a -1 transgression during MWP-1A may have increased freshwater discharge to the North Atlantic by as much as an order of magnitude, thereby disturbing thermohaline circulation and initiating the Older Dryas global cooling.
基金
Special thanks to Woods Hole Oceanographic Institute's post-doc scholarship support to Liu,and many thanks to Jeffrey Donnelly a and Neal Driscoll for discussion and encouragement.
