A eustatic sea level rise around could plausibly be solely explained by a North American source. On the other hand, if the eustatic sea level rise was larger and closer to , a significant fraction of the meltwater that caused it likely came from the Antarctic Ice Sheet. Ice sheet modelling work suggests that the abrupt onset of the Bølling-Allerød (B-A) may have triggered the separation of the Cordilleran ice sheet and Laurentide Ice Sheet (and the opening of the ice-free corridor) producing a major contribution to meltwater pulse 1A from the North American ice sheet. A contribution of around in 350 years to meltwater pulse 1A from the Antarctic Ice Sheet could have been caused by Southern Ocean warming. Besides the North American and Antarctic Ice Sheet, the Fennoscandian and Barents Sea Ice Sheet could also have contributed to meltwater pulse 1A. Mississippi River meltwater flood events In the case of the Mississippi River, the sediments of the Louisiana continental shelf and slope, including the Orca Basin, within the Gulf of Mexico preserve a variety of paleoclimate and paleohydrologic proxies. They have been used to reconstruct both the duration and discharge of Mississippi River meltwater events and superfloods for the Late glacial and postglacial periods, including the time of meltwater pulse 1A. The chronology of flooding events found by the study of numerous cores on the Louisiana continental shelf and slope are in agreement that the timing of meltwater pulses. For example, meltwater pulse 1A in the Barbados coral record matches quite well with a group of two Mississippi River meltwater flood events, MWF-3 (12,600 radiocarbon years ago); and MWF-4 (11,900 radiocarbon years ago). In addition, meltwater pulse 1B in the Barbados coral record matches a cluster of four Mississippi River superflood events, MWF-5, that occurred between 9,900 and 9,100 radiocarbon years ago. The discharge of water coursing down the Mississippi River during meltwater flood MWF-4 is estimated to have been 0.15 sverdrups (million cubic meters per second). This discharge is roughly equivalent to 50% of the global discharge during meltwater pulse 1A. This research also shows that the Mississippi meltwater flood MWF-4 occurred during the Allerød oscillation and had largely stopped before the beginning of the Younger Dryas stadial. The same research found an absence of meltwater floods discharging into the Gulf of Mexico from the Mississippi River for a period of time following meltwater flood MWF-4, known