The patterns and mechanisms of rapid climate change are important, exciting and still unresolved questions. One connection that appears to be inescapable is that deep and shallow ocean circulation components are both intimately involved in the climate system's capacity for rapid change. And climate models are in general agreement about the most important factors in North Atlantic (and global) climate change. One of the important factors is the ice rafted detritus and what it could potentially tells us about the role of ice sheets and/or sea ice in abrupt climate change, particularly with regard to fresh water connections to ocean circulation. The North Atlantic is a key area for study of abrupt climate change. Dansgaard-Oeschger events were first identified in Greenland ice cores and then correlated to North Atlantic records and beyond. An important aspect of the North Atlantic's role in abrupt climate change is related to ice sheet-ocean-atmosphere connections, which are most profoundly seen in high resolution deep sea records that include censuses of IRD (ice rafted detritus). IRD is an important archive of ice sheet behavior, and capitalizing on its message requires characterizing the major potential contributors as well as tracking their distribution in the region. The proposed work has three complementary components: to investigate when in the past 500,000 years HS Heinrich Events occurred, to characterize other potential IRD contributors in order to better assess relative timing of ice sheet activity, and to create maps at several significant time slices in order to use the pattern of compositional variability to ground-truth the provenance interpretations as well as to document surface current patterns at these times.
Cross Cutting Themes:
Comer Science and Education Foundation