Research perspectives of sediment waves and drifts: Monitors of global change in deepwater circulation

• Published in: Paleoceanography
• Main Authors: Mienert, Jürgen, Flood, R.D., Dullo, Wolf-Christian
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU (American Geophysical Union) 1994
• Subjects: ice core; North Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/1660/; https://oceanrep.geomar.de/id/eprint/1660/1/scan_2016-07-29_10-50-24.1.pdf; https://doi.org/10.1029/94PA02117

The purpose of this special section in Paleoceanography is to present interdisciplinary approaches for contributing to the reconstruction of ocean circulation and its response to climate changes. A high-priority objective for understanding the causes and mechanisms of climate change is the monitoring of past ocean circulation and oceanic heat and nutrient transport. Lehman and Keigwin [1992] have shown that cooling, for example, during the younger Dryas event, may have culminated in a cessation of the oceans conveyor circulation. The cooling in the North Atlantic was apparently the result of reduced northward heat transport in the upper water masses of the North Atlantic conveyor belt. In contrast, intervals with a strong surface and deepwater circulation were marked by a high northward heat transport. For the understanding of the causes and the timing of such rapid,highfrequency events, marine records of high deposition ratecores are needed. These cores should provide evidence for changes in abyssal circulation and heat transport, as well as arecord of surface and deepwater characteristics. The sediment drifts of the North Atlantic and in other ocean basins are one of the major targets for the recovery of sediments with high deposition rates (>10 cm/kyr) and for reconstructing the role of both intermediate and deepwater production in the conveyor belt, that is drawing low-latitude heat northward. We stress the need for international programs targeting high deposition rate areas on sediment drifts and sediment waves in order to understand (1) the evolution of the conveyor belt and (2) its dynamics and variability. The North Atlantic, where sediment drifts are concentrated, will provide ideal study areas with time resolutions comparable to those of ice core records but with records linked directly to the record of changing bottom water flow. Therefore one can address the changes in circulation, heat and carbon budget on high and ultrahigh resolution records.