The granulometric composition of terrigenous deep-sea sediments provides information on the current speed if certain frame conditions are fulfilled. In particular, these include current transport to be the only transport process. In the high latitudes this type of investigation is impaired due to the influence of ice-rafted debris (IRD) that is contaminating the current sorted grain-size fractions. In this study a new method is presented that addresses this problem by setting the ice-rafted sand in relation to the silt of both, current and ice-transported origin. Deviations from the resulting regression function are then used to determine the behaviour of the silt mean grain size as a function of current speed largely independent from IRD bias. The study is based on sediments from the Yermak Plateau, Arctic Ocean, a region influenced by IRD brought with the south-headed Transpolar Drift and by north-directed bottom currents. The IRD correction results in displaying changes of current speed at much higher clarity; climate forcing of the currents becomes more evident. For example, the 8,200 cold event shows up as a major event in the corrected record whereas it is hardly visible in the original record.
AWI Organizations > Geosciences > Marine Geology and Paleontology