MARGINNOTE ALTERNATIVE PLUS

This not only increases the absolute value of the apparent “mean size” within the 10-63 μm terrigenous silt fraction, but it may also affect the apparent pattern of relative changes in the coarseness of the sortable-silt fraction along the core. Traditionally the coarseness of this size fraction is described using an index called sortable-silt mean size (), which is an arithmetic average calculated from the differential volume or mass distribution of grains within the 10-63 µm terrigenous silt fraction, where the relative weights of the individual size bins become increasingly disproportionate, with respect to the actual number of grains within those size bins, towards the coarse end of the size range. sortable silt) fraction tends to vary independently of sediment supply in current-sorted muds in the world's oceans, with coarser sediments representing relatively greater near-bottom flow speeds. The coarseness of the 10-63 µm terrigenous silt (i.e. However, Heinrich events show slowdowns in some regions and faster flow in others. The LGM was a period of slow flow, and meltwater events usually show slowdowns as well. Decelerations in flow speed accompany Holocene coolings, while accelerations accompany warmings. It is therefore highly unlikely that the local Holocene thermal maxima are responses to increased flow of shallow currents in the adjacent ocean areas. In almost all cases Holocene flow speed maxima lag the local Holocene Thermal Maxima by between years. Models also show a Holocene east-west difference in deep-water formation with increase in the Labrador Sea and decrease in the Nordic seas. This points to control on deep water overflows by the flux of cold fresh water from Greenland and the Arctic, some of which may have come from the Pacific via the Bering Strait. The freshest/coldest deep Denmark Strait overflow recorded at Orphan Knoll, as well as Labrador Sea water flow on the slope north of the Grand Banks, also show this gradual increase. In contrast to the flows east of Greenland, those west of Greenland show a slow Holocene increase in flow. This suggests that the flow of the EGC is strongly influenced by the influx of North Atlantic water, rather than supply of fresher water from ice sheet melt or Pacific origin. There is a close similarity between the pattern of Holocene decrease in the strength of the Irminger Current inflow to the Nordic Seas and outflow recorded in the EGC and in deep overflow east of Reykjanes Ridge. Atlantic and Arctic Oceans of which >80% pass the reliability test of a correlation coefficient between sortable silt mean and percentage r > 0.5 (McCave and Andrews, 2019, Quat. We have analysed 28 cores comprising ∼2900 measured samples in the high-latitude N. A key to understanding oceanic control of Earth's climate therefore resides in establishing the changes in these high-latitude currents. The outflows east of Greenland carry a substantial amount of warm salty North Atlantic water that flows into the Nordic Seas, mixes, recirculates – much of it via the Arctic Ocean - and contributes to both shallow and deep overflows.

MARGINNOTE ALTERNATIVE PLUS

In the northern North Atlantic nutrient-rich cold Arctic Ocean outflow (of modified Atlantic water) plus Pacific and ice-melt waters flow in the East Greenland Current (EGC) and in the Baffin Island Current which feeds into the Labrador Current. Shallow ocean flows in the northern North Atlantic are of key importance in the regulation of Earth's climate.

Marginnote alternative