Late Holocene (∼ 5 cal ka) Trends and Century‐Scale Variability of N. Iceland Marine Records: Measures of Surface Hydrography, Productivity, and Land/Ocean Interactions

We present data from five piston cores (B997-319, -321, -327, -328, and -330) collected along two of the major troughs on the N. Iceland shelf. These troughs have significantly different hydrographies associated with the influence of the North Iceland Irminger Current (Atlantic Water) and the East Iceland Current (Polar Water). Sediment accumulation rates are between 10 and 20 yrs/cm. Our paper focuses on the last 5000 yrs of record and examines mass accumulation rates (MAR g cm -2 100 yr) for carbonate, total organic carbon, and mass magnetic susceptibility. Carbonate fluxes declined in all cores, furthermore, there is a striking difference between the accumulation in Eyjafjardarall (averaging ca 0.18 g carbonate cm -2 . 100 yr) and Reykjafjardarall / Hunafloaall (averaging 0.58 g carbonate cm -2 . 100 yr). The flux of total organic carbon showed a low but persistent increase in the two Eyjafjardarall cores and lower accumulation rates than the Reykjafjardarall/Hunafloaall sites. Carbonate maximum values are dated from ca 3.8 and 2 cal ka. Correlations between the records are moderately high with r values of between 0.6 and 0.8 with minimum tweaking. Mass magnetic susceptibility variations proved similar between the fjord and inner shelf sites in the Hunafloi area and differed from the mid-shelf sites. Possible recurring periodicities occurred at around 530 and 360 yrs. These data from N. Iceland reflect an overall reduction in productivity reflecting the summer decrease in insolation at these latitudes, plus shorter-lived events which indicate multicentury variability in hydrographic conditions.