CLIMATE, ECOSYSTEM AND MELTWATER SOURCE IMPLICATIONS OF AN ARCTIC TO PACIFIC TRANSGRESSIONS, VIA THE BERING STRAIT, WITHIN THE LAST 22-7 CAL. KA. BP

The main goal of this research is to provide physical evidence(s) of reverse flow(s), from the Arctic to the North Pacific Ocean, after the Last Glacial Maximum (LGM). This is primarily essential to studies concerned with understanding how the fluctuations in strength of the Southern Ocean Wind (SOW), in conjunction with an open Bering Strait, alter the direction of water flow through the Bering Strait.

Diffuse spectral reflectance measurements from 256 surface core samples and 2 piston cores; first derivates; quotient normalization technique; varimax rotated principle component analysis; geostatistical tool-kriging; and USGS spectral library were used to extract and identify these sediments compositions (in order of importance) within the study location. These compositions are chlorite + muscovite; goethite + phycoerythrin + phycocyanin; smectite; calcite+dolomite; and illite + Chlorophyll a. Sedimentary maps of all the components were also created to determine their modern spatial patterns. This aided in the evaluation and downcore interpretation of the component most suited for this study.

The illite in illite + Chlorophyll a assemblage was deemed to be the appropriate water mass tracer for a reverse flow from the Arctic into the North Pacific; this is because of its prominence and abundance in the Mackenzie River drainage basin and on the west Arctic Sea shelf. The illite denotes these periods of melt water pulses centered at 14,000yrs BP (MWP 1A), 11,000yrs BP (MWP 1B), and 8,000yrs BP (MWP 1C). The timing of these pulses on the Bering Sea shelf enabled us to deduce 1) the initial opening of the Bering Strait and the flow direction after the LGM 2) the source of these pulses and the mechanism that might drive them through the Strait 3) the impact of these pulses on climate change and 4) the effect of these pulses on the Bering Sea shelf ecosystem.