Ice sheets cover about 16 million km2 of the Earth's surface today. During the last glacial maximum, about 20,000 yr ago, ice covered about double this area, contributed to mainly by the growth of the North American and Eurasian ice sheets and the advance of the Antarctic and Greenland ice sheets across the adjacent continental shelves (Clark & Mix, 2002). Significant portions of the margins of these contemporary and past ice sheets terminate in marine waters. From this ice-ocean interface, icebergs, meltwaters and the sediments they transport, are released into the oceans. About 10% of modern oceans are affected directly by glacier-derived sediments and sedimentation, and this area approximately doubled at the last glacial maximum.
The continental margins of high- and mid-latitudes, that is the continental shelves, slopes and deep-sea basins beyond (Fig. 30.1), therefore contain a record of both present and past glacimarine processes and products. Here, we describe the large-scale sedimentary architecture of these glacier-influenced margins, together with inferences that can be made from this evidence concerning the nature of past ice-sheet flow and environmental change.
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