GLACIAL MAXIMUM

The maximum extent of icesheet coverage during a glacial episode, or glaciation, often defined by moraine limits. The last glacial maximum (LGM), which occurred some 20,000 years ago, was so extensive in many regions that earlier limits were overridden. Hence, defining the maximum extent of ice reached during some earlier glaciations is proving difficult. However, the timings of glacial maxima are now well established from the continuous stratigraphical record preserved in marine sediment cores and ice cores.