Kansan glaciation

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The Kansan Glaciation (known in the UK as the Anglian glaciation, Elster glaciation in northern Europe, and the Mindel glaciation in the Alps) was a severe glacial period in the Pleistocene. The Kansan Glaciation is generally taken as covering the period between 410,000 and 380,000 years before the present. However, with the increasing evidence that glacial maxima are shorter than previously thought, its peak is not clearly known. It is considered that the Kansan Glaciation marks the absolute maximum extent of continental ice sheets in the Quaternary.

The name, generally used only in North America, comes from the evidence that ice sheets reached as far south as Douglas County, Kansas, which is more than 300 miles further south than the limits of maximum glaciation during the Last Glacial Maximum. In Europe, ice sheets extended as far south as present-day Slovakia and London.

Because the last glacial maximum has buried most evidence of the severe Kansan glaciation, establishing environmental conditions elsewhere during this period is very difficult and can be done only via oceanic studies. These, however, indicate that the jet stream during the Kansan glaciation might have been as much as five degrees further south than it was during the last glacial maximum. (This would place it over Sonora state in Mexico and over southern Morocco in Africa).

These findings suggest strongly that the Kansan glaciation had much greater effects on the distribution of flora and fauna than more recent glacial periods. Particularly, many small ice-free refugia in North America are likely to have been completely ice-covered during this period, while in West and Central Africa, and southern Australia, most of the hypothesised forest refugia of the last ice age are likely to have lost their forest cover. Glaciers probably also occupied much larger areas in the mountains than they did at the last glacial maximum. (For instance, periglacial features in the Drakensberg suggest glaciation at some period in the Quaternary, but other evidence suggests the mountains were not glaciated during the last glacial).

The Amazon rainforest, which retained much of its present extent at the last glacial maximum, may have been constricted to a few refugia during the Kansan glaciation. These refugia have been shown to have the highest biodiversity as well as the wettest climate.