Glacials

For the preceding two and a half million years, through the Pleistocene Epoch, the planet’s climate fluctuated between frozen stretches, called glacials, and warm interglacials.

Despite the difficulties, analysis of ice core and ocean sediment cores citation has shown periods of glacials and interglacials over the past few million years.

Furthermore, this evidence was difficult to date exactly; early theories assumed that the glacials were short compared to the long interglacials.

Geochemical evidence from rocks associated with low-latitude glacial deposits have been interpreted to show a crash in oceanic life during the glacials.

Glacials are characterized by cooler and drier climates over most of the earth and large land and sea ice masses extending outward from the poles.

Glacials are separated by "interglacials".

Glacials receive an even number; interglacials, odd.

Sediment records showing the fluctuating sequences of glacials and interglacials during the last several million years.

The advent of sediment and ice cores revealed the true situation: glacials are long, interglacials short.

The glacials in the following tables show historical usages, are a simplification of a much more complex cycle of variation in climate and terrain, and are generally no longer used.

These names have been abandoned in favor of numeric data because many of the correlations were found to be either inexact or incorrect and more than four major glacials have been recognized since the historical terminology was established.

Within a long-term ice age, individual pulses of cold climate are termed " glacial periods " (or alternatively "glacials" or "glaciations" or colloquially as "ice age"), and intermittent warm periods are called " interglacials ".