Warm period

from Wikipedia, the free encyclopedia
Ice core and the cold and warm periods of the Quaternary

In the history of the climate and also in geology, a warm period is a period with, on average, higher temperatures between two periods with average lower temperatures, so-called cold periods . When a warm period within an ice age is meant as it is also called interglacial or interglacial period , more rarely from interglacial period . The earth is currently in an ice age, the Cenozoic Ice Age . This in turn is divided into shorter sections of cold periods and warm periods. The current Holocene , which has ruled for about 12,000 years, is one such warm period within an ice age.

Longer periods of the earth's history with higher temperatures (roughly the length of earth periods ) are also known as warm climates . In times of warm climates there are normally no large areas of ice on earth, especially not in the polar regions.

Ice age

Ice-free polar caps represent the normal state of the earth and make up about 80 to 90 percent of the earth's history . Examples are the Cretaceous and the Paleogene (older Tertiary ). Times with icy polar caps , the Ice Age , are the exception. Today's geological period, the Quaternary , is such an ice age.

Interglacial within an Ice Age

The term warm period is just like the ice age fuzzy. One speaks better of interglacial period ( interglacial ). An interglacial can be viewed as a medium-scale climatic fluctuation of around 10,000 to 400,000 years. The Holocene , which continues to this day, is such a warm period within the current ice age, the Pleistocene Ice Age, which can be seen over longer periods of time .

The last major warm periods (in the sense of interglacial periods ) were:

  • Eem warm period with a duration of 11,000 years; in other regions - from 128,000 to 117,000 years before present Riss / Würm interglacial , Ipswichian Stage , Mikulin interglacial , Sangamonian Stage or Valdivia interglacial named
  • Holstein interglacial period 335,000 to 300,000 Jvh - in other regions of Saale-interglacial or Mindel-Riss interglacial named
  • Cromer warm period between 800,000 and 480,000 Jvh - named Günz-Mindel-Interglacial in other regions
  • Waal warm period between 1,300,000 and 900,000 Jvh
  • Tegelen warm period between 2,000,000 and 1,600,000 Jvh

Interstadial

By evaluating the oxygen isotope curve of the 18 O from boreholes in deep sea sediments and ice cores, geologically speaking, small-scale climatic fluctuations, the interstadials , can now be reached . The corresponding data situation improves the closer one approaches the present. An interstadial has an average duration of a few hundred to a few thousand years.

See also

It was followed by the so-called

Individual evidence

  1. ↑ Jürgen Ehlers: General and historical Quaternary geology . Enke, Stuttgart 1994, ISBN 3-432-25911-5 .
  2. ^ H. Murawski, W. Meyer: Geological dictionary. Spektrum Akademischer Verlag, 11th edition, 2004, ISBN 3-8274-1445-8
  3. ↑ Günz-Mindel-Interglacial - Lexicon of Biology. In: www.spektrum.de. Spectrum der Wissenschaft Verlagsgesellschaft mbH, accessed on April 2, 2019 .