This article needs to be updated. Please help update this article to reflect recent events or newly available information. Last update: 2008 chart and 1972 dating when it should be 2013 iugs chart and 2012 walker paper (see Holocene talk page)(May 2016)
The Würm glaciation or Würm stage (German: Würm-Kaltzeit or Würm-Glazial, colloquially often also Würmeiszeit or Würmzeit; cf. ice age), usually referred to in the literature as the Würm[1] (often spelled "Wurm"), was the last glacial period in the Alpine region. It is the youngest of the major glaciations of the region that extended beyond the Alps themselves. Like most of the other ice ages of the Pleistocene epoch, it is named after a river, in this case the Würm in Bavaria, a tributary of the Amper.[2]
Violet: The extent of the Alpine ice sheet in the Würm glaciation. Blue: The extent in earlier ice ages
The Würm ice age can be dated to about 115,000 to 11,700 years ago. Sources differ about the dates, depending on whether the long transition phases between the glacials and interglacials (warmer periods) are allocated to one or other of those periods. The average annual temperatures during the Würm ice age in the Alpine Foreland were below −3 °C (today +7 °C). That has been determined from changes in the vegetation (pollen analysis), as well as differences in the facies.[3]
The Würm glaciation (in the north: the Weichselian) in comparison with the Riss (in the north:the Saale). The glacial advances were interrupted by warmer periods during which ancient European man, the Neanderthals, as successors of homo heidelbergensis, spread out from the mountain zones and over the permafrost boundary to the north and northeast. From about 40,000 BC modern Cro-Magnon man settled these regions.The Würm glaciation, shown in ice core data from the Antarctica and GreenlandMoraines and gravel beds formed in the Würm glaciation near Leutkirch, Westallgäu, Germany, Zeil castle can be seen on the left
The corresponding ice age in North and Central Europe is known as the Weichselian glaciation, after the German name for the Vistula river. Despite the global changes in climate that were responsible for the major glaciations cycles, the dating of the Alpine ice sheet advances does not correlate automatically with the farthest extent of the Scandinavian ice sheet.[4][5] In North America the corresponding "last ice age" is called the Wisconsin glaciation.[6]
In the Gelasian, i.e. at the beginning of the Quaternary period around 2.6 million years ago, an ice age began in the northern hemisphere which continues today. Characteristic of such ice ages is the glaciation of the polar caps. After the Gelasian followed the Early, Middle and Late Pleistocene with a succession of several warm and cold periods. The latter are often called "ice ages" or "glacials", the former term often being confused with the overarching ice age period. The warm periods are called "interglacials".
Glaciers repeatedly advanced from the Alps to the northern molasse foreland and left moraines and meltwater deposits behind that are up to several hundred metres thick. Today, the Pleistocene epoch in the Alps is divided into several phases: the Biber, Danube, Günz, Haslach, Mindel, Riss and Würm glaciations. The greatest ice advance into the Alpine Foreland took place during the Riss glaciation, cf. the Saale glaciation in northern Europe.
The most recent foreland glaciation, the Würm, did not have such an extensive and solid glacial front. Nevertheless, its terminal moraines, which indicate the perimeter of the ice sheet, extend as a single tongue well into the foreland. Whilst they were hemmed in by the high mountainsides of the Alps, once these rivers of ice entered the foreland they often combined to form huge glaciers.
The moraines and gravel beds formed in the Würm glaciation are the best preserved, because since then there have been no more similar geological processes. Traces of the ice sheet have not been scoured out by later glaciers or overlaid by their sediments. This allows a more precise dating for the Würm glaciation than for earlier ice ages.
The Würm glaciation was preceded by the Eemian, which began about 126,000 years ago and lasted 11,000 years. Then there was a significant slowdown, characterized by occasional fluctuations of several degrees in average temperatures. The various advances and retreats of glaciers associated with these temperature fluctuations, are called "stadials" (periods of relatively low temperatures) and "interstadials" (relatively higher temperatures).
The Würm Glacial ended around 11,700 years ago with the beginning of the Holocene. The cold period was followed by another warming which continues today and during which the glaciers are retreating. However, even in the Holocene there have been variations in temperature and ice advances, the last one in the modern era being the so-called Little Ice Age. The Holocene is considered an "interglacial" of a larger ice age, since the poles and the high mountain areas are still glaciated.
^Whittow, John (1984). Dictionary of Physical Geography. London: Penguin, 1984, p. 586. ISBN0-14-051094-X.
^Rolf K. Meyer, Hermann Schmidt-Kaler: Auf den Spuren der Eiszeit südlich von München – östlicher Teil, Wanderungen in die Erdgeschichte, Vol. 8, ISBN978-3-931516-09-3
^Rolf K. Meyer, Hermann Schmidt-Kaler: Auf den Spuren der Eiszeit südlich von München – östlicher Teil, Wanderungen in die Erdgeschichte, Vol. 8, ISBN978-3-931516-09-3
^Sibrava, V., Bowen, D. Q, and Richmond, G. M.: Quaternary Glaciations in the Northern Hemisphere, Quaternary Science Reviews. vol. 5, 1986, pp. 1–514
^Wighart von Koenigswald: Lebendige Eiszeit. Theiss-Verlag, Stuttgart 2002, p. 34, ISBN3-8062-1734-3
^Ehlers, J., and Gibbard, P. L.: Quaternary Glaciations: Extent and Chronology 2: Part II North America. Elsevier, Amsterdam, 2004 ISBN0-444-51462-7
Sourcesedit
Roland Walter: Geologie von Mitteleuropa. Schweizerbartsche Verlagsbuchhandlung, Stuttgart, 1992, ISBN3-510-65149-9
René Hantke: Eiszeitalter. Band 2: Letzte Warmzeiten, Würm-Eiszeit, Eisabbau und Nacheiszeit der Alpen-Nordseite vom Rhein- zum Rhone-System. Ott, Thun, 1980, ISBN3-7225-6259-7
Hans Graul, Ingo Schäfer: Zur Gliederung der Würmeiszeit im Illergebiet. Straub, Munich, 1953. (Geologica Bavarica, 18).
Wolfgang Frey, Rainer Lösch: Lehrbuch der Geobotanik, Pflanze und Vegetation in Raum und Zeit. Elsevier Spektrum Akademischer Verlag, ISBN3-8274-1193-9
Dirk van Husen: Die Ostalpen in den Eiszeiten, Aus der Geologischen Geschichte Österreichs, Geologische Bundesanstalt Wien, ISBN3-900312-58-3
Rolf K. Meyer, Hermann Schmidt-Kaler: Auf den Spuren der Eiszeit südlich von München – östlicher Teil, Wanderungen in die Erdgeschichte, Vol. 8, ISBN978-3-931516-09-3
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This article needs to be updated Please help update this article to reflect recent events or newly available information Last update 2008 chart and 1972 dating when it should be 2013 iugs chart and 2012 walker paper see Holocene talk page May 2016 The Wurm glaciation or Wurm stage German Wurm Kaltzeit or Wurm Glazial colloquially often also Wurmeiszeit or Wurmzeit cf ice age usually referred to in the literature as the Wurm 1 often spelled Wurm was the last glacial period in the Alpine region It is the youngest of the major glaciations of the region that extended beyond the Alps themselves Like most of the other ice ages of the Pleistocene epoch it is named after a river in this case the Wurm in Bavaria a tributary of the Amper 2 Violet The extent of the Alpine ice sheet in the Wurm glaciation Blue The extent in earlier ice ages The Wurm ice age can be dated to about 115 000 to 11 700 years ago Sources differ about the dates depending on whether the long transition phases between the glacials and interglacials warmer periods are allocated to one or other of those periods The average annual temperatures during the Wurm ice age in the Alpine Foreland were below 3 C today 7 C That has been determined from changes in the vegetation pollen analysis as well as differences in the facies 3 Contents 1 Corresponding glaciations worldwide 2 Temporal classification 3 See also 4 References 5 Sources 6 External linksCorresponding glaciations worldwide edit nbsp The Wurm glaciation in the north the Weichselian in comparison with the Riss in the north the Saale The glacial advances were interrupted by warmer periods during which ancient European man the Neanderthals as successors of homo heidelbergensis spread out from the mountain zones and over the permafrost boundary to the north and northeast From about 40 000 BC modern Cro Magnon man settled these regions nbsp The Wurm glaciation shown in ice core data from the Antarctica and Greenland nbsp Moraines and gravel beds formed in the Wurm glaciation near Leutkirch Westallgau Germany Zeil castle can be seen on the left The corresponding ice age in North and Central Europe is known as the Weichselian glaciation after the German name for the Vistula river Despite the global changes in climate that were responsible for the major glaciations cycles the dating of the Alpine ice sheet advances does not correlate automatically with the farthest extent of the Scandinavian ice sheet 4 5 In North America the corresponding last ice age is called the Wisconsin glaciation 6 Temporal classification editFor the stratigraphic chronology see Weichselian glaciation In the Gelasian i e at the beginning of the Quaternary period around 2 6 million years ago an ice age began in the northern hemisphere which continues today Characteristic of such ice ages is the glaciation of the polar caps After the Gelasian followed the Early Middle and Late Pleistocene with a succession of several warm and cold periods The latter are often called ice ages or glacials the former term often being confused with the overarching ice age period The warm periods are called interglacials Glaciers repeatedly advanced from the Alps to the northern molasse foreland and left moraines and meltwater deposits behind that are up to several hundred metres thick Today the Pleistocene epoch in the Alps is divided into several phases the Biber Danube Gunz Haslach Mindel Riss and Wurm glaciations The greatest ice advance into the Alpine Foreland took place during the Riss glaciation cf the Saale glaciation in northern Europe The most recent foreland glaciation the Wurm did not have such an extensive and solid glacial front Nevertheless its terminal moraines which indicate the perimeter of the ice sheet extend as a single tongue well into the foreland Whilst they were hemmed in by the high mountainsides of the Alps once these rivers of ice entered the foreland they often combined to form huge glaciers The moraines and gravel beds formed in the Wurm glaciation are the best preserved because since then there have been no more similar geological processes Traces of the ice sheet have not been scoured out by later glaciers or overlaid by their sediments This allows a more precise dating for the Wurm glaciation than for earlier ice ages The Wurm glaciation was preceded by the Eemian which began about 126 000 years ago and lasted 11 000 years Then there was a significant slowdown characterized by occasional fluctuations of several degrees in average temperatures The various advances and retreats of glaciers associated with these temperature fluctuations are called stadials periods of relatively low temperatures and interstadials relatively higher temperatures The Wurm Glacial ended around 11 700 years ago with the beginning of the Holocene The cold period was followed by another warming which continues today and during which the glaciers are retreating However even in the Holocene there have been variations in temperature and ice advances the last one in the modern era being the so called Little Ice Age The Holocene is considered an interglacial of a larger ice age since the poles and the high mountain areas are still glaciated See also editGlacial series Glaciology Lake Toba Toba catastrophe theoryReferences edit Whittow John 1984 Dictionary of Physical Geography London Penguin 1984 p 586 ISBN 0 14 051094 X Rolf K Meyer Hermann Schmidt Kaler Auf den Spuren der Eiszeit sudlich von Munchen ostlicher Teil Wanderungen in die Erdgeschichte Vol 8 ISBN 978 3 931516 09 3 Rolf K Meyer Hermann Schmidt Kaler Auf den Spuren der Eiszeit sudlich von Munchen ostlicher Teil Wanderungen in die Erdgeschichte Vol 8 ISBN 978 3 931516 09 3 Sibrava V Bowen D Q and Richmond G M Quaternary Glaciations in the Northern Hemisphere Quaternary Science Reviews vol 5 1986 pp 1 514 Wighart von Koenigswald Lebendige Eiszeit Theiss Verlag Stuttgart 2002 p 34 ISBN 3 8062 1734 3 Ehlers J and Gibbard P L Quaternary Glaciations Extent and Chronology 2 Part II North America Elsevier Amsterdam 2004 ISBN 0 444 51462 7Sources editRoland Walter Geologie von Mitteleuropa Schweizerbartsche Verlagsbuchhandlung Stuttgart 1992 ISBN 3 510 65149 9 Rene Hantke Eiszeitalter Band 2 Letzte Warmzeiten Wurm Eiszeit Eisabbau und Nacheiszeit der Alpen Nordseite vom Rhein zum Rhone System Ott Thun 1980 ISBN 3 7225 6259 7 Hans Graul Ingo Schafer Zur Gliederung der Wurmeiszeit im Illergebiet Straub Munich 1953 Geologica Bavarica 18 Wolfgang Frey Rainer Losch Lehrbuch der Geobotanik Pflanze und Vegetation in Raum und Zeit Elsevier Spektrum Akademischer Verlag ISBN 3 8274 1193 9 Dirk van Husen Die Ostalpen in den Eiszeiten Aus der Geologischen Geschichte Osterreichs Geologische Bundesanstalt Wien ISBN 3 900312 58 3 Rolf K Meyer Hermann Schmidt Kaler Auf den Spuren der Eiszeit sudlich von Munchen ostlicher Teil Wanderungen in die Erdgeschichte Vol 8 ISBN 978 3 931516 09 3External links editKarte Umwelt Biologie und Geologie lastiszeitliches 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