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. See also Glacial series Glaciology Lake Toba Toba catastrophe theory References Sources Roland Walter: Geologie von Mitteleuropa. Schweizerbartsche Verlagsbuchhandlung, Stuttgart, 1992, René Hantke: Eiszeitalter. Band 2: Letzte Warmzeiten, Würm-Eiszeit, Eisabbau und Nacheiszeit der Alpen-Nordseite vom Rhein- zum Rhone-System. Ott, Thun, 1980, 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, Dirk van Husen: Die Ostalpen in den Eiszeiten, Aus der Geologischen Geschichte Österreichs, Geologische Bundesanstalt Wien, Rolf K. Meyer, Hermann Schmidt-Kaler: Auf den Spuren der Eiszeit südlich von München – östlicher Teil, Wanderungen in die Erdgeschichte, Vol. 8, External links Karte: Pleistocene events Ice ages Holocene events Geology of the Alps Last Glacial Period