An alpentor (literally "Alpine gateway", plural alpentore) in geology is the point where an entire glacier forced its way through to the Alpine Foreland from the Alps during the ice age.
During the Würm glaciation, where several glaciers from different Alpine valleys met or flowed through narrow passages at the edge of the Alps, ice was piled up. Such bottlenecks had a significant impact on the level of the ice sheet which meant that it eventually flowed over low mountain passes and ridges and the glaciers were combined into a network of ice streams.
Alpentore, through which particularly large masses of ice poured into the surrounding plains, were mainly located at the mouths of large longitudinal valleys such as Inn, Rhine or Salzach valleys. These glaciers penetrated up to 50 kilometres (31 mi) into the lowlands. Even valleys that appear rather insignificant today such as those of the Isar, Loisach and Ammer rivers, were able to produce large tongues of ice when their glaciers were fed by larger ones, such as the Inn Valley Glacier (e.g. via the Fern Pass). By contrast with such large glaciers, quite isolated valleys, such as those of the Iller or the Lech, could only produce much smaller glacial tongues.
A further prerequisite for glaciers extending into the Alpine foreland are high mountains. East of the Salzach, glacier tongues hardly reached the edge of the Alps, because the mountains of the Low Tauern, unlike those of the High Tauern did not produce enough ice. So the alpentore were found mainly in the Bavarian Alpine Foreland. One of the few examples at the southern edge of the Alps was the comparatively small alpentor of today's Tagliamento valley. [1]
In the Inn Valley (towards Rosenheim) the Inn Glacier was forced between the Wildbarren and the Kranzhorn at a height of about 1,300 m above sea level (NN) . A tributary, the Isar valley glacier flowed south from Bad Tölz between the Blomberg and the Rechelkopf at a height of about 1,000 m (3,300 ft) into the plains.
At the Walchensee and Kochelsee lakes a tributary of the Inn Glacier pushed through over the Kesselberg at a height of 1,400 m (4,600 ft) between the Jochberg and the Herzogstand.
The Loisach Glacier, another tributary, flowed between the Wank and the Kramerspitz near Garmisch at a height of about 1,700 m (5,600 ft). In present-day Murnau the ice stream reached a height of 1,200 m (3,900 ft). [2]
The Salzach is a river in Austria and Germany. It is 227 kilometres (141 mi) in length and is a right tributary of the Inn, which eventually joins the Danube. Its drainage basin of 6,829 km2 (2,637 sq mi) comprises large parts of the Northern Limestone and Central Eastern Alps. 83% of its drainage basin lies in Austria, the remainder in Germany (Bavaria). Its largest tributaries are Lammer, Berchtesgadener Ache, Saalach, Sur and Götzinger Achen.
The Isar is a river in Austria, and Bavaria. Its source is in the Karwendel mountain range of the Alps. The Isar river enters Germany near Mittenwald and flows through Bad Tölz, Munich, and Landshut before reaching the Danube near Deggendorf. With 295 km length, it is among the longest rivers in Bavaria. It is Germany's second most important tributary of the Danube.
The Bavarian Alps is a collective name for several mountain ranges of the Northern Limestone Alps within the German state of Bavaria.
The Kitzbühel Alps are a mountain range of the Central Eastern Alps surrounding the town of Kitzbühel in Tyrol, Austria. Geologically they are part of the western slate zone.
The Würm glaciation or Würm stage, usually referred to in the literature as the Würm, 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.
The Central Eastern Alps, also referred to as Austrian Central Alps or just Central Alps, comprise the main chain of the Eastern Alps in Austria and the adjacent regions of Switzerland, Liechtenstein, Italy and Slovenia. South them is the Southern Limestone Alps.
The Amper, called the Ammer upstream of the Ammersee, through which it runs, is the largest tributary of the Isar in southern Bavaria, Germany. It flows generally north-eastward, reaching the Isar in Moosburg, about 185 kilometres (115 mi) from its source in the Ammergau Alps, with a flow of 45 m³/s. Including its tributary, Linder, it is 209.5 km (130.2 mi) long. Major tributaries are the Glonn, which rises near Augsburg; the Würm, which is the outflow of Lake Starnberg; and the Maisach.
The Riss glaciation, Riss Glaciation, Riss ice age, Riss Ice Age, Riss glacial or Riss Glacial is the second youngest glaciation of the Pleistocene epoch in the traditional, quadripartite glacial classification of the Alps. The literature variously dates it to between about 300,000 to 130,000 years ago and 347,000 to 128,000 years ago. It coincides with the Saale glaciation of North Germany. The name goes back to Albrecht Penck and Eduard Brückner who named this cold period after the river Riss in Upper Swabia in their three-volume work Die Alpen im Eiszeitalter published between 1901 and 1909.
Eastern Alps is the name given to the eastern half of the Alps, usually defined as the area east of a line from Lake Constance and the Alpine Rhine valley, up to the Splügen Pass at the Alpine divide, and down the Liro River to Lake Como in the south. The peaks and mountain passes are lower than the Western Alps, while the range itself is broader and less arched.
The Radstadt Tauern are a subrange of the Central Eastern Alps in Austria. Together with the Schladming Tauern, the Rottenmann and Wölz Tauern and the Seckau Tauern the Radstadt Tauern form the major range of mountains known as the Low Tauern. The mountains are found in the southeast of the Austrian state of Salzburg, between the upper reaches of the Enns and Mur rivers.
Side valleys and tributary valleys are valleys whose brooks or rivers flow into greater ones.
The Bavarian Prealps are a mountain range within the Northern Limestone Alps in south Germany. They include the Bavarian Prealp region between the river Loisach to the west and the river Inn to the east; the range is about 80 kilometres (50 mi) long and 20–30 kilometres (12–19 mi) wide. The term is not defined politically, but alpine-geographically because small areas of the Bavarian Prealps lie in Tyrol.
The Ammergau Alps are a mountain range in the Northern Limestone Alps in the states of Bavaria (Germany) and Tyrol (Austria). They cover an area of about 30 x 30 km and begin at the outer edge of the Alps. The highest summit is the Daniel which has a height of 2,340 metres (7,680 ft).
The Venediger Group is a mountain range of the Central Eastern Alps. Together with the Granatspitze Group, the Glockner Group, the Goldberg Group, and the Ankogel Group, it forms the main ridge of the High Tauern. The highest peak is the Großvenediger at 3,657 m (AA), which gives its name to the group. Considerable parts of the Venediger Group belong to the core zone of the High Tauern National Park.
The Mangfall Mountains, or sometimes Mangfall Alps, are the easternmost part of the Bavarian Prealps that, in turn, belong to the Northern Limestone Alps. The name comes from the river Mangfall, whose tributaries, the Rottach, Weißach, Schlierach and Leitzach, drain large parts of the area and form an important drinking water reservoir for the city of Munich.
The Mieming(er) Range, Mieminger Chain or Mieminger Mountains, is a mountain range of the Northern Limestone Alps in the Eastern Alps. It is located entirely in Austria within the state of Tyrol. This sub-group is somewhat in the shadows of its more famous neighbour, the Wetterstein to the north. Whilst the region around the Coburger Hut and the lakes of Seebensee and Drachensee in the west and the Hohe Munde in the extreme east receive large numbers of visitors, the less developed central area remains very quiet. The Hohe Munde is also a popular and challenging ski touring destination.
The Pinzgau Ridgeway is a roughly 25 kilometre long ridgeway in the Kitzbühel Alps in the Austrian federal state of Salzburg.
The glacial series refers to a particular sequence of landforms in Central Europe that were formed during the Pleistocene glaciation beneath the ice sheets, along their margins and on their forelands during each glacial advance.
The geology of Austria consists of Precambrian rocks and minerals together with younger marine sedimentary rocks uplifted by the Alpine orogeny.
The Schlatenkees is a glacier in the Venediger Group that is in the core zone of the High Tauern National Park, east of the Großvenediger. It is in the East Tyrolean community of Matrei in Osttirol. With an area of around 9 square kilometres (3.5 sq mi), the Schlatenkees is the largest valley glacier in East Tyrol and, after the Obersulzbachkees, the second largest glacier in the Venediger group. The exposure is mainly to the east, in the highest area also to the south-east.