Aletsch Glacier - Geography

Geography

The Aletsch Glacier is one of the many glaciers located between the cantons of Berne and Valais on the Bernese Alps located east of the Gemmi Pass. The whole area is considered to be the largest glaciated area in western Eurasia. The Fiescher and Aar glaciers lying on the east have similar extensions.

Except the Finsteraarhorn, all the highest summits of the Bernese Alps are located within the drainage basin of the glacier. The Jungfrau and Mönch constitute the northern boundary; the Gross Fiescherhorn and Gross Wannenhorn lie on its east side; finally the culminating point, the Aletschhorn (4,195 meters/13,763 feet) is located on the west side.

Before reaching the maximum flow, three smaller glaciers converge at Concordia (German: Konkordiaplatz):

• From the western mouth flows the Great Aletschfirn, which runs along the northern foot of the Aletschhorn and Dreieckhorn. The Aletschfirn is supplied from the north by three notable firns: the Ebnefluhfirn, the Gletscherhornfirn, and the Kranzberfirn. All of these Firns have their starting points at around 3800 m. From the Ebnefluhfirns to the Konkordiaplatz, the Aletschfirn is 9 km long and is on average about 1.5 km wide. From the west, the Aletschfirn flows over the 3173 m high glacier pass, the Lötschenlücke, connecting with the Langgletscher, and then into the Lötschental valley.

• From the northwestern mouth flows the Jungfraufirn. This firn in fact represents the straight continuation of the Aletsch Glacier, yet is the shortest of the three tributary glaciers. It has its origin on the southern flank of the Mönch, at the Jungfraujoch and at the eastern flank of the Jungfrau. Up to the Konkordiaplatz, the Jungfraufirn is a scarce 7 km long, and returns to flank the Kranzberg in the west and the Trugberg in the east. At its highest point, it is 2 km wide, and further down it is still a good 1 km wide.

• From the northern mouth flows the Ewigschneefeld (Eternal snow field), where its starting point takes the east flank of the Mönchs. In an elbow, it flanks from Trugberg in the west and the Fiescherhorn and Grünhorn in the east, flowing on to the Konkordiaplatz. Up to here, it is about 8 km long and averages about 1.2 km wide. The mouth at the Konkordplatz it follows over a rise with a descent from 25 to 30 percent; here, the glacier is sharply split. Against the north is the Ewigschneefeld over the snow-covered pass of the Lower Mönchsjochs (3529 m high), connected with the catchment area of the Lower Grindelwald Glacier. Through the Higher Mönchsjoch (3627 m high) between the Mönch and the Trugberg stands a connection to the Jungfraufirn.

Below Concordia the glacier runs towards the valley of the Upper Rhône; on the left (east) side, near Bettmeralp, lies a glacier lake, Lake Märjelen (German: Märjelensee) (2,350 meters/7,711 feet); on the right side lie the glaciers of Mittelaletsch and Oberaletsch. At the end of the glacier, below the villages of Belalp (west) and Riederalp (east), begin the Massa river. The river flows through gorges and through the Lake Gibidum before reaching the Rhone near Brig.