Giétrogletscher
| Giétrogletscher | ||
|---|---|---|
 Glacier tongue in July 2006 |
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| location | Canton of Valais , Switzerland | |
| Mountains | Valais Alps | |
| Type | Mountain glacier | |
| length | 4.2 km (2011) | |
| surface | 5.549 km² (2003) | |
| Exposure | Nutrient area northwest, consumption area west | |
| Altitude range | 3830 m above sea level M. - 2597 m above sea level M. (2005) | |
| Tilt | ⌀ 16 ° (29%) | |
| Ice volume | 0.49 ± 0.08 km³ (2003) | |
| Coordinates | 596316 / 93192 | |
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| drainage | Cascade du Giétro, Lac de Mauvoisin , Dranse de Bagnes , Dranse , Rhone | |
The Giétrogletscher (French Glacier du Giétro , sometimes written Giétroz ) is located in the southwestern Valais Alps in Switzerland . It is about 4.2 km long, 1.5 km wide in the upper part and covers an area of about 5.5 km².
location
The Giétrogletscher has its origins on the northern slope of the rocky ridge between the Ruinette ( 3875 m above sea level ) and the Mont Blanc de Cheilon ( 3870 m above sea level ). In its upper part the glacier has only a slight slope. It initially flows north, flanked by Mont Rouge du Giétroz in the west, but gradually turns west at the foot of the Pleureur ( 3704 m above sea level ). On the last kilometer, the Giétrogletscher drops steeply with a gradient of 40% and is very rugged. The glacier tongue is currently at an altitude of around 2600 m . A small part of the glacier flows over the Col de Cheilon ( 3243 m above sea level ) to the Cheilon glacier in the rear Val d'Hérémence .
The water of the Giétrogletscher flows into the Lac de Mauvoisin reservoir and from there with the Dranse de Bagnes through the Val de Bagnes to the Rhone .
Ice falls
During the Little Ice Age , the Giétrogletscher reached further down the steep slope in the area of today's glacier tongue and, above all, had a significantly larger volume in this area. Therefore, from the 16th to the 19th century, there were repeated spectacular ice falls (called Canonnades du Giétroz ), which filled up the valley floor of the Dranse de Bagnes in the area of the current dam of the Lac de Mauvoisin . A lake built up behind this ice wall . The outbreaks of the lake often caused flood damage throughout the Val de Bagnes.
The most catastrophic tidal wave occurred in 1595 and claimed 140 lives. After an ice fall in 1818, a tunnel was driven through the ice dam under the direction of Ignaz Venetz , which was supposed to divert the dammed water. After one third of the lake was emptied, the ice dam broke and the subsequent tidal wave again killed 44 people (34 of them in the city of Martigny ). Due to the melting of the dangerous lower part of the glacier tongue, the dangerous situation has eased significantly in the 20th century. Since the Lac de Mauvoisin was dammed, any ice falls into the lake have occurred. The situation at the glacier tongue is monitored with measurements. If a major demolition is imminent, part of the lake could be drained so that the ice fall would not lead to the lake spilling over the dam wall.
See also
Web links
- Giétrogletscher on the ETHorama platform
- Map section at map.geo.admin.ch
Individual evidence
- ↑ a b Research Institute for Hydraulic Engineering, Hydrology and Glaciology (VAW) of the ETH Zurich (Ed.): Giétroglasetscher. In: Swiss Glacier Measurement Network. ( ethz.ch , also as PDF , accessed on January 10, 2014).
- ↑ a b c WGMS: Fluctuations of Glaciers Database. World Glacier Monitoring Service, Zurich 2013 ( DOI: 10.5904 / wgms-fog-2013-11 ), accessed on December 11, 2013
- ^ Research institute for hydraulic engineering, hydrology and glaciology (VAW) of the ETH Zurich : Giétroglasetscher. In: Glacier Natural Hazards. ( ethz.ch ( page no longer available ), also as a PDF ( page no longer available )).
- ↑ Daniel Farinotti, Matthias Huss, Andreas Bauder, Martin Funk: An estimate of the glacier ice volume in the Swiss Alps. In: Global and Planetary Change. 68: 225-231, 2009 ( online ; PDF; 756 kB).