Unterer Grindelwaldgletscher

Landslide and formation of glacial lakes, October 2006

In the summer of 2006 a rock mass with a volume of several 100'000 cubic meters detatched itself from a rock face on the orographic lefthand side of the glacier tongue. Piece by piece smaller and larger amounts of limestone crashed down on to the glacier. This process clearly had been triggered by the massive recession of the glacier as it no longer supported the rock along its margin. Many spectators came to observe rockfalls from the opposite and safe side of the valley. The town of Grindelwald was in no immediate danger, but by autumn 2006 two small glacial lakes had formed which potentially could cause flooding downvalley.

Unterer Grindelwaldgletscher, landslide
The early morning sun highlights the landslide (centre). Photo taken from location 647.100, 161.960, 1468m.
Unterer Grindelwaldgletscher, landslide
Telephoto view from the same location as the previous image. Note the vertical cracks in the rock.
Unterer Grindelwaldgletscher, landslide
Small rockfall (few cubic metres) generating a dust cloud.
Unterer Grindelwaldgletscher, landslide
Vertical panorama: Landslide left of centre; lower right deposit of an ice avalanche from Challifirn (invisible, behind col at the top).
Unterer Grindelwaldgletscher, landslide
Lake dammed by the landslide deposit.
Unterer Grindelwaldgletscher, landslide
Landslide debris in the lake. This and previous photo taken from the now abandoned path to Stieregg, at 647.440, 161.140, 1650m.
Unterer Grindelwaldgletscher, landslide
Landslide and dammed lake from Stieregg. Lateral moraine with prominent erosional rills on the left.
Unterer Grindelwaldgletscher, landslide
Bluish landslide debris (limestone); brownish moraine (lower left, crystalline rocks of the Aaremassiv).
Unterer Grindelwaldgletscher, glacial lake
Tongue of Unterer Grindelwaldgletscher and newly formed glacial lake. Crevasses around the lake indicate lowering of the ice surface.
Unterer Grindelwaldgletscher, glacial lake
The last days in the life of some grasses. Growing on the edge of a lateral moraine, they will soon fall down as erosion continues.
Unterer Grindelwaldgletscher, glacial lake
Telephoto view of the glacial lake. Below: stranded ice blocks. These were deposited by waves generated during calving events.
Unterer Grindelwaldgletscher, glacial lake
Enlargement from previous picture: Note foliation (layers in the ice) between crevasses.
Unterer Grindelwaldgletscher, ice avalanche
Thundering ice avalache descending over "Heissi Blatta".
Unterer Grindelwaldgletscher, hut
Shepherd's hut above the glacier tongue. The rock outcrop serves as snow-avalanche protection.
Unterer Grindelwaldgletscher, lateral moraine
Fluted left lateral moraine.
Unterer Grindelwaldgletscher, panorama
Glacier tongue, lake and landslide (left to righ; panoramic photo: the wide image may require scrolling to the right).
Unterer Grindelwaldgletscher, panorama
As previous image, but taken from slightly higher up. Taken from 647.820, 161.200, 1770m (panoramic photo: the wide image may require scrolling to the right).
   
Photos Jürg Alean