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