T22 Determining the Extent of Glaciation in Areas of Limited Evidence (Posters)

Friday, 25 July 2003
1:30 PM - 4:30 PM

CHANGES OF LANDSCAPE AFTER DEGLACIATION IN THE BATURA- AND THE HARAMOSH MUZTAGH, N.W. KARAKORAM

Paper number: T22-2
Program: Technical Sessions
Time: 1:30 PM – 4:30 PM

Authors

Abstract

The glaciation history of the Haramosh Valley and Bar Valley gives basic information about the landscape after deglaciation. The former glacial extend can be found using the system of glaciogeomorphic indicators and the snowline calculation. During postglacial period the tributary glaciers Kukuar- Baltar and Daintar in the Batura Muztagh and the Mani- Baska and Phuparash branches in the Rakaposhi/ Haramosh reached few kilometers downvalley and left the Great Lateral Moraine (GLM) type. The ice thickness of the postglacial tongue was even 300 m or more. Today the glacier surfaces have been sunk in deeply without retreating their ends of the subrecent stage. This is typical for glaciers in the subtropics with high average catchment areas of c. 6500 m and a dense surface moraine cover. During the Late Glacial c. 700 – 800 m thick glaciers reached downvalley into the main the Indus and the Hunza river. After the Late Glacial and Postglacial period loose morainic sediments are widespread along the oversteep and polished trough profils.

As a new aspect, investigation has been done to find out the rate of postglacial erosion of the solid rock and loose morainic material after deglaciation. In a first step recent erosional processes and forms have to be selected from the movements originated exclusively through destabilization of the slopes after the ice retreat. In a second step the volume of break offs in the solid rock and morainic material should be deduced. For this quantitative analysis we use a photogrammetric method which allows to extend a digital field model without having a fixed position of the camera used in the field. Because the postglacial stage is clearly separated from the Late Glacial extend choosen valleys are qualified for this subject. The space for geomorphological processes after deglaciation in between these periods has a vertical distance of 1200 m and a horizontal distance of 18 – 26 km.