The historical Saklei Shuyinj and Chateboi Glacier Dams as triggers for lake outburst cascades in the Karambar valley, Hindukush

Since the mid-nineteenth century, devastating glacier lake outbursts have occurred in the Karambar Valley. The exact source areas of these floods are to date unknown. The present study uses geomorphologic field evidence and interviews of local inhabitants to reconstruct nine potential glacier dams in the Karambar Valley within a horizontal distance of only 40 km. The article focuses on the geomorphologic reconstruction of the highest glacier dams, the Chateboi and Saklei Shuyinj Glaciers. Their lake basins were connected in former times resulting in a complex interfingering of lake sediments, lake terraces and glacial deposits. The outbursts of these lakes could have triggered the drainage of one of the lower ice-dammed lakes (Sokther Rabot, Chillinji, Warghut or Karambar) and therefore initiated an outburst cascade in the upper Karambar Valley. Successive glacier dams are wide spread in the Karakoram, and cascading lakes might have also played a role in other lake outburst scenarios. In the Karambar Valley, even today the Chateboi Glacier blocks the Karambar River over a distance of 4 km and represents a permanent hazard for the villages located downstream.