Browsing by Author "Verma, Akshaya"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Characteristics of surge-type tributary glaciers, Karakoram
    (Elsevier B.V., 2022-02-10T00:00:00) Bhambri, Rakesh; Hewitt, Kenneth; Haritashya, Umesh K.; Chand, Pritam; Kumar, Amit; Verma, Akshaya; Tiwari, Sameer Kumar; Rai, Santosh Kumar
    The Karakoram has a large concentration of surge-type glaciers, including 69 tributary glaciers, compared to 152 surge-type main or trunk glaciers. The paper addresses the interactions between tributary and trunk glaciers using digital elevation models (DEMs), surface displacement, field and archival reports. In particular, it explores the behavior and impacts of 13 tributary glacier surges on three trunk glaciers, namely the Hispar, Braldu and Panmah. Observations include five surge tributaries of Panmah, five of Braldu, and three of Hispar. We observed ASTER DEMs can help in some cases to detect surge signature where automated surface displacement does not detect the surge. We also observed substantial differences in surge dimensions, timing and histories of the main trunk glacier and their tributaries. East Braldu III tributary surged between 2000 and 2003, whereas East Braldu IV surged from 2003 to 2006, but in these periods, no other tributary shows surge signature. Between 2013 and 2016, Braldu trunk Glacier surged along with four tributaries out of five except West Braldu I. Volumes and geometry of ice transferred from tributary to trunk glaciers are unique to each case, but the surging ice melted rapidly in about 2 to 4 years for some cases such as Little Skamri and Drenmang. The tributary ice modified all studied trunk glacier dynamics, morphology, distribution of debris and hypsography. The ice transferred from tributaries such as Little Skamri and Drenmang blocked the flow of trunk Nobande Sobonde Glacier from 2004 to 2006. Such ice transfer by surge tributaries to the main trunk glacier is referred here as surge-modified ice. It introduces indirect and post-surge effects and complicates or delay in tracking glacier responses to climate change. Also, mass balance in surge-type and surge-modified glaciers differ from systematic direct responses to climate in non-surge-type glaciers. Therefore, more research and monitoring are required to address the distinct responses of such glaciers and individual tributaries to better understand the heterogeneity of surging glaciers in Karakoram. � 2022 Elsevier B.V.
  • No Thumbnail Available
    Item
    Reassessing the Karakoram Through Historical Archives
    (Springer International Publishing, 2022-11-11T00:00:00) Bhambri, Rakesh; Chand, Pritam; N�sser, Marcus; Kawishwar, Prashant; Kumar, Amit; Gupta, Anil K.; Verma, Akshaya; Tiwari, Sameer K.
    The Karakoram region is an integral part of the Hindu Kush�Karakoram�Himalaya (HKH) mountain system and forms the great divide between the drainage of the Indus and Tarim basins. This region has a substantial geographical, historical, economical, cultural, and geopolitical importance owing to its location, rugged topography, distinct climate regime, and the presence of numerous glaciers. It acts as a water tower where its unique assemblage paved the way for developing ancient trade routes facilitating cultural exchange between Central Asia and the Indian subcontinent. It has attracted a large number of expeditions and scientific studies for more than 200 years, bringing significant advances in geographical knowledge. However, the spatial extent of the Karakoram in many studies particularly during the 2010s exhibits a large inconsistency. We, therefore, complied ?100 maps and vast literature to present the evolution of the geographical term �the Karakoram� and its spatial extent based on historical archives. We also provide a digital outline of the Karakoram region using GIS tools based on descriptive enumerations of the Royal Geographical Society (RGS) and the Survey of India (SoI) which we hope will provide new insight for a wide range of scientific disciplines, including geography, glaciology, geology, history, and cartography. � The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.