Late Holocene glacier change in the eastern Nyainqêntanglha Range, SE Tibet Von der Fakultät für Georessourcen und Materialtechnik der Rheinisch‐Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von M.A. David Loibl aus Aachen Berichter: Univ.‐Prof. Dr. rer. nat. Frank Lehmkuhl Univ.‐Prof. Dr. rer. nat. Achim Bräuning Tag der mündlichen Prüfung: 06. Juli 2015 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar. Table of contents List of figures .................................................................................................................................... i List of tables .................................................................................................................................... ii List of abbreviations ....................................................................................................................... iii 1 Introduction ................................................................................................................................. 1 1.1 Motivation ..................................................................................................................................... 1 1.2 Objectives and approach ............................................................................................................... 2 1.3 Thesis outline................................................................................................................................. 3 2 Current state of research .............................................................................................................. 5 2.1 Atmospheric circulation patterns .................................................................................................. 5 2.2 Paleoclimate and glacier fluctuations ........................................................................................... 7 2.2.1 Paleoclimate reconstruction ................................................................................................................. 7 2.2.2 Holocene paleoclimate on the Tibetan Plateau .................................................................................. 10 2.2.3 Glaciers and climate change ................................................................................................................ 13 2.2.4 Late Holocene glacier fluctuations and climatic forcing ...................................................................... 14 2.2.5 Human perspective: risks and challenges ........................................................................................... 15 2.3 Methodological background ....................................................................................................... 15 2.3.1 Remote sensing of glaciers .................................................................................................................. 15 2.3.2 Equilibrium line altitude calculation .................................................................................................... 17 2.3.3 Dating of Holocene glacier deposits .................................................................................................... 19 3 Regional setting .......................................................................................................................... 22 3.1 Geology ........................................................................................................................................ 22 3.2 Climate ......................................................................................................................................... 23 3.3 Geomorphology ........................................................................................................................... 25 3.4 Glaciers ........................................................................................................................................ 26 3.5 Vegetation ................................................................................................................................... 27 4 Reconstructing glacier retreat since the Little Ice Age in SE Tibet by glacier mapping and equilibrium line altitude calculation .............................................................................................. 28 4.1 Introduction ................................................................................................................................. 28 4.2 Regional setting and glacier distribution ..................................................................................... 30 4.3 Methods and materials ............................................................................................................... 33 4.3.1 Data selection ...................................................................................................................................... 33 4.3.2 Glacier mapping .................................................................................................................................. 35 4.3.3 Glacier classification ............................................................................................................................ 36 4.3.4 Calculation of ELA estimates ............................................................................................................... 38 4.3.5 Fieldwork ............................................................................................................................................. 39 4.4 Results ......................................................................................................................................... 40 4.4.1 Glacier case studies ............................................................................................................................. 40 4.4.2 Glacier types and spatial distribution .................................................................................................. 41 4.4.3 Length change analysis ........................................................................................................................ 44 4.4.4 ELA calculations ................................................................................................................................... 46 4.5 Discussion .................................................................................................................................... 50 4.5.1 Quality assessment .............................................................................................................................. 50 4.5.2 Influences of topography and climate ................................................................................................. 51 4.5.3 Glacier change ..................................................................................................................................... 52 4.5.4 Monsoon and glaciers ......................................................................................................................... 53 4.6 Conclusions .................................................................................................................................. 55 5 Glaciers and equilibrium line altitudes of the eastern Nyainqêntanglha Range, SE Tibet ............. 58 5.1 Introduction ................................................................................................................................. 58 5.2 Study area .................................................................................................................................... 59 5.3 Methods ...................................................................................................................................... 62 5.3.1 Data and glacier mapping .................................................................................................................... 62 5.3.2 Glacier classification ............................................................................................................................ 64 5.3.3 ELA calculation .................................................................................................................................... 64 5.3.4 Post‐processing ................................................................................................................................... 66 5.4 Map Design .................................................................................................................................. 66 5.5 Interpretation .............................................................................................................................. 67 5.6 Conclusions .................................................................................................................................. 69 5.7 Software ...................................................................................................................................... 69 6 Toward a late Holocene glacial chronology for the eastern Nyainqêntanglha Range, southeastern Tibet ............................................................................................................................................. 70 6.1 Introduction ................................................................................................................................. 70 6.2 Regional setting ..........................................................................................................................