HR: 09:15h
AN: H41A-06    [PDF]
TI: Late Quaternary Intensified Monsoon Phases Control Landscape Evolution in the NW Himalaya
AU: * Bookhagen, B
EM: bodo@geo.uni-potsdam.de
AF: Univ Potsdam, Institut fuer Geowissenschaften Postfach 60 15 53, Potsdam, 14415 Germany
AU: Thiede, R C
EM: thiede@geo.uni-potsdam.de
AF: Univ Potsdam, Institut fuer Geowissenschaften Postfach 60 15 53, Potsdam, 14415 Germany
AU: Strecker, M R
EM: strecker@geo.uni-potsdam.de
AF: Univ Potsdam, Institut fuer Geowissenschaften Postfach 60 15 53, Potsdam, 14415 Germany
AB: The intensity of the Asian summer monsoon circulation varies over decadal to millennial timescales, reflected in changes in terrestrial depositional environments and marine sediment records. However, the influence and mechanisms of short-lived intensified monsoon phases on landscape evolution, their effect on sedimentation rates, and the related change in precipitation distribution are not well understood. Here, we use high-resolution satellite-derived precipitation data from NW India of the last decade and compare its distribution to the strengthened monsoon of 2002 as an analog for past, longer lasting monsoon intensifications. The 2002 event dramatically increased precipitation in the high-elevation, arid areas of the western and northwestern parts of the orogen and caused increased mass wasting and flooding. Similarly, during longer lasting late Pleistocene (27 ka) and mid-Holocene (6 ka) intensified monsoon phases that lag 3 ka behind maximum insolation, exceptionally large landslides were generated in these climatically sensitive regions and serve as proxies for increased precipitation and runoff. These episodes of high climatic variability were also coupled with a six-fold increase in sedimentation rates emphasizing the pronounced imprint of short lived climate change on surface processes and landscape evolution.
DE: 1815 Erosion and sedimentation
DE: 1824 Geomorphology (1625)
DE: 1860 Runoff and streamflow
SC: Hydrology [H]
MN: 2003 Fall Meeting