TY  - JOUR
A1  - Scherler, Dirk
A1  - Bookhagen, Bodo
A1  - Wulf, Hendrik
A1  - Preusser, Frank
A1  - Strecker, Manfred
T1  - Increased late Pleistocene erosion rates during fluvial aggradation in the Garhwal Himalaya, northern India
JF  - Earth & planetary science letters
N2  - The response of surface processes to climatic forcing is fundamental for understanding the impacts of climate change on landscape evolution. In the Himalaya, most large rivers feature prominent fill terraces that record an imbalance between sediment supply and transport capacity, presumably due to past fluctuations in monsoon precipitation and/or effects of glaciation at high elevation. Here, we present volume estimates, chronological constraints, and Be-10-derived paleo-erosion rates from a prominent valley fill in the Yamuna catchment, Garhwal Himalaya, to elucidate the coupled response of rivers and hillslopes to Pleistocene climate change. Although precise age control is complicated due to methodological problems, the new data support formation of the valley fill during the late Pleistocene and its incision during the Holocene. We interpret this timing to indicate that changes in discharge and river-transport capacity were major controls. Compared to the present day, late Pleistocene hillslope erosion rates were higher by a factor of similar to 2-4, but appear to have decreased during valley aggradation. The higher late Pleistocene erosion rates are largely unrelated to glacial erosion and could be explained by enhanced sediment production on steep hillslopes due to increased periglacial activity that declined as temperatures increased. Alternatively, erosion rates that decrease during valley aggradation are also consistent with reduced landsliding from threshold hillslopes as a result of rising base levels. In that case, the similarity of paleo-erosion rates near the end of the aggradation period with modern erosion rates might imply that channels and hillslopes are not yet fully coupled everywhere and that present-day hillslope erosion rates may underrepresent long-term incision rates. (C) 2015 Elsevier B.V. All rights reserved.
KW  - paleo-erosion rates
KW  - climate change
KW  - river terraces
KW  - landscape evolution
KW  - hillslopes
KW  - Himalaya
Y1  - 2015
U6  - https://doi.org/10.1016/j.epsl.2015.06.034
SN  - 0012-821X
SN  - 1385-013X
VL  - 428
SP  - 255
EP  - 266
PB  - Elsevier
CY  - Amsterdam
ER  -