@article{TrauthBookhagenMuelleretal.2003,
  author    = {Trauth, Martin H. and Bookhagen, Bodo and Mueller, Andreas and Strecker, Manfred},
  title     = {Erosion and climate change in the Santa Maria Basin, NW Argentina during the last 40,000 yrs},
  year      = {2003},
  abstract  = {Present erosion and sediment flux in the semi-arid intramontane Santa Maria Basin, NW Argentina are compared with conditions during a period of wetter and more variable climate at about 30,000 14C yrs ago. The results suggest that the influence of climate change on the overall erosional sediment budget is significant, mainly because of a change in the erosion regime coupled with an increase in mass movements. The most effective mechanism to increase landslide activity in this environment is a highly variable climate on inter-annual timescales. In contrast, Quaternary changes in erosional budgets due to variations in moisture regimes is small in the Santa Maria Basin. Since the magnitude of a potential increase in background erosion as well as enhanced landsliding is smaller than typical levels of uncertainty of erosional budgets for such large basins, it is not likely that climate-driven erosional unloading can influence tectonic style and rates in this semi-arid environment on time scales of several 103 to 104 years.},
  language  = {en}
}
@article{ThiedeBookhagenArrowsmithetal.2004,
  author    = {Thiede, Rasmus Christoph and Bookhagen, Bodo and Arrowsmith, J. Ram{\´o}n and Sobel, Edward and Strecker, Manfred},
  title     = {Climatic control on rapid exhumation along the Southern Himalayan Front},
  issn      = {0012-821X},
  year      = {2004},
  abstract  = {Along the Southern Himalayan Front (SHF), areas with concentrated precipitation coincide with rapid exhumation, as indicated by young mineral cooling ages. Twenty new, young ( < 1-5 Ma) apatite fission track (AFT) ages have been obtained from the Himalayan Crystalline Core along the Sutlej Valley, NW India. The AFT ages correlate with elevation, but show no spatial relationship to tectonic structures, such as the Main Central Thrust or the Southern Tibetan Fault System. Monsoonal precipitation in this region exerts a strong influence on erosional surface processes. Fluvial erosional unloading along the SHF is focused on high mountainous areas, where the orographic barrier forces out > 80\% of the annual precipitation. AFT cooling ages reveal a coincidence between rapid erosion and exhumation that is focused in a similar to 50-70-km-wide sector of the Himalaya, rather than encompassing the entire orogen. Assuming simplified constant exhumation rates, the rocks of two age vs. elevation transects were exhumed at similar to 1.4 +/- 0.2 and similar to 1.1 +/- 0.4 mm/a with an average cooling rate of similar to 40-50degreesC/Ma during Pliocene-Quarternary time. Following other recently published hypotheses regarding the relation between tectonics and climate in the Himalaya, we suggest that this concentrated loss of material was accommodated by motion along a back-stepping thrust to the south and a normal fault zone to the north as part of an extruding wedge. Climatically controlled erosional processes focus on this wedge and suggest that climatically controlled surface processes determine tectonic deformation in the internal part of the Himalaya. (C) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{ThiedeArrowsmithBookhagenetal.2005,
  author    = {Thiede, Rasmus Christoph and Arrowsmith, J. Ram{\´o}n and Bookhagen, Bodo and McWilliams, Michael O. and Sobel, Edward and Strecker, Manfred},
  title     = {From tectonically to erosionally controlled development of the Himalayan orogen},
  issn      = {0091-7613},
  year      = {2005},
  abstract  = {Whether variations in the spatial distribution of erosion influence the location, style, and magnitude of deformation within the Himalayan orogen is a matter of debate. We report new Ar-40/Ar-39 white mica and apatite fission- track (AFT) ages that measure the vertical component of exhumation rates along an similar to 120-km-wide NE-SW transect spanning the greater Sutlej region of northwest India. The Ar-40/Ar-39 data indicate that first the High Himalayan Crystalline units cooled below their closing temperature during the early to middle Miocene. Subsequently, Lesser Himalayan Crystalline nappes cooled rapidly, indicating southward propagation of the orogen during late Miocene to Pliocene time. The AFT data, in contrast, imply synchronous exhumation of a NE-SW-oriented similar to 80 x 40 km region spanning both crystalline nappes during the Pliocene-Quaternary. The locus of pronounced exhumation defined by the AFT data correlates with a region of high precipitation, discharge, and sediment flux rates during the Holocene. This correlation suggests that although tectonic processes exerted the dominant control on the denudation pattern before and until the middle Miocene; erosion may have been the most important factor since the Pliocene},
  language  = {en}
}
@article{BookhagenThiedeStrecker2005,
  author    = {Bookhagen, Bodo and Thiede, Rasmus Christoph and Strecker, Manfred},
  title     = {Late Quaternary intensified monsoon phases control landscape evolution in the northwest Himalaya},
  issn      = {0091-7613},
  year      = {2005},
  abstract  = {The intensity of the Asian summer-monsoon circulation varies over decadal to millennial time scales and is reflected in changes in surface processes, terrestrial environments, and marine sediment records. However, the mechanisms of long-lived (2-5 k.y.) intensified monsoon phases, the related changes in precipitation distribution, and their effect on landscape evolution and sedimentation rates are not yet well understood. The and high-elevation sectors of the orogen correspond to a climatically sensitive zone that currently receives rain only during abnormal (i.e., strengthened) monsoon seasons. Analogous to present-day rainfall anomalies, enhanced precipitation during an intensified monsoon phase is expected to have penetrated far into these geomorphic threshold regions where hillslopes are close to the angle of failure. We associate landslide triggering during intensified monsoon phases with enhanced precipitation, discharge, and sediment flux leading to an increase in pore-water pressure, lateral scouring of rivers, and over- steepening of hillslopes, eventually resulting in failure of slopes and exceptionally large mass movements. Here we use lacustrine deposits related to spatially and temporally clustered large landslides (>0.5 km(3)) in the Sutlej Valley region of the northwest Himalaya to calculate sedimentation rates and to infer rainfall patterns during late Pleistocene (29-24 ka) and Holocene (10-4 ka) intensified monsoon phases. Compared to present-day sediment-flux measurements, a fivefold increase in sediment-transport rates recorded by sediments in landslide-dammed lakes characterized these episodes of high climatic variability. These changes thus emphasize the pronounced imprint of millennial-scale climate change on surface processes and landscape evolution},
  language  = {en}
}
@article{BookhagenThiedeStrecker2005,
  author    = {Bookhagen, Bodo and Thiede, Rasmus Christoph and Strecker, Manfred},
  title     = {Abnormal monsoon years and their control on erosion and sediment flux in the high, and northwest Himalaya},
  year      = {2005},
  abstract  = {The interplay between topography and Indian summer monsoon circulation profoundly controls precipitation distribution, sediment transport, and river discharge along the Southern Himalayan Mountain Front (SHF). The Higher Himalayas form a major orographic barrier that separates humid sectors to the south and and regions to the north. During the Indian summer monsoon, vortices transport moisture from the Bay of Bengal, swirl along the SHF to the northwest, and cause heavy rainfall when colliding with the mountain front. In the eastern and central parts of the Himalaya, precipitation measurements derived from passive microwave analysis (SSM/I) show a strong gradient, with high values at medium elevations and extensive penetration of moisture along major river valleys into the orogen. The end of the monsoonal conveyer belt is near the Sutlej Valley in the NW Himalaya, where precipitation is lower and rainfall maxima move to lower elevations. This region thus comprises a climatic transition zone that is very sensitive to changes in Indian summer monsoon strength. To constrain magnitude, temporal, and spatial distribution of precipitation, we analyzed high-resolution passive microwave data from the last decade and identified an abnormal monsoon year (AMY) in 2002. During the 2002 AMY, violent rainstorms conquered orographic barriers and penetrated far into otherwise and regions in the northwest Himalaya at elevations in excess of 3 km asl. While precipitation in these regions was significantly increased and triggered extensive erosional processes (i.e., debris flows) on sparsely vegetated, steep hillslopes, mean rainfall along the low to medium elevations was not significantly greater in magnitude. This shift may thus play an important role in the overall sediment flux toward the Himalayan foreland. Using extended precipitation and sediment flux records for the last century, we show that these events have a decadal recurrence interval during the present-day monsoon circulation. Hence, episodically occurring AMYs control geomorphic processes primarily in the high-elevation and sectors of the orogen, while annual recurring monsoonal rainfall distribution dominates erosion in the low- to medium- elevation parts along the SHF. (C) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{ThiedeArrowsmithBookhagenetal.2006,
  author    = {Thiede, Rasmus Christoph and Arrowsmith, J. Ram{\´o}n and Bookhagen, Bodo and McWilliams, Michael O. and Sobel, Edward and Strecker, Manfred},
  title     = {Dome formation and extension in the Tethyan Himalaya, Leo Pargil, northwest India},
  doi       = {10.1130/B25872.1},
  year      = {2006},
  abstract  = {Metamorphic dome complexes occur within the internal structures of the northern Himalaya and southern Tibet. Their origin, deformation, and fault displacement patterns are poorly constrained. We report new field mapping, structural data, and cooling ages from the western flank of the Leo Pargil dome in the northwestern Himalaya in an attempt to characterize its post-middle Miocene structural development. The western flank of the dome is characterized by shallow, west-dipping pervasive foliation and WNW-ESE mineral lineation. Shear-sense indicators demonstrate that it is affected by east-west normal faulting that facilitated exhumation of high-grade metamorphic rocks in a contractional setting. Sustained top-to-northwest normal faulting during exhumation is observed in a progressive transition from ductile to brittle deformation. Garnet and kyanite indicate that the Leo Pargil dome was exhumed from the mid-crust. Ar- 40/Ar-39 mica and apatite fission track (AFT) ages constrain cooling and exhumation pathways front 350 to 60 degrees C and suggest that the dome cooled in three stages since the middle Miocene. Ar-40/Ar-39 white mica ages of 16-14 Ma suggest a first phase of rapid cooling and provide minimum estimates for the onset of dome exhumation. AFT ages between 10 and 8 Ma suggest that ductile fault displacement had ceased by then, and AFT track-length data from high-elevation samples indicate that the rate of cooling had decreased significantly. We interpret this to indicate decreased fault displacement along the Leo Pargil shear zone and possibly a transition to the Kaurik-Chango normal fault system between 10 and 6 Ma. AFT ages from lower elevations indicate accelerated cooling since the Pliocene that cannot be related to pure fault displacement, and therefore may reflect more pronounced regionally distributed and erosion-driven exhumation},
  language  = {en}
}
@article{BookhagenEchtlerMelnicketal.2006,
  author    = {Bookhagen, Bodo and Echtler, Helmut Peter and Melnick, Daniel and Strecker, Manfred and Spencer, Joel Q. G.},
  title     = {Using uplifted Holocene beach berms for paleoseismic analysis on the Santa Maria Island, south-central Chile},
  issn      = {0094-8276},
  doi       = {10.1029/2006gl026734},
  year      = {2006},
  abstract  = {Major earthquakes ( M > 8) have repeatedly ruptured the Nazca-South America plate interface of south-central Chile involving meter scale land-level changes. Earthquake recurrence intervals, however, extending beyond limited historical records are virtually unknown, but would provide crucial data on the tectonic behavior of forearcs. We analyzed the spatiotemporal pattern of Holocene earthquakes on Santa Maria Island (SMI; 37 degrees S), located 20 km off the Chilean coast and approximately 70 km east of the trench. SMI hosts a minimum of 21 uplifted beach berms, of which a subset were dated to calculate a mean uplift rate of 2.3 +/- 0.2 m/ky and a tilting rate of 0.022 +/- 0.002 degrees/ky. The inferred recurrence interval of strandline-forming earthquakes is similar to 180 years. Combining coseismic uplift and aseismic subsidence during an earthquake cycle, the net gain in strandline elevation in this environment is similar to 0.4 m per event},
  language  = {en}
}