@article{AcostaSchildgenClarkeetal.2015,
  author    = {Acosta, Veronica Torres and Schildgen, Taylor F. and Clarke, Brian A. and Scherler, Dirk and Bookhagen, Bodo and Wittmann, Hella and von Blanckenburg, Friedhelm and Strecker, Manfred},
  title     = {Effect of vegetation cover on millennial-scale landscape denudation rates in East Africa},
  series = {Lithosphere},
  volume    = {7},
  journal   = {Lithosphere},
  number    = {4},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {1941-8264},
  doi       = {10.1130/L402.1},
  pages     = {408 -- 420},
  year      = {2015},
  abstract  = {The mechanisms by which climate and vegetation affect erosion rates over various time scales lie at the heart of understanding landscape response to climate change. Plot-scale field experiments show that increased vegetation cover slows erosion, implying that faster erosion should occur under low to moderate vegetation cover. However, demonstrating this concept over long time scales and across landscapes has proven to be difficult, especially in settings complicated by tectonic forcing and variable slopes. We investigate this problem by measuring cosmogenic Be-10-derived catchment-mean denudation rates across a range of climate zones and hillslope gradients in the Kenya Rift, and by comparing our results with those published from the Rwenzori Mountains of Uganda. We find that denudation rates from sparsely vegetated parts of the Kenya Rift are up to 0.13 mm/yr, while those from humid and more densely vegetated parts of the Kenya Rift flanks and the Rwenzori Mountains reach a maximum of 0.08 mm/yr, despite higher median hillslope gradients. While differences in lithology and recent land-use changes likely affect the denudation rates and vegetation cover values in some of our studied catchments, hillslope gradient and vegetation cover appear to explain most of the variation in denudation rates across the study area. Our results support the idea that changing vegetation cover can contribute to complex erosional responses to climate or land-use change and that vegetation cover can play an important role in determining the steady-state slopes of mountain belts through its stabilizing effects on the land surface.},
  language  = {en}
}
@article{BufeCookGalyetal.2022,
  author    = {Bufe, Aaron and Cook, Kristen L. and Galy, Albert and Wittmann, Hella and Hovius, Niels},
  title     = {The effect of lithology on the relationship between denudation rate and chemical weathering pathways},
  series = {Earth surface dynamics},
  volume    = {10},
  journal   = {Earth surface dynamics},
  number    = {3},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2196-6311},
  doi       = {10.5194/esurf-10-513-2022},
  pages     = {513 -- 530},
  year      = {2022},
  abstract  = {The denudation of rocks in mountain belts exposes a range of fresh minerals to the surface of the Earth that are chemically weathered by acidic and oxygenated fluids. The impact of the resulting coupling between denudation and weathering rates fundamentally depends on the types of minerals that are weathering. Whereas silicate weathering sequesters CO2, the combination of sulfide oxidation and carbonate dissolution emits CO2 to the atmosphere. Here, we combine the concentrations of dissolved major elements in stream waters with Be-10 basin-wide denudation rates from 35 small catchments in eastern Tibet to elucidate the importance of lithology in modulating the relationships between denudation rate, chemical weathering pathways, and CO2 consumption or release. Our catchments span 3 orders of magnitude in denudation rate in low-grade flysch, high-grade metapelites, and granitoid rocks. For each stream, we estimate the concentrations of solutes sourced from silicate weathering, carbonate dissolution, and sulfide oxidation using a mixing model. We find that for all lithologies, cation concentrations from silicate weathering are largely independent of denudation rate, but solute concentrations from carbonates and, where present, sulfides increase with increasing denudation rate. With increasing denudation rates, weathering may therefore shift from consuming to releasing CO2 in both (meta)sedimentary and granitoid lithologies. For a given denudation rate, we report dissolved solid concentrations and inferred weathering fluxes in catchments underlain by (meta)sedimentary rock that are 2-10 times higher compared to catchments containing granitoid lithologies, even though climatic and topographic parameters do not vary systematically between these catchments. Thus, varying proportions of exposed (meta)sedimentary and igneous rocks during orogenesis could lead to changes in the sequestration and release of CO2 that are independent of denudation rate.},
  language  = {en}
}
@article{DeyThiedeSchildgenetal.2016,
  author    = {Dey, Saptarshi and Thiede, Rasmus Christoph and Schildgen, Taylor F. and Wittmann, Hella and Bookhagen, Bodo and Scherler, Dirk and Jain, Vikrant and Strecker, Manfred},
  title     = {Climate-driven sediment aggradation and incision since the late Pleistocene in the NW Himalaya, India},
  series = {Earth \& planetary science letters},
  volume    = {449},
  journal   = {Earth \& planetary science letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0012-821X},
  doi       = {10.1016/j.epsl.2016.05.050},
  pages     = {321 -- 331},
  year      = {2016},
  abstract  = {Deciphering the response of sediment routing systems to climatic forcing is fundamental for understanding the impacts of climate change on landscape evolution. In the Kangra Basin (northwest Sub-Himalaya, India), upper Pleistocene to Holocene alluvial fills and fluvial terraces record periodic fluctuations of sediment supply and transport capacity on timescales of 10(3) to 10(5) yr. To evaluate the potential influence of climate change on these fluctuations, we compare the timing of aggradation and incision phases recorded within remnant alluvial fans and terraces with climate archives. New surface-exposure dating of six terrace levels with in-situ cosmogenic Be-10 indicates the onset of incision phases. Two terrace surfaces from the highest level (T1) sculpted into the oldest preserved alluvial fan (AF1) date back to 53.4 +/- 3.2 ka and 43.0 +/- 2.7 ka (1 sigma). T2 surfaces sculpted into the remnants of AF1 have exposure ages of 18.6 +/- 1.2 ka and 15.3 +/- 0.9 ka, while terraces sculpted into the upper Pleistocene-Holocene fan (AF2) provide ages of 9.3 +/- 0.4 ka (T3), 7.1 +/- 0.4 ka (T4), 5.2 +/- 0.4 ka (T5) and 3.6 +/- 0.2 ka (T6). Together with previously published OSL ages yielding the timing of aggradation, we find a correlation between variations in sediment transport with oxygen-isotope records from regions affected by the Indian Summer Monsoon. During periods of increased monsoon intensity and post-Last Glacial Maximum glacial retreat, aggradation occurred in the Kangra Basin, likely due to high sediment flux, whereas periods of weakened monsoon intensity or lower sediment supply coincide with incision. (C) 2016 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{DeyThiedeSchildgenetal.2016,
  author    = {Dey, Saptarshi and Thiede, Rasmus Christoph and Schildgen, Taylor F. and Wittmann, Hella and Bookhagen, Bodo and Scherler, Dirk and Strecker, Manfred},
  title     = {Holocene internal shortening within the northwest Sub-Himalaya: Out-of-sequence faulting of the Jwalamukhi Thrust, India},
  series = {Tectonics},
  volume    = {35},
  journal   = {Tectonics},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {0278-7407},
  doi       = {10.1002/2015TC004002},
  pages     = {2677 -- 2697},
  year      = {2016},
  abstract  = {The southernmost thrust of the Himalayan orogenic wedge that separates the foreland from the orogen, the Main Frontal Thrust, is thought to accommodate most of the ongoing crustal shortening in the Sub-Himalaya. Steepened longitudinal river profile segments, terrace offsets, and back-tilted fluvial terraces within the Kangra reentrant of the NW Sub-Himalaya suggest Holocene activity of the Jwalamukhi Thrust (JMT) and other thrust faults that may be associated with strain partitioning along the toe of the Himalayan wedge. To assess the shortening accommodated by the JMT, we combine morphometric terrain analyses with in situ Be-10-based surface-exposure dating of the deformed terraces. Incision into upper Pleistocene sediments within the Kangra Basin created two late Pleistocene terrace levels (T1 and T2). Subsequent early Holocene aggradation shortly before similar to 10ka was followed by episodic reincision, which created four cut-and-fill terrace levels, the oldest of which (T3) was formed at 10.10.9ka. A vertical offset of 445m of terrace T3 across the JMT indicates a shortening rate of 5.60.8 to 7.51.1mma(-1) over the last similar to 10ka. This result suggests that thrusting along the JMT accommodates 40-60\% of the total Sub-Himalayan shortening in the Kangra reentrant over the Holocene. We speculate that this out-of-sequence shortening may have been triggered or at least enhanced by late Pleistocene and Holocene erosion of sediments from the Kangra Basin.},
  language  = {en}
}
@article{MunackKorupResentinietal.2014,
  author    = {Munack, Henry and Korup, Oliver and Resentini, Alberto and Limonta, Mara and Garzanti, Eduardo and Bloethe, Jan H. and Scherler, Dirk and Wittmann, Hella and Kubik, Peter W.},
  title     = {Postglacial denudation of western Tibetan Plateau margin outpaced by long-term exhumation},
  series = {Geological Society of America bulletin},
  volume    = {126},
  journal   = {Geological Society of America bulletin},
  number    = {11-12},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {0016-7606},
  doi       = {10.1130/B30979.1},
  pages     = {1580 -- 1594},
  year      = {2014},
  abstract  = {The Indus River, one of Asia's premier rivers, drains the western Tibetan Plateau and the Nanga Parbat syntaxis. These two areas juxtapose some of the lowest and highest topographic relief and commensurate denudation rates in the Himalaya-Tibet orogen, respectively, yet the spatial pattern of denudation rates upstream of the syntaxis remains largely unclear, as does the way in which major rivers drive headward incision into the Tibetan Plateau. We report a new inventory of Be-10-based basinwide denudation rates from 33 tributaries flanking the Indus River along a 320 km reach across the western Tibetan Plateau margin. We find that denudation rates of up to 110 mm k.y.(-1) in the Ladakh and Zanskar Ranges systematically decrease eastward to 10 mm k.y.(-1) toward the Tibetan Plateau. Independent results from bulk petrographic and heavy mineral analyses support this denudation gradient. Assuming that incision along the Indus exerts the base-level control on tributary denudation rates, our data show a systematic eastward decrease of landscape downwearing, reaching its minimum on the Tibetan Plateau. In contrast, denudation rates increase rapidly 150-200 km downstream of a distinct knick-point that marks the Tibetan Plateau margin in the Indus River longitudinal profile. We infer that any vigorous headward incision and any accompanying erosional waves into the interior of the plateau mostly concerned reaches well below this plateau margin. Moreover, reported long-term (>10(6) yr) exhumation rates from low-temperature chronometry of 0.1-0.75 mm yr(-1) consistently exceed our Be-10-derived denudation rates. With averaging time scales of 10(3)-10(4) yr for our denudation data, we report postglacial rates of downwearing in a tectonically idle landscape. To counterbalance this apparent mismatch, denudation rates must have been higher in the Quaternary during glacial-interglacial intervals.},
  language  = {en}
}
@article{PingelSchildgenStreckeretal.2019,
  author    = {Pingel, Heiko and Schildgen, Taylor F. and Strecker, Manfred and Wittmann, Hella},
  title     = {Pliocene-Pleistocene orographic control on denudation in northwest Argentina},
  series = {Geology},
  volume    = {47},
  journal   = {Geology},
  number    = {4},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {0091-7613},
  doi       = {10.1130/G45800.1},
  pages     = {359 -- 362},
  year      = {2019},
  abstract  = {The intermontane Humahuaca Basin in the Eastern Cordillera of the northwest Argentine Andes lies leeward of an orographic barrier to easterly derived moisture. An average of >2000 mm/yr of rainfall along the eastern flanks of the barrier contrasts with <200 mm/yr in the orogen interior. Paleoenvironmental reconstructions suggest that the basin became disconnected from the foreland during the Miocene-Pliocene by the growth of fault-bounded mountain ranges. Fossil records, sedimentology, and stable isotope data imply that rerouting of the fluvial network by 4.2 Ma and reduced rainfall by ca. 3 Ma were consequences of that range uplift. Here, we present cosmogenic nuclide-derived (Be-10) paleodenudation rates from 6 to 2 Ma fluvial deposits collected from the Humahuaca Basin. Despite increased tectonic activity, our Be-10 data show a tenfold decrease in denudation rates at ca. 3 Ma, documenting a link between uplift-induced semiarid conditions and decreasing hillslope denudation rates. This new data set thus demonstrates the influence of hydrological change on spatiotemporal denudation patterns in tectonically active mountain areas.},
  language  = {en}
}
@article{RepaschWittmannScheingrossetal.2020,
  author    = {Repasch, Marisa and Wittmann, Hella and Scheingross, Joel S. and Sachse, Dirk and Szupiany, Ricardo and Orfeo, Oscar and Fuchs, Margret and Hovius, Niels},
  title     = {Sediment Transit Time and Floodplain Storage Dynamics in Alluvial Rivers Revealed by Meteoric 10Be},
  series = {Journal of Geophysical Research: Earth Surface},
  volume    = {125},
  journal   = {Journal of Geophysical Research: Earth Surface},
  publisher = {Wiley},
  address   = {Hoboken, NJ},
  issn      = {2169-9011},
  doi       = {10.1029/2019JF005419},
  pages     = {19},
  year      = {2020},
  abstract  = {Quantifying the time scales of sediment transport and storage through river systems is fundamental for understanding weathering processes, biogeochemical cycling, and improving watershed management, but measuring sediment transit time is challenging. Here we provide the first systematic test of measuring cosmogenic meteoric Beryllium-10 (10Bem) in the sediment load of a large alluvial river to quantify sediment transit times. We take advantage of a natural experiment in the Rio Bermejo, a lowland alluvial river traversing the east Andean foreland basin in northern Argentina. This river has no tributaries along its trunk channel for nearly 1,300 km downstream from the mountain front. We sampled suspended sediment depth profiles along the channel and measured the concentrations of 10Bem in the chemically extracted grain coatings. We calculated depth-integrated 10Bem concentrations using sediment flux data and found that 10Bem concentrations increase 230\% from upstream to downstream, indicating a mean total sediment transit time of 8.4 ± 2.2 kyr. Bulk sediment budget-based estimates of channel belt and fan storage times suggest that the 10Bem tracer records mixing of old and young sediment reservoirs. On a reach scale, 10Bem transit times are shorter where the channel is braided and superelevated above the floodplain, and longer where the channel is incised and meandering, suggesting that transit time is controlled by channel morphodynamics. This is the first systematic application of 10Bem as a sediment transit time tracer and highlights the method's potential for inferring sediment routing and storage dynamics in large river systems.},
  language  = {en}
}
@misc{RepaschWittmannScheingrossetal.2020,
  author    = {Repasch, Marisa and Wittmann, Hella and Scheingross, Joel S. and Sachse, Dirk and Szupiany, Ricardo and Orfeo, Oscar and Fuchs, Margret and Hovius, Niels},
  title     = {Sediment Transit Time and Floodplain Storage Dynamics in Alluvial Rivers Revealed by Meteoric 10Be},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1119},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-49432},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-494324},
  pages     = {21},
  year      = {2020},
  abstract  = {Quantifying the time scales of sediment transport and storage through river systems is fundamental for understanding weathering processes, biogeochemical cycling, and improving watershed management, but measuring sediment transit time is challenging. Here we provide the first systematic test of measuring cosmogenic meteoric Beryllium-10 (10Bem) in the sediment load of a large alluvial river to quantify sediment transit times. We take advantage of a natural experiment in the Rio Bermejo, a lowland alluvial river traversing the east Andean foreland basin in northern Argentina. This river has no tributaries along its trunk channel for nearly 1,300 km downstream from the mountain front. We sampled suspended sediment depth profiles along the channel and measured the concentrations of 10Bem in the chemically extracted grain coatings. We calculated depth-integrated 10Bem concentrations using sediment flux data and found that 10Bem concentrations increase 230\% from upstream to downstream, indicating a mean total sediment transit time of 8.4 ± 2.2 kyr. Bulk sediment budget-based estimates of channel belt and fan storage times suggest that the 10Bem tracer records mixing of old and young sediment reservoirs. On a reach scale, 10Bem transit times are shorter where the channel is braided and superelevated above the floodplain, and longer where the channel is incised and meandering, suggesting that transit time is controlled by channel morphodynamics. This is the first systematic application of 10Bem as a sediment transit time tracer and highlights the method's potential for inferring sediment routing and storage dynamics in large river systems.},
  language  = {en}
}
@article{RosenkranzSchildgenWittmannetal.2017,
  author    = {Rosenkranz, Ruben and Schildgen, Taylor F. and Wittmann, Hella and Spiegel, Cornelia},
  title     = {Coupling erosion and topographic development in the rainiest place on Earth},
  series = {Earth \& planetary science letters},
  volume    = {483},
  journal   = {Earth \& planetary science letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0012-821X},
  doi       = {10.1016/j.epsl.2017.11.047},
  pages     = {39 -- 51},
  year      = {2017},
  abstract  = {The uplift of the Shillong Plateau, in northeast India between the Bengal floodplain and the Himalaya Mountains, has had a significant impact on regional precipitation patterns, strain partitioning, and the path of the Brahmaputra River. Today, the plateau receives the highest measured yearly rainfall in the world and is tectonically active, having hosted one of the strongest intra-plate earthquakes ever recorded. Despite the unique tectonic and climatic setting of this prominent landscape feature, its exhumation and surface uplift history are poorly constrained. We collected 14 detrital river sand and 3 bedrock samples from the southern margin of the Shillong Plateau to measure erosion rates using the terrestrial cosmogenic nuclide 10Be. The calculated bedrock erosion rates range from 2.0 to 5.6 m My-1, whereas catchment average erosion rates from detrital river sands range from 48 to 214 m My-1. These rates are surprisingly low in the context of steep, tectonically active slopes and extreme rainfall. Moreover, the highest among these rates, which occur on the low-relief plateau surface, appear to have been affected by anthropogenic land-use change. To determine the onset of surface uplift, we coupled the catchment averaged erosion rates with topographic analyses of the plateau's southern margin. We interpolated an inclined, pre-incision surface from minimally eroded remnants along the valley interfluves and calculated the eroded volume of the valleys carved beneath the surface. The missing volume was then divided by the volume flux derived from the erosion rates to obtain the onset of uplift. The results of this calculation, ranging from 3.0 to 5.0 Ma for individual valleys, are in agreement with several lines of stratigraphic evidence from the Brahmaputra and Bengal basin that constrain the onset of topographic uplift, specifically the onset of flexural loading and the transgression from deltaic to marine deposition. Ultimately, our data corroborate the hypothesis that surface uplift was decoupled from the onset of rapid exhumation, which occurred several millions of years earlier.},
  language  = {en}
}
@article{SaviSchildgenTofeldeetal.2016,
  author    = {Savi, Sara and Schildgen, Taylor F. and Tofelde, Stefanie and Wittmann, Hella and Scherler, Dirk and Mey, J{\"u}rgen and Alonso, Ricardo N. and Strecker, Manfred},
  title     = {Climatic controls on debris-flow activity and sediment aggradation: The Del Medio fan, NW Argentina},
  series = {Journal of geophysical research : Earth surface},
  volume    = {121},
  journal   = {Journal of geophysical research : Earth surface},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {2169-9003},
  doi       = {10.1002/2016JF003912},
  pages     = {2424 -- 2445},
  year      = {2016},
  abstract  = {In the Central Andes, several studies on alluvial terraces and valley fills have linked sediment aggradation to periods of enhanced sediment supply. However, debate continues over whether tectonic or climatic factors are most important in triggering the enhanced supply. The Del Medio catchment in the Humahuaca Basin (Eastern Cordillera, NW Argentina) is located within a transition zone between subhumid and arid climates and hosts the only active debris-flow fan within this intermontane valley. By combining Be-10 analyses of boulder and sediment samples within the Del Medio catchment, with regional morphometric measurements of nearby catchments, we identify the surface processes responsible for aggradation in the Del Medio fan and their likely triggers. We find that the fan surface has been shaped by debris flows and channel avulsions during the last 400 years. Among potential tectonic, climatic, and autogenic factors that might influence deposition, our analyses point to a combination of several favorable factors that drive aggradation. These are in particular the impact of occasional abundant rainfall on steep slopes in rock types prone to failure, located in a region characterized by relatively low rainfall amounts and limited transport capacity. These characteristics are primarily associated with the climatic transition zone between the humid foreland and the arid orogen interior, which creates an imbalance between sediment supply and sediment transfer. The conditions and processes that drive aggradation in the Del Medio catchment today may provide a modern analog for the conditions and processes that drove aggradation in other nearby tributaries in the past.},
  language  = {en}
}
@article{ScherlerMunackMeyetal.2014,
  author    = {Scherler, Dirk and Munack, Henry and Mey, J{\"u}rgen and Eugster, Patricia and Wittmann, Hella and Codilean, Alexandru T. and Kubik, Peter and Strecker, Manfred},
  title     = {Ice dams, outburst floods, and glacial incision at the western margin of the Tibetan Plateau: A > 100 k.y. chronology from the Shyok Valley, Karakoram},
  series = {Geological Society of America bulletin},
  volume    = {126},
  journal   = {Geological Society of America bulletin},
  number    = {5-6},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {0016-7606},
  doi       = {10.1130/B30942.1},
  pages     = {738 -- 758},
  year      = {2014},
  abstract  = {Some of the largest and most erosive floods on Earth result from the failure of glacial dams. While potentially cataclysmic ice dams are recognized to have repeatedly formed along ice-sheet margins, much less is known about the frequency and longevity of ice dams caused by mountain glaciers, and their impact on landscape evolution. Here we present field observations and results from cosmogenic nuclide dating that allow reconstructing a > 100-k.y.-long history of glacial damming in the Shyok Valley, eastern Karakoram (South Asia). Our field observations provide evidence that Asia's second-longest glacier, the Siachen, once extended for over 180 km and blocked the Shyok River during the penultimate glacial period, leading to upstream deposition of a more than 400-m-thick fluvio-lacustrine valley fill. Be-10-depth profile modeling indicates that glacial damming ended with the onset of the Eemian interglacial and that the Shyok River subsequently incised the valley fill at an average rate of similar to 4-7 m k.y.(-1). Comparison with contemporary ice-dammed lakes in the Karakoram and elsewhere suggests recurring outburst floods during the aggradation period, while over 25 cycles of fining-upward lake deposits within the valley fill indicate impounding of floods from farther upstream. Despite prolonged damming, the net effect of this and probably earlier damming episodes by the Siachen Glacier is dominated by glacial erosion in excess of fluvial incision, as evidenced by a pronounced overdeepening that follows the glaciated valley reach. Strikingly similar overdeepened valleys at all major confluences of the Shyok and Indus Rivers with Karakoram tributaries indicate that glacial dams and subsequent outburst floods have been widespread and frequent in this region during the Quaternary. Our study suggests that the interaction of Karakoram glaciers with the Shyok and Indus Rivers promoted valley incision and headward erosion into the western margin of the Tibetan Plateau.},
  language  = {en}
}
@article{SchildgenCosentinoBookhagenetal.2012,
  author    = {Schildgen, Taylor F. and Cosentino, D. and Bookhagen, Bodo and Niedermann, Samuel and Yildirim, C. and Echtler, Helmut Peter and Wittmann, Hella and Strecker, Manfred},
  title     = {Multi-phased uplift of the southern margin of the Central Anatolian plateau, Turkey a record of tectonic and upper mantle processes},
  series = {Earth \& planetary science letters},
  volume    = {317},
  journal   = {Earth \& planetary science letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0012-821X},
  doi       = {10.1016/j.epsl.2011.12.003},
  pages     = {85 -- 95},
  year      = {2012},
  abstract  = {Uplifted Neogene marine sediments and Quaternary fluvial terraces in the Mut Basin, southern Turkey, reveal a detailed history of surface uplift along the southern margin of the Central Anatolian plateau from the Late Miocene to the present. New surface exposure ages (Be-10, Al-26, and Ne-21) of gravels capping fluvial strath terraces located between 28 and 135 m above the Goksu River in the Mut Basin yield ages ranging from ca. 25 to 130 ka, corresponding to an average incision rate of 0.52 to 0.67 mm/yr. Published biostratigraphic data combined with new interpretations of the fossil assemblages from uplifted marine sediments reveal average uplift rates of 0.25 to 0.37 mm/yr since Late Miocene time (starting between 8 and 5.45 Ma), and 0.72 to 0.74 mm/yr after 1.66 to 1.62 Ma. Together with the terrace abandonment ages, the data imply 0.6 to 0.7 mm/yr uplift rates from 1.6 Ma to the present. The different post-Late Miocene and post-1.6 Ma uplift rates can imply increasing uplift rates through time, or multi-phased uplift with slow uplift or subsidence in between. Longitudinal profiles of rivers in the upper catchment of the Mut and Ermenek basins show no apparent lithologic or fault control on some knickpoints that occur at 1.2 to 1.5 km elevation, implying a transient response to a change in uplift rates. Projections of graded upper relict channel segments to the modern outlet, together with constraints from uplifted marine sediments, show that a slower incision/uplift rate of 0.1 to 0.2 mm/yr preceded the 0.7 mm/yr uplift rate. The river morphology and profile projections therefore reflect multi-phased uplift of the plateau margin, rather than steadily increasing uplift rates. Multi-phased uplift can be explained by lithospheric slab break-off and possibly also the arrival of the Eratosthenes Seamount at the collision zone south of Cyprus.},
  language  = {en}
}
@article{StolleSchwanghartAndermannetal.2018,
  author    = {Stolle, Amelie and Schwanghart, Wolfgang and Andermann, Christoff and Bernhardt, Anne and Fort, Monique and Jansen, John D. and Wittmann, Hella and Merchel, Silke and Rugel, Georg and Adhikari, Basanta Raj and Korup, Oliver},
  title     = {Protracted river response to medieval earthquakes},
  series = {Earth surface processes and landforms : the journal of the British Geomorphological Research Group},
  volume    = {44},
  journal   = {Earth surface processes and landforms : the journal of the British Geomorphological Research Group},
  number    = {1},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0197-9337},
  doi       = {10.1002/esp.4517},
  pages     = {331 -- 341},
  year      = {2018},
  abstract  = {Mountain rivers respond to strong earthquakes by rapidly aggrading to accommodate excess sediment delivered by co-seismic landslides. Detailed sediment budgets indicate that rivers need several years to decades to recover from seismic disturbances, depending on how recovery is defined. We examine three principal proxies of river recovery after earthquake-induced sediment pulses around Pokhara, Nepal's second largest city. Freshly exhumed cohorts of floodplain trees in growth position indicate rapid and pulsed sedimentation that formed a fan covering 150 km2 in a Lesser Himalayan basin with tens of metres of debris between the 11th and 15th centuries AD. Radiocarbon dates of buried trees are consistent with those of nearby valley deposits linked to major medieval earthquakes, such that we can estimate average rates of re-incision since. We combine high-resolution digital elevation data, geodetic field surveys, aerial photos, and dated tree trunks to reconstruct geomorphic marker surfaces. The volumes of sediment relative to these surfaces require average net sediment yields of up to 4200 t km-2 yr-1 for the 650 years since the last inferred earthquake-triggered sediment pulse. The lithological composition of channel bedload differs from that of local bedrock, confirming that rivers are still mostly evacuating medieval valley fills, locally incising at rates of up to 0.2 m yr-1. Pronounced knickpoints and epigenetic gorges at tributary junctions further illustrate the protracted fluvial response; only the distal portions of the earthquake-derived sediment wedges have been cut to near their base. Our results challenge the notion that mountain rivers recover speedily from earthquakes within years to decades. The valley fills around Pokhara show that even highly erosive Himalayan rivers may need more than several centuries to adjust to catastrophic perturbations. Our results motivate some rethinking of post-seismic hazard appraisals and infrastructural planning in active mountain regions.},
  language  = {en}
}
@article{TofeldeDuesingSchildgenetal.2018,
  author    = {Tofelde, Stefanie and Duesing, Walter and Schildgen, Taylor F. and Wickert, Andrew D. and Wittmann, Hella and Alonso, Ricardo N. and Strecker, Manfred},
  title     = {Effects of deep-seated versus shallow hillslope processes on cosmogenic Be-10 concentrations in fluvial sand and gravel},
  series = {Earth surface processes and landforms : the journal of the British Geomorphological Research Group},
  volume    = {43},
  journal   = {Earth surface processes and landforms : the journal of the British Geomorphological Research Group},
  number    = {15},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0197-9337},
  doi       = {10.1002/esp.4471},
  pages     = {3086 -- 3098},
  year      = {2018},
  abstract  = {Terrestrial cosmogenic nuclide (TCN) concentrations in fluvial sediment, from which denudation rates are commonly inferred, can be affected by hillslope processes. TCN concentrations in gravel and sand may differ if localized, deep-excavation processes (e.g. landslides, debris flows) affect the contributing catchment, whereas the TCN concentrations of sand and gravel tend to be more similar when diffusional processes like soil creep and sheetwash are dominant. To date, however, no study has systematically compared TCN concentrations in different detrital grain-size fractions with a detailed inventory of hillslope processes from the entire catchment. Here we compare concentrations of the TCN Be-10 in 20 detrital sand samples from the Quebrada del Toro (southern Central Andes, Argentina) to a hillslope-process inventory from each contributing catchment. Our comparison reveals a shift from low-slope gullying and scree production in slowly denuding, low-slope areas to steep-slope gullying and landsliding in fast-denuding, steep areas. To investigate whether the nature of hillslope processes (locally excavating or more uniformly denuding) may be reflected in a comparison of the Be-10 concentrations of sand and gravel, we define the normalized sand-gravel index (NSGI) as the Be-10-concentration difference between sand and gravel divided by their summed concentrations. We find a positive, linear relationship between the NSGI and median slope, such that our NSGI values broadly reflect the shift in hillslope processes from low-slope gullying and scree production to steep-slope gullying and landsliding. Higher NSGI values characterize regions affected by steep-slope gullying or landsliding. We relate the large scatter in the relationship, which is exhibited particularly in low-slope areas, to reduced hillslope-channel connectivity and associated transient sediment storage within those catchments. While high NSGI values in well-connected catchments are a reliable signal of deep-excavation processes, hillslope excavation processes may not be reliably recorded by NSGI values where sediment experiences transient storage. (c) 2018 John Wiley \& Sons, Ltd.},
  language  = {en}
}
@article{TofeldeSchildgenSavietal.2017,
  author    = {Tofelde, Stefanie and Schildgen, Taylor F. and Savi, Sara and Pingel, Heiko and Wickert, Andrew D. and Bookhagen, Bodo and Wittmann, Hella and Alonso, Ricardo N. and Cottle, John and Strecker, Manfred},
  title     = {100 kyr fluvial cut-and-fill terrace cycles since the Middle Pleistocene in the southern Central Andes, NW Argentina},
  series = {Earth \& planetary science letters},
  volume    = {473},
  journal   = {Earth \& planetary science letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0012-821X},
  doi       = {10.1016/j.epsl.2017.06.001},
  pages     = {141 -- 153},
  year      = {2017},
  abstract  = {Fluvial fill terraces in intermontane basins are valuable geomorphic archives that can record tectonically and/or climatically driven changes of the Earth-surface process system. However, often the preservation of fill terrace sequences is incomplete and/or they may form far away from their source areas, complicating the identification of causal links between forcing mechanisms and landscape response, especially over multi-millennial timescales. The intermontane Toro Basin in the southern Central Andes exhibits at least five generations of fluvial terraces that have been sculpted into several-hundred-meter-thick Quaternary valley-fill conglomerates. New surface-exposure dating using nine cosmogenic Be-10 depth profiles reveals the successive abandonment of these terraces with a 100 kyr cyclicity between 75 +/- 7 and 487 +/- 34 ka. Depositional ages of the conglomerates, determined by four Al-26/Be-10 burial samples and U-Pb zircon ages of three intercalated volcanic ash beds, range from 18 +/- 141 to 936 +/- 170 ka, indicating that there were multiple cut-and-fill episodes. Although the initial onset of aggradation at similar to 1 Ma and the overall net incision since ca. 500 ka can be linked to tectonic processes at the narrow basin outlet, the superimposed 100 kyr cycles of aggradation and incision are best explained by eccentricity-driven climate change. Within these cycles, the onset of river incision can be correlated with global cold periods and enhanced humid phases recorded in paleoclimate archives on the adjacent Bolivian Altiplano, whereas deposition occurred mainly during more arid phases on the Altiplano and global interglacial periods. We suggest that enhanced runoff during global cold phases - due to increased regional precipitation rates, reduced evapotranspiration, or both - resulted in an increased sediment-transport capacity in the Toro Basin, which outweighed any possible increases in upstream sediment supply and thus triggered incision. Compared with two nearby basins that record precessional (21-kyr) and long-eccentricity (400-kyr) forcing within sedimentary and geomorphic archives, the recorded cyclicity scales with the square of the drainage basin length. (C) 2017 Elsevier B.V. All rights reserved.},
  language  = {en}
}