TY - INPR A1 - Heimsath, Arjun M. A1 - Korup, Oliver T1 - Quantifying rates and processes of landscape evolution T2 - Earth surface processes and landforms : the journal of the British Geomorphological Research Group Y1 - 2012 U6 - https://doi.org/10.1002/esp.2251 SN - 0197-9337 VL - 37 IS - 2 SP - 249 EP - 251 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Korup, Oliver T1 - Earth's portfolio of extreme sediment transport events JF - Earth science reviews : the international geological journal bridging the gap between research articles and textbooks N2 - Quantitative estimates of sediment flux and the global cycling of sediments from hillslopes to rivers, estuaries, deltas, continental shelves, and deep-sea basins have a long research tradition. In this context, extremely large and commensurately rare sediment transport events have so far eluded a systematic analysis. To start filling this knowledge gap I review some of the highest reported sediment yields in mountain rivers impacted by volcanic eruptions, earthquake- and storm-triggered landslide episodes, and catastrophic dam breaks. Extreme specific yields, defined here as those exceeding the 95th percentile of compiled data, are similar to 10(4) t km(-2) yr(-1) if averaged over 1 yr. These extreme yields vary by eight orders of magnitude, but systematically decay with reference intervals from minutes to millennia such that yields vary by three orders of magnitude for a given reference interval. Sediment delivery from natural dam breaks and pyroclastic eruptions dominate these yields for a given reference interval. Even if averaged over 10(2)-10(3) yr, the contribution of individual disturbances may remain elevated above corresponding catchment denudation rates. I further estimate rates of sediment (re-)mobilisation by individual giant terrestrial and submarine mass movements. Less than 50 postglacial submarine mass movements have involved an equivalent of similar to 10% of the contemporary annual global flux of fluvial sediment to Earth's oceans, while mobilisation rates by individual events rival the decadal-scale sediment discharge from tectonically active orogens such as Taiwan or New Zealand. Sediment flushing associated with catastrophic natural dam breaks is non-stationary and shows a distinct kink at the last glacial-interglacial transition, owing to the drainage of very large late Pleistocene ice-marginal lakes. Besides emphasising the contribution of high-magnitude and low-frequency events to the global sediment cascade, these findings stress the importance of sediment storage for fuelling rather than buffering high sediment transport rates. KW - Sediment yield KW - Erosion KW - Extreme event Y1 - 2012 U6 - https://doi.org/10.1016/j.earscirev.2012.02.006 SN - 0012-8252 VL - 112 IS - 3-4 SP - 115 EP - 125 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Fan, Xuanmei A1 - van Westen, Cees J. A1 - Korup, Oliver A1 - Gorum, Tolga A1 - Xu, Qiang A1 - Dai, Fuchu A1 - Huang, Runqiu A1 - Wang, Gonghui T1 - Transient water and sediment storage of the decaying landslide dams induced by the 2008 Wenchuan earthquake, China JF - Geomorphology : an international journal on pure and applied geomorphology N2 - Earthquake-triggered landslide dams are potentially dangerous disrupters of water and sediment flux in mountain rivers, and capable of releasing catastrophic outburst flows to downstream areas. We analyze an inventory of 828 landslide dams in the Longmen Shan mountains, China, triggered by the M-w 7.9 2008 Wenchuan earthquake. This database is unique in that it is the largest of its kind attributable to a single regional-scale triggering event: 501 of the spatially clustered landslides fully blocked rivers, while the remainder only partially obstructed or diverted channels in steep watersheds of the hanging wall of the Yingxiu-Beichuan Fault Zone. The size distributions of the earthquake-triggered landslides, landslide dams, and associated lakes (a) can be modeled by an inverse gamma distribution; (b) show that moderate-size slope failures caused the majority of blockages; and (c) allow a detailed assessment of seismically induced river-blockage effects on regional water and sediment storage. Monte Carlo simulations based on volumetric scaling relationships for soil and bedrock failures respectively indicate that 14% (18%) of the estimated total coseismic landslide volume of 6.4 (14.6) x 10(9) m(3) was contained in landslide dams, representing only 1.4% of the >60,000 slope failures attributed to the earthquake. These dams have created storage capacity of similar to 0.6x 10(9) m(3) for incoming water and sediment. About 25% of the dams containing 2% of the total river-blocking debris volume failed one week after the earthquake; these figures had risen to 60% (similar to 20%), and >90% (>90%) within one month, and one:year, respectively, thus also emptying similar to 92% of the total potential water and sediment storage behind these, dams within one year following the earthquake. Currently only similar to 0.08 x 10(9) m(3) remain available as natural reservoirs for storing water and sediment, while similar to 0.19 x 10(9) m(3), i.e. about a third of the total river-blocking debris volume, has been eroded by rivers. Dam volume and upstream catchment area control to first order the longevity of the barriers, and bivariate domain plots are consistent with the observation that most earthquake-triggered landslide dams were ephemeral. We conclude that the river-blocking portion of coseismic slope failures disproportionately modulates the post-seismic sediment flux in the Longmen Shan on annual to decadal timescales. KW - Landslide dam KW - Earthquake KW - Magnitude and frequency KW - Sediment budget Y1 - 2012 U6 - https://doi.org/10.1016/j.geomorph.2012.05.003 SN - 0169-555X VL - 171 SP - 58 EP - 68 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Uhlmann, Manuela A1 - Korup, Oliver A1 - Huggel, Christian A1 - Fischer, Luzia A1 - Kargel, Jeffrey S. T1 - Supra-glacial deposition and flux of catastrophic rock-slope failure debris, south-central Alaska JF - Earth surface processes and landforms : the journal of the British Geomorphological Research Group N2 - The ongoing debate over the effects of global environmental change on Earth's cryosphere calls for detailed knowledge about process rates and their variability in cold environments. In this context, appraisals of the coupling between glacier dynamics and para-glacial erosion rates in tectonically active mountains remain rare. We contribute to filling this knowledge gap and present an unprecedented regional-scale inventory of supra-glacial sediment flux and hillslope erosion rates inferred from an analysis of 123 large (> 0 center dot 1km2) catastrophic bedrock landslides that fell onto glaciers in the Chugach Mountains, Alaska, as documented by satellite images obtained between 1972 to 2008. Assuming these supra-glacial landslide deposits to be passive strain markers we infer minimum decadal-scale sediment yields of 190 to 7400tkm-2yr-1 for a given glacier-surface cross-section impacted by episodic rock-slope failure. These rates compare to reported fluvial sediment yields in many mountain rivers, but are an order of magnitude below the extreme sediment yields measured at the snouts of Alaskan glaciers, indicating that the bulk of debris discharged derives from en-glacial, sub-glacial or ice-proximal sources. We estimate an average minimum para-glacial erosion rate by large, episodic rock-slope failures at 0 center dot 5-0 center dot 7mmyr-1 in the Chugach Mountains over a 50-yr period, with earthquakes likely being responsible for up to 73% of this rate. Though ranking amongst the highest decadal landslide erosion rates for this size of study area worldwide, our inferred rates of hillslope erosion in the Chugach Mountains remain an order of magnitude below the pace of extremely rapid glacial sediment export and glacio-isostatic surface uplift previously reported from the region. KW - glacier KW - landslide KW - erosion rate KW - sediment yield KW - Alaska Y1 - 2013 U6 - https://doi.org/10.1002/esp.3311 SN - 0197-9337 VL - 38 IS - 7 SP - 675 EP - 682 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Hoffmann, Thomas A1 - Schlummer, Manuela A1 - Notebaert, Bastiaan A1 - Verstraeten, Gert A1 - Korup, Oliver T1 - Carbon burial in soil sediments from Holocene agricultural erosion, Central Europe JF - Global biogeochemical cycles N2 - Natural and human-induced erosion supplies high amounts of soil organic carbon (OC) to terrestrial drainage networks. Yet OC fluxes in rivers were considered in global budgets only recently. Modern estimates of annual carbon burial in inland river sediments of 0.6 Gt C, or 22% of C transferred from terrestrial ecosystems to river channels, consider only lakes and reservoirs and disregard any long-term carbon burial in hillslope or floodplain sediments. Here we present the first assessment of sediment-bound OC storage in Central Europe from a synthesis of similar to 1500 Holocene hillslope and floodplain sedimentary archives. We show that sediment storage increases with drainage-basin size due to more extensive floodplains in larger river basins. However, hillslopes retain hitherto unrecognized high amounts of eroded soils at the scale of large river basins such that average agricultural erosion rates during the Holocene would have been at least twice as high as reported previously. This anthropogenic hillslope sediment storage exceeds floodplain storage in drainage basins <10(5) km(2), challenging the notion that floodplains are the dominant sedimentary sinks. In terms of carbon burial, OC concentrations in floodplains exceed those on hillslopes, and net OC accumulation rates in floodplains (0.70.2 g C m(-2)a(-1)) surpass those on hillslopes (0.40.1 g C m(-2)a(-1)) over the last 7500 years. We conclude that carbon burial in floodplains and on hillslopes in Central Europe exceeds terrestrial carbon storage in lakes and reservoirs by at least 2 orders of magnitude and should thus be considered in continental carbon budgets. KW - soil organic carbon KW - human impact KW - soil erosion KW - hillslope KW - floodplain KW - deposition Y1 - 2013 U6 - https://doi.org/10.1002/gbc.20071 SN - 0886-6236 SN - 1944-9224 VL - 27 IS - 3 SP - 828 EP - 835 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Blöthe, Jan Henrik A1 - Korup, Oliver T1 - Millennial lag times in the Himalayan sediment routing system JF - Earth & planetary science letters N2 - Any understanding of sediment routing from mountain belts to their forelands and offshore sinks remains incomplete without estimates of intermediate storage that decisively buffers sediment yields from erosion rates, attenuates water and sediment fluxes, and protects underlying bedrock from incision. We quantify for the first time the sediment stored in > 38000 mainly postglacial Himalayan valley fills, based on an empirical volume-area scaling of valley-fill outlines automatically extracted from digital topographic data. The estimated total volume of 690(+452/-242) km(3) is mostly contained in few large valley fills > 1 km(3), while catastrophic mass wasting adds another 177(31) km(3). Sediment storage volumes are highly disparate along the strike of the orogen. Much of the Himalaya's stock of sediment is sequestered in glacially scoured valleys that provide accommodation space for similar to 44% of the total volume upstream of the rapidly exhuming and incising syntaxes. Conversely, the step-like long-wave topography of the central Himalayas limits glacier extent, and thus any significant glacier-derived storage of sediment away from tectonic basins. We show that exclusive removal of Himalayan valley fills could nourish contemporary sediment flux from the Indus and Brahmaputra basins for > 1 kyr, though individual fills may attain residence times of > 100 kyr. These millennial lag times in the Himalayan sediment routing system may sufficiently buffer signals of short-term seismic as well as climatic disturbances, thus complicating simple correlation and interpretation of sedimentary archives from the Himalayan orogen, its foreland, and its submarine fan systems. (C) 2013 Elsevier B.V. All rights reserved. KW - sediment storage KW - Himalayas KW - sediment budget KW - tectonic geomorphology KW - geomorphometry Y1 - 2013 U6 - https://doi.org/10.1016/j.epsl.2013.08.044 SN - 0012-821X SN - 1385-013X VL - 382 IS - 20 SP - 38 EP - 46 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schwanghart, Wolfgang A1 - Worni, Raphael A1 - Huggel, Christian A1 - Stoffel, Markus A1 - Korup, Oliver T1 - Uncertainty in the Himalayan energy–water nexus BT - estimating regional exposure to glacial lake outburst floods JF - Environmental research letters : ERL N2 - Himalayan water resources attract a rapidly growing number of hydroelectric power projects (HPP) to satisfy Asia's soaring energy demands. Yet HPP operating or planned in steep, glacier-fed mountain rivers face hazards of glacial lake outburst floods (GLOFs) that can damage hydropower infrastructure, alter water and sediment yields, and compromise livelihoods downstream. Detailed appraisals of such GLOF hazards are limited to case studies, however, and a more comprehensive, systematic analysis remains elusive. To this end we estimate the regional exposure of 257 Himalayan HPP to GLOFs, using a flood-wave propagation model fed by Monte Carlo-derived outburst volumes of >2300 glacial lakes. We interpret the spread of thus modeled peak discharges as a predictive uncertainty that arises mainly from outburst volumes and dam-breach rates that are difficult to assess before dams fail. With 66% of sampled HPP are on potential GLOF tracks, up to one third of these HPP could experience GLOF discharges well above local design floods, as hydropower development continues to seek higher sites closer to glacial lakes. We compute that this systematic push of HPP into headwaters effectively doubles the uncertainty about GLOF peak discharge in these locations. Peak discharges farther downstream, in contrast, are easier to predict because GLOF waves attenuate rapidly. Considering this systematic pattern of regional GLOF exposure might aid the site selection of future Himalayan HPP. Our method can augment, and help to regularly update, current hazard assessments, given that global warming is likely changing the number and size of Himalayan meltwater lakes. KW - Himalayas KW - glacial hazards KW - glacial lake outburst floods KW - hydropower KW - water resources Y1 - 2016 U6 - https://doi.org/10.1088/1748-9326/11/7/074005 SN - 1748-9326 VL - 11 PB - IOP Publ. CY - Bristol ER -