TY - JOUR A1 - Korup, Oliver A1 - Görüm, Tolga A1 - Hayakawa, Yuichi T1 - Without power? - Landslide inventories in the face of climate change JF - Earth surface processes and landforms : the journal of the British Geomorphological Research Group N2 - Projected scenarios of climate change involve general predictions about the likely changes to the magnitude and frequency of landslides, particularly as a consequence of altered precipitation and temperature regimes. Whether such landslide response to contemporary or past climate change may be captured in differing scaling statistics of landslide size distributions and the erosion rates derived thereof remains debated. We test this notion with simple Monte Carlo and bootstrap simulations of statistical models commonly used to characterize empirical landslide size distributions. Our results show that significant changes to total volumes contained in such inventories may be masked by statistically indistinguishable scaling parameters, critically depending on, among others, the size of the largest of landslides recorded. Conversely, comparable model parameter values may obscure significant, i.e. more than twofold, changes to landslide occurrence, and thus inferred rates of hillslope denudation and sediment delivery to drainage networks. A time series of some of Earth's largest mass movements reveals clustering near and partly before the last glacial-interglacial transition and a distinct step-over from white noise to temporal clustering around this period. However, elucidating whether this is a distinct signal of first-order climate-change impact on slope stability or simply coincides with a transition from short-term statistical noise to long-term steady-state conditions remains an important research challenge. KW - landslide KW - climate change KW - magnitude & frequency Y1 - 2012 U6 - https://doi.org/10.1002/esp.2248 SN - 0197-9337 VL - 37 IS - 1 SP - 92 EP - 99 PB - Wiley-Blackwell CY - Hoboken 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 - Le Friant, A. A1 - Ishizuka, O. A1 - Boudon, G. A1 - Palmer, M. R. A1 - Talling, P. J. A1 - Villemant, B. A1 - Adachi, T. A1 - Aljahdali, M. A1 - Breitkreuz, C. A1 - Brunet, M. A1 - Caron, B. A1 - Coussens, M. A1 - Deplus, C. A1 - Endo, D. A1 - Feuillet, N. A1 - Fraas, A. J. A1 - Fujinawa, A. A1 - Hart, M. B. A1 - Hatfield, R. G. A1 - Hornbach, M. A1 - Jutzeler, M. A1 - Kataoka, K. S. A1 - Komorowski, J. -C. A1 - Lebas, E. A1 - Lafuerza, S. A1 - Maeno, F. A1 - Manga, M. A1 - Martinez-Colon, M. A1 - McCanta, M. A1 - Morgan, S. A1 - Saito, T. A1 - Slagle, A. A1 - Sparks, S. A1 - Stinton, A. A1 - Stroncik, Nicole A1 - Subramanyam, K. S. V. A1 - Tamura, Yui A1 - Trofimovs, J. A1 - Voight, B. A1 - Wall-Palmer, D. A1 - Wang, F. A1 - Watt, S. F. L. T1 - Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODP Expedition 340 JF - Geochemistry, geophysics, geosystems N2 - IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition and origin of those deposits. Sites U1394, U1399, and U1400 that penetrated landslide deposits recovered exclusively seafloor sediment, comprising mainly turbidites and hemipelagic deposits, and lacked debris avalanche deposits. This supports the concepts that i/ volcanic debris avalanches tend to stop at the slope break, and ii/ widespread and voluminous failures of preexisting low-gradient seafloor sediment can be triggered by initial emplacement of material from the volcano. Offshore Martinique (U1399 and 1400), the landslide deposits comprised blocks of parallel strata that were tilted or microfaulted, sometimes separated by intervals of homogenized sediment (intense shearing), while Site U1394 offshore Montserrat penetrated a flat-lying block of intact strata. The most likely mechanism for generating these large-scale seafloor sediment failures appears to be propagation of a decollement from proximal areas loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation. Under some conditions, volcanic island landslide deposits composed of mainly seafloor sediment will tend to form smaller magnitude tsunamis than equivalent volumes of subaerial block-rich mass flows rapidly entering water. Expedition 340 also successfully drilled sites to access the undisturbed record of eruption fallout layers intercalated with marine sediment which provide an outstanding high-resolution data set to analyze eruption and landslides cycles, improve understanding of magmatic evolution as well as offshore sedimentation processes. KW - landslide KW - volcanic island KW - debris avalanche KW - seafloor sediment failure KW - tsunami KW - IODP Y1 - 2015 U6 - https://doi.org/10.1002/2014GC005652 SN - 1525-2027 VL - 16 IS - 2 SP - 420 EP - 442 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Schönfeldt, Elisabeth A1 - Pánek, Tomáš A1 - Winocur, Diego A1 - Silhan, Karel A1 - Korup, Oliver T1 - Postglacial Patagonian mass movement BT - from rotational slides and spreads to earthflows JF - Geomorphology : an international journal on pure and applied geomorphology N2 - Many of the volcanic plateau margins of the eastern, formerly glaciated, foreland of the Patagonian Andes are undermined by giant landslides (>= 10(8) m(3)). One cluster of such landslides extends along the margin of the Meseta del Lago Buenos Aires (MLBA) plateau that is formed mainly by Neogene-Quaternary basalts. The dry climate is at odds with numerous >2-km long earthflows nested within older and larger compound landslides. We present a hydrological analysis, a detailed geomorphic map, interpretations of exposed landslide interiors, and radiocarbon dating of the El Mirador landslide, which is one of the largest and morphologically most representative landslide. We find that the presence of lakes on top of the plateau, causing low infiltration rates, correlates negatively with the abundance of earthflows on compound landslides along the plateau margins. Field outcrops show that the pattern of compound landslides and earthflows is likely controlled by groundwater seepage at the contact between the basalts and underlying soft Miocene molasse. Numerous peat bogs store water and sediment and are more abundant in earthflow-affected areas than in their contributing catchment areas.
Radiocarbon dates indicate that these earthflows displaced metre-thick layers of peat in the late Holocene (<2.5 ka). We conclude that earthflows of the MLBA plateau might be promising proxies of past hydroclimatic conditions in the Patagonian foreland, if strong earthquakes or gradual crustal stress changes due to glacioisostatic rebound can be ruled out. KW - landslide KW - lateral spread KW - earthflow KW - Patagonia Y1 - 2020 U6 - https://doi.org/10.1016/j.geomorph.2020.107316 SN - 0169-555X SN - 1872-695X VL - 367 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Struck, Martin A1 - Andermann, Christoff A1 - Hovius, Niels A1 - Korup, Oliver A1 - Turowski, Jens M. A1 - Bista, Raj A1 - Pandit, Hari P. A1 - Dahal, Ranjan K. T1 - Monsoonal hillslope processes determine grain size-specific suspended sediment fluxes in a trans-Himalayan river JF - Geophysical research letters N2 - Sediments in rivers record the dynamics of erosion processes. While bulk sediment fluxes are easily and routinely obtained, sediment caliber remains underexplored when inferring erosion mechanisms. Yet sediment grain size distributions may be the key to discriminating their origin. We have studied grain size-specific suspended sediment fluxes in the Kali Gandaki, a major trans-Himalayan river. Two strategically located gauging stations enable tracing of sediment caliber on either side of the Himalayan orographic barrier. The data show that fine sediment input into the northern headwaters is persistent, while coarse sediment comes from the High Himalayas during the summer monsoon. A temporally matching landslide inventory similarly indicates the prominence of monsoon-driven hillslope mass wasting. Thus, mechanisms of sediment supply can leave strong traces in the fluvial caliber, which could project well beyond the mountain front and add to the variability of the sedimentary record of orogen erosion. KW - Himalayas KW - erosion KW - grain size KW - suspended sediments KW - landslide KW - river transport Y1 - 2015 U6 - https://doi.org/10.1002/2015GL063360 SN - 0094-8276 SN - 1944-8007 VL - 42 IS - 7 SP - 2302 EP - 2308 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Weidinger, Johannes T. A1 - Korup, Oliver A1 - Munack, Henry A1 - Altenberger, Uwe A1 - Dunning, Stuart A. A1 - Tippelt, Gerold A1 - Lottermoser, Werner T1 - Giant rockslides from the inside JF - Earth & planetary science letters N2 - The growing body of research on large-scale mass wasting events so far has only scarcely investigated the sedimentology of chaotic deposits from non-volcanic terrestrial landslides such that any overarching and systematic terminological framework remains elusive. Yet recent work has emphasized the need for better understanding the internal structure and composition of rockslide deposits as a means to characterise the mechanics during the final stages of runout and emplacement. We offer a comprehensive overview on the occurrence of rock fragmentation and frictional melt both at different geographic locations, and different sections within large (>10(6) m(3)) rockslide masses. We argue that exposures of pervasively fragmented and interlocked jigsaw-cracked rock masses; basal melange containing rip-up clasts and phantom blocks; micro-breccia; and thin bands of basal frictionite are indispensable clues for identifying deposits from giant rockslides that may remain morphologically inconspicuous otherwise. These sedimentary assemblages are diagnostic tools for distinguishing large rockslide debris from macro and microscopically similar glacial deposits, tectonic fault-zone breccias, and impact breccias, and thus help avoid palaeoclimatic and tectonic misinterpretations, let alone misestimates of the hazard from giant rockslides. Moreover, experimental results from Mossbauer spectroscopy of frictionite samples support visual interpretations of thin sections, and demonstrate that short-lived (<10 s) friction-induced partial melting at temperatures >1500 degrees C in the absence of water occurred at the base of several giant moving rockslides. This finding supports previous theories of dry excess runout accompanied by comminution of rock masses down to gm-scale, and indicates that catastrophic motion of large fragmenting rock masses does not require water as a potential lubricant. KW - landslide KW - petrography KW - frictional melt KW - pseudotachylyte KW - breccia KW - Mossbauer spectroscopy Y1 - 2014 U6 - https://doi.org/10.1016/j.epsl.2013.12.017 SN - 0012-821X SN - 1385-013X VL - 389 SP - 62 EP - 73 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Teshebaeva, Kanayim A1 - Echtler, Helmut A1 - Bookhagen, Bodo A1 - Strecker, Manfred T1 - Deep-seated gravitational slope deformation (DSGSD) and slow-moving landslides in the southern Tien Shan Mountains: new insights from InSAR, tectonic and geomorphic analysis JF - Earth surface processes and landforms : the journal of the British Geomorphological Research Group N2 - We investigated deep-seated gravitational slope deformation (DSGSD) and slow mass movements in the southern Tien Shan Mountains front using synthetic aperture radar (SAR) time-series data obtained by the ALOS/PALSAR satellite. DSGSD evolves with a variety of geomorphological changes (e.g. valley erosion, incision of slope drainage networks) over time that affect earth surfaces and, therefore, often remain unexplored. We analysed 118 interferograms generated from 20 SAR images that covered about 900 km(2). To understand the spatial pattern of the slope movements and to identify triggering parameters, we correlated surface dynamics with the tectono-geomorphic processes and lithologic conditions of the active front of the Alai Range. We observed spatially continuous, constant hillslope movements with a downslope speed of approximately 71 mm year(-1) velocity. Our findings suggest that the lithological and structural framework defined by protracted deformation was the main controlling factor for sustained relief and, consequently, downslope mass movements. The analysed structures revealed integration of a geological/structural setting with the superposition of Cretaceous-Paleogene alternating carbonatic and clastic sedimentary structures as the substratum for younger, less consolidated sediments. This type of structural setting causes the development of large-scale, gravity-driven DSGSD and slow mass movement. Surface deformations with clear scarps and multiple crest lines triggered planes for large-scale deep mass creeps, and these were related directly to active faults and folds in the geologic structures. Our study offers a new combination of InSAR techniques and structural field observations, along with morphometric and seismologic correlations, to identify and quantify slope instability phenomena along a tectonically active mountain front. These results contribute to an improved natural risk assessment in these structures. KW - interferometric SAR (InSAR) KW - small baseline subset (SBAS) KW - gravity-driven slope deformation KW - landslide KW - tectonic geomorphology KW - Tien Shan Mountains Y1 - 2019 U6 - https://doi.org/10.1002/esp.4648 SN - 0197-9337 SN - 1096-9837 VL - 44 IS - 12 SP - 2333 EP - 2348 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Grieve, Stuart W. D. A1 - Hales, Tristram C. A1 - Parker, Robert N. A1 - Mudd, Simon M. A1 - Clubb, Fiona J. T1 - Controls on Zero-Order Basin Morphology JF - Journal of geophysical research : Earth surface N2 - Zero-order basins are common features of soil-mantled landscapes, defined as unchanneled basins at the head of a drainage network. Their geometry and volume control how quickly sediment may reaccumulate after landslide evacuation and, more broadly, zero order basins govern the movement of water and sediment from hillslopes to the fluvial network. They also deliver water and sediment to the uppermost portions of the fluvial network. Despite this role as the moderator between hillslope and fluvial processes, little analysis on their morphology has been conducted at the landscape scale. We present a method to identify zero-order basins in landscapes and subsequently quantify their geometric properties using elliptical Fourier analysis. We deploy this method across the Coweeta Hydrologic Laboratory, USA. Properties such as length, relief, width, and concavity follow distinct probability distributions, which may serve as a basis for testing predictions of future landscape evolution models. Surprisingly, in a landscape with an orographic precipitation gradient and large hillslope to channel relief, we observe no correlation between elevation or spatial location and basin geometry. However, we find that two physiographic units in Coweeta have distinct zero-order basin morphologies. These are the steep, thin soiled, high-elevation Nantahala Escarpment and the lower-gradient, lower-elevation, thick soiled remainder of the basin. Our results indicate that basin slope and area negatively covary, producing the distinct forms observed between the two physiographic units, which we suggest arise through competition between spatially variable soil creep and stochastic landsliding. KW - zero-order basin KW - landslide KW - hillslope geomorphology KW - landscape evolution modeling KW - lidar KW - hillslope sediment transport Y1 - 2018 U6 - https://doi.org/10.1029/2017JF004453 SN - 2169-9003 SN - 2169-9011 VL - 123 IS - 12 SP - 3269 EP - 3291 PB - American Geophysical Union CY - Washington ER -