Articles | Volume 9, issue 3
Short communication 23 Jun 2021
Short communication | 23 Jun 2021
Short communication: Runout of rock avalanches limited by basal friction but controlled by fragmentation
Øystein T. Haug et al.
No articles found.
Catherine Reid, John Begg, Vasiliki Mouslopoulou, Onno Oncken, Andrew Nicol, and Sofia-Katerina Kufner
Earth Surf. Dynam., 8, 351–366,
Zhiyuan Ge, Matthias Rosenau, Michael Warsitzka, and Rob L. Gawthorpe
Solid Earth, 10, 1283–1300,Short summary
Salt basins are important as they bear abundant natural resources and record valuable geological information. However, some models of salt basin evolution do not fully reconcile with natural examples. Using state-of-the-art analogue modelling, we investigate how a relatively stable area, the translational domain, occurs and gets overprinted in salt basins. The results suggest that that variation of sediment deposition is the key factor for overprinting the translational domain.
Vasiliki Mouslopoulou, John Begg, Alexander Fülling, Daniel Moraetis, Panagiotis Partsinevelos, and Onno Oncken
Earth Surf. Dynam., 5, 511–527,Short summary
A double coastal alluvial fan system on Crete is used as a proxy for landscape evolution. Each juxtaposed fan records individual phases of alluvial and marine incision, providing unprecedented resolution in the formation and evolution of its landscape. The fan sequence developed during MIS 3 due to sea-level fluctuations but it was preserved due to tectonic uplift during the subsequent 20 000 years. Thus, eustasy and tectonics were important in fan evolution, but over distinct time intervals.
Matthias Rosenau, Fabio Corbi, and Stephane Dominguez
Solid Earth, 8, 597–635,Short summary
This paper reviews experimental analogue modelling approaches to earthquakes and seismic cycles on timescales from seconds (rupture dynamics) to millions of years (tectonics). Over the last century experiments developed from simple spring-slider and fault block models to seismotectonic scale models. Based on recent advances in material characterization and monitoring techniques, analogue models today are able to simulate the seismotectonic evolution of the earth in various tectonic settings.
C. M. Krawczyk, M.-L. Buddensiek, O. Oncken, and N. Kukowski
Solid Earth, 4, 93–104,
Related subject area
Physical: Geomorphology (including all aspects of fluvial, coastal, aeolian, hillslope and glacial geomorphology)Rarefied particle motions on hillslopes – Part 1: TheoryRarefied particle motions on hillslopes – Part 2: AnalysisRarefied particle motions on hillslopes – Part 3: EntropyRarefied particle motions on hillslopes – Part 4: PhilosophyImplications of the ongoing rock uplift in NW Himalayan interiorsInteractions between deforestation, landscape rejuvenation, and shallow landslides in the North Tanganyika–Kivu rift region, AfricaRelevance of acoustic methods to quantify bedload transport and bedform dynamics in a large sandy-gravel-bed riverEarthquake-induced debris flows at Popocatépetl Volcano, MexicoControls on the hydraulic geometry of alluvial channels: bank stability to gravitational failure, the critical-flow hypothesis, and conservation of mass and energyEffect of stress history on sediment transport and channel adjustment in graded gravel-bed riversHack distributions of rill networks and nonlinear slope length–soil loss relationshipsDevelopment of smart boulders to monitor mass movements via the Internet of Things: a pilot study in NepalLaboratory observations on meltwater meandering rivulets on iceQuantifying thresholds of barrier geomorphic change in a cross-shore sediment-partitioning modelThe enigma of relict large sorted stone stripes in the tropical Ethiopian HighlandsGrowing topography due to contrasting rock types in a tectonically dead landscapeControls on the grain size distribution of landslides in Taiwan: the inﬂuence of drop height, scar depth and bedrock strengthHow do modeling choices and erosion zone locations impact the representation of connectivity and the dynamics of suspended sediments in a multi-source soil erosion model?Bedrock River Erosion through Dipping Layered Rocks: Quantifying Erodibility through Kinematic Wave SpeedParticle energy partitioning and transverse diffusion during rarefied travel on an experimental hillslopeDifferent coastal marsh sites reflect similar topographic conditions under which bare patches and vegetation recovery occurStochastic alluvial fan and terrace formation triggered by a high-magnitude Holocene landslide in the Klados Gorge, CreteCoupling threshold theory and satellite-derived channel width to estimate the formative discharge of Himalayan foreland riversInertial drag and lift forces for coarse grains on rough alluvial beds measured using in-grain accelerometersGERALDINE (Google Earth Engine supRaglAciaL Debris INput dEtector): a new tool for identifying and monitoring supraglacial landslide inputsShort communication: Multiscalar roughness length decomposition in fluvial systems using a transform-roughness correlation (TRC) approachEvolution of events before and after the 17 June 2017 rock avalanche at Karrat Fjord, West Greenland – a multidisciplinary approach to detecting and locating unstable rock slopes in a remote Arctic areaComplementing scale experiments of rivers and estuaries with numerically modelled hydrodynamicsTop-down and bottom-up controls on mountain-hopping erosion: insights from detrital 10Be and river profile analysis in Central GuatemalaCharacterization of morphological units in a small, forested stream using close-range remotely piloted aircraft imageryControls on the rates and products of particle attrition by bed-load collisionsTopographic controls on divide migration, stream capture, and diversification in riverine lifeIce sheet and palaeoclimate controls on drainage network evolution: an example from Dogger Bank, North SeaExperimental study of sediment supply control on step formation, evolution, and stabilityThe effects of topography and soil properties on radiocesium concentrations in forest soils in Fukushima, JapanA bed load transport equation based on the spatial distribution of shear stress – Oak Creek revisitedMorphometric properties of alternate bars and water discharge: a laboratory investigationTiming of exotic, far-traveled boulder emplacement and paleo-outburst flooding in the central HimalayasA 6-year lidar survey reveals enhanced rockwall retreat and modified rockfall magnitudes/frequencies in deglaciating cirquesShort communication: Field data reveal that the transport probability of clasts in Peruvian and Swiss streams mainly depends on the sorting of the grainsAlluvial cover on bedrock channels: applicability of existing modelsScale breaks of suspended sediment rating in large rivers in Germany induced by organic matterModelling impacts of spatially variable erosion drivers on suspended sediment dynamicsMātauranga Māori in geomorphology: existing frameworks, case studies, and recommendations for incorporating Indigenous knowledge in Earth scienceThe impact of earthquakes on orogen-scale exhumationQuantifying sediment mass redistribution from joint time-lapse gravimetry and photogrammetry surveysParameterization of river incision models requires accounting for environmental heterogeneity: insights from the tropical AndesMeasuring river planform changes from remotely sensed data – a Monte Carlo approach to assessing the impact of spatially variable errorEntrainment and suspension of sand and gravelMorphological evolution of bifurcations in tide-influenced deltas
David Jon Furbish, Joshua J. Roering, Tyler H. Doane, Danica L. Roth, Sarah G. W. Williams, and Angel M. Abbott
Earth Surf. Dynam., 9, 539–576,Short summary
Sediment particles skitter down steep hillslopes on Earth and Mars. Particles gain speed in going downhill but are slowed down and sometimes stop due to collisions with the rough surface. The likelihood of stopping depends on the energetics of speeding up (heating) versus slowing down (cooling). Statistical physics predicts that particle travel distances are described by a generalized Pareto distribution whose form varies with the Kirkby number – the ratio of heating to cooling.
David Jon Furbish, Sarah G. W. Williams, Danica L. Roth, Tyler H. Doane, and Joshua J. Roering
Earth Surf. Dynam., 9, 577–613,Short summary
The generalized Pareto distribution of particle travel distances on steep hillslopes, as described in a companion paper (Furbish et al., 2021a), is entirely consistent with measurements of travel distances obtained from laboratory and field-based experiments, supplemented with high-speed imaging and audio recordings that highlight the effects of bumpety-bump particle motions. Particle size and shape, in concert with surface roughness, strongly influence particle energetics and deposition.
David Jon Furbish, Sarah G. W. Williams, and Tyler H. Doane
Earth Surf. Dynam., 9, 615–628,Short summary
The generalized Pareto distribution of particle travel distances on steep hillslopes, as described in two companion papers (Furbish et al., 2021a, 2021b), is a maximum entropy distribution. This simply represents the most probable way that a great number of particles become distributed into distance states, subject to a fixed total energetic cost due to frictional effects of particle–surface collisions. The maximum entropy criterion is equivalent to a formal application of Occam's razor.
David Jon Furbish and Tyler H. Doane
Earth Surf. Dynam., 9, 629–664,Short summary
Using analyses of particle motions on steep hillslopes in three companion papers (Furbish et al., 2021a, 2021b, 2021c), we offer philosophical perspective on the merits of a statistical mechanics framework for describing sediment particle motions and transport, and the implications of rarefied versus continuum transport conditions. We highlight the mechanistic yet probabilistic nature of the approach, and the importance of tailoring the style of thinking to the process and scale of interest.
Saptarshi Dey, Rasmus C. Thiede, Arindam Biswas, Naveen Chauhan, Pritha Chakravarti, and Vikrant Jain
Earth Surf. Dynam., 9, 463–485,Short summary
Ongoing deformation of the Himalaya is not constrained to its southern extremity. With morphometric analysis using a high-resolution digital elevation model, satellite image analysis, luminescence chronology of fluvial terraces and field observations, we identify a zone of rapid rock uplift in the interior of the Kashmir Himalaya. Our results suggest active tectonic and structural control on the growth of topography in the Himalayan interiors over multi-millennial timescales.
Arthur Depicker, Gerard Govers, Liesbet Jacobs, Benjamin Campforts, Judith Uwihirwe, and Olivier Dewitte
Earth Surf. Dynam., 9, 445–462,Short summary
We investigated how shallow landslide occurrence is impacted by deforestation and rifting in the North Tanganyika–Kivu rift region (Africa). We developed a new approach to calculate landslide erosion rates based on an inventory compiled in biased © Google Earth imagery. We find that deforestation increases landslide erosion by a factor of 2–8 and for a period of roughly 15 years. However, the exact impact of deforestation depends on the geomorphic context of the landscape (rejuvenated/relict).
Jules Le Guern, Stéphane Rodrigues, Thomas Geay, Sébastien Zanker, Alexandre Hauet, Pablo Tassi, Nicolas Claude, Philippe Jugé, Antoine Duperray, and Louis Vervynck
Earth Surf. Dynam., 9, 423–444,Short summary
Despite the inherent difficulties in quantifying its value, sediment transport is essential to understanding fluvial systems. This study tries to improve the measurement by comparing several methods. Acoustic methods are compared to direct measurements with samplers. The hydrophone is well adapted to quantify sediment transport in mountain streams, but this study shows the potential and the efficiency of this device in large lowland rivers.
Velio Coviello, Lucia Capra, Gianluca Norini, Norma Dávila, Dolors Ferrés, Víctor Hugo Márquez-Ramírez, and Eduard Pico
Earth Surf. Dynam., 9, 393–412,Short summary
The Puebla–Morelos earthquake (19 September 2017) was the most damaging event in central Mexico since 1985. The seismic shaking produced hundreds of shallow landslides on the slopes of Popocatépetl Volcano. The larger landslides transformed into large debris flows that travelled for kilometers. We describe this exceptional mass wasting cascade and its predisposing factors, which have important implications for both the evolution of the volcanic edifice and hazard assessment.
Jon D. Pelletier
Earth Surf. Dynam., 9, 379–391,Short summary
The sizes and shapes of alluvial channels vary in a systematic way with the water flow they convey during large floods. It is demonstrated that the depth of alluvial channels is controlled by the resistance of channel bank material to slumping, which in turn is controlled by clay content. Deeper channels have faster water flow in a manner controlled by the critical hydraulic state to which channels tend to evolve. Channel width and slope can be further quantified using conservation principles.
Chenge An, Marwan A. Hassan, Carles Ferrer-Boix, and Xudong Fu
Earth Surf. Dynam., 9, 333–350,Short summary
Mountain rivers are characterized by fluctuations of water flow, including both flood and inter-flood low flow. Recently, increasing attention has been paid to how inter-flood low flow affects the sediment transport in subsequent floods. Here we present a series of flume experiments. Results show that the existence of inter-flood low flow can reduce the sediment transport at the beginning of the subsequent flood. However, such an effect is gradually erased with the increase of flow intensity.
Tyler H. Doane, Jon D. Pelletier, and Mary H. Nichols
Earth Surf. Dynam., 9, 317–331,Short summary
This paper explores how the geometry of rill networks contributes to observed nonlinear relationships between soil loss and hillslope length. This work develops probability functions of geometrical quantities of the networks and then extends the theory to hydraulic variables by relying on well-known relationships. Theory is complemented by numerical modeling on numerical and natural surfaces. Results suggest that the particular arrangement of rill networks contributes to nonlinear relationships.
Benedetta Dini, Georgina L. Bennett, Aldina M. A. Franco, Michael R. Z. Whitworth, Kristen L. Cook, Andreas Senn, and John M. Reynolds
Earth Surf. Dynam., 9, 295–315,Short summary
We use long-range smart sensors connected to a network based on the Internet of Things to explore the possibility of detecting hazardous boulder movements in real time. Prior to the 2019 monsoon season we inserted the devices in 23 boulders spread over debris flow channels and a landslide in northeastern Nepal. The data obtained in this pilot study show the potential of this technology to be used in remote hazard-prone areas in future early warning systems.
Roberto Fernández and Gary Parker
Earth Surf. Dynam., 9, 253–269,Short summary
We present a set of observations from laboratory experiments on meltwater meandering rivulets on ice and compare them (qualitatively and quantitatively) to patterns commonly found in meandering channels flowing over different materials. Our channels display great similarities with real rivers in spite of being much smaller. Higher temperature differences between water and ice create deeper and less sinuous channels with bends that preferentially point downstream and are not as rounded.
Daniel J. Ciarletta, Jennifer L. Miselis, Justin L. Shawler, and Christopher J. Hein
Earth Surf. Dynam., 9, 183–203,Short summary
The world's sandy coastlines are increasingly altered by humans and sea-level rise, yet quantitative relationships between coastal landscapes and sediment availability remain poorly described. Using a novel modeling framework, we explore the evolution of coastal barrier islands under varying rates of sea-level rise and sediment availability. Our model results suggest that as sea levels increase, minor changes in sediment availability could result in rapid changes to barrier coasts.
Alexander R. Groos, Janik Niederhauser, Luise Wraase, Falk Hänsel, Thomas Nauss, Naki Akçar, and Heinz Veit
Earth Surf. Dynam., 9, 145–166,Short summary
Large sorted stone stripes have been discovered on the 4000 m high central Sanetti Plateau of the tropical Bale Mountains in Ethiopia. The stripes are a mystery as similar landforms have so far only been reported in the temperate zone and polar regions. Our investigations suggest that the stripes formed in the vicinity of a former ice cap on the plateau during a much colder climatic period. The distinct pattern is the result of a process related to cyclic freezing and thawing of the ground.
Daniel Peifer, Cristina Persano, Martin D. Hurst, Paul Bishop, and Derek Fabel
Earth Surf. Dynam., 9, 167–181,Short summary
Plate tectonics drive the formation of mountain ranges. Yet when tectonic forces cease, mountain ranges persist for hundreds of millions of years, forming major Earth surface features. This work presents denudation rate estimates from one such ancient mountain range that show that denudation is strongly tied to rock type. Resistant rocks denude more slowly despite having much steeper topography, and contrasts in rock type cause increasing relief in the absence of active tectonics.
Odin Marc, Jens M. Turowski, and Patrick Meunier
Earth Surf. Dynam. Discuss.,
Revised manuscript under review for ESurfShort summary
The size of rock fragments delivered to river is essential to understand erosion and sediment transport and their related hazards. In mountains landslides deliver these rock fragments, but few studies have analyzed which properties of the landslides controlled the resulting sizes. Here we present measurement on 17 landslides from Taiwan and show that their grain sizes depend on rock-strength, landslide depth and its drop height, thus validating and updating a previous theory on fragmentation.
Magdalena Uber, Guillaume Nord, Cédric Legout, and Luis Cea
Earth Surf. Dynam., 9, 123–144,Short summary
Understanding soil erosion and suspended sediment transport is an important issue in terms of soil and water resources management. This study analyzes the impact of choices made during numerical model setup on the modeled suspended sediment dynamics at the outlet of two mesoscale watersheds. While the modeled liquid and solid discharges were found to be sensitive to these choices, the actual location of sediment sources in each catchment was the most important feature.
Nate A. Mitchell and Brian J. Yanites
Earth Surf. Dynam. Discuss.,
Revised manuscript accepted for ESurfShort summary
A landscape's appearance reflects the properties of the underlying bedrock. For example, strong bedrock can lead to steep slopes. Recent work has shown, however, that in areas with mixed rock types the stronger bedrock can have lower slopes. In this study, we use numerical models of bedrock river erosion to show why this change in behavior occurs. We also present a new approach for estimating bedrock erodibility. This new approach can allow for new opportunities in the field of geomorphology.
Sarah G. W. Williams and David J. Furbish
Earth Surf. Dynam. Discuss.,
Revised manuscript accepted for ESurf
Chen Wang, Lennert Schepers, Matthew L. Kirwan, Enrica Belluco, Andrea D'Alpaos, Qiao Wang, Shoujing Yin, and Stijn Temmerman
Earth Surf. Dynam., 9, 71–88,Short summary
Coastal marshes are valuable natural habitats with normally dense vegetation. The presence of bare patches is a symptom of habitat degradation. We found that the occurrence of bare patches and regrowth of vegetation is related to spatial variations in soil surface elevation and to the distance and connectivity to tidal creeks. These relations are similar in three marshes at very different geographical locations. Our results may help nature managers to conserve and restore coastal marshes.
Elena T. Bruni, Richard F. Ott, Vincenzo Picotti, Negar Haghipour, Karl W. Wegmann, and Sean F. Gallen
Earth Surf. Dynam. Discuss.,
Revised manuscript accepted for ESurfShort summary
The Klados River catchment contains seemingly overlarge, well-preserved, alluvial terraces and fans. Unlike previous studies, we argue that the deposits formed in the Holocene based on their relative position to a paleoshoreline uplifted in AD365 and seven radiocarbon dates. Besides, we find that constant sediment supply from high-lying landslide deposits disconnected the valley from regional tectonics and climate controls, which resulted in fan and terrace formation guided by stochastic events.
Kumar Gaurav, François Métivier, A V Sreejith, Rajiv Sinha, Amit Kumar, and Sampat Kumar Tandon
Earth Surf. Dynam., 9, 47–70,Short summary
This study demonstrates an innovative methodology to estimate the formative discharge of alluvial rivers from remote sensing images. We have developed an automated algorithm in Python 3 to extract the width of a river channel from satellite images. Finally, this channel width is translated into discharge using a semi-empirical regime equation developed from field measurements and threshold channel theory that explains the first-order geometry of alluvial channels.
Georgios Maniatis, Trevor Hoey, Rebecca Hodge, Dieter Rickenmann, and Alexandre Badoux
Earth Surf. Dynam., 8, 1067–1099,Short summary
One of the most interesting problems in geomorphology concerns the conditions that mobilise sediments grains in rivers. Newly developed
smartpebbles allow for the measurement of those conditions directly if a suitable framework for analysis is followed. This paper connects such a framework with the physics used to described sediment motion and presents a series of laboratory and field smart-pebble deployments. Those quantify how grain shape affects the motion of coarse sediments in rivers.
William D. Smith, Stuart A. Dunning, Stephen Brough, Neil Ross, and Jon Telling
Earth Surf. Dynam., 8, 1053–1065,Short summary
Glacial landslides are difficult to detect and likely underestimated due to rapid covering or dispersal. Without improved detection rates we cannot constrain their impact on glacial dynamics or their potential climatically driven increases in occurrence. Here we present a new open-access tool (GERALDINE) that helps a user detect 92 % of these events over the past 38 years on a global scale. We demonstrate its ability by identifying two new, large glacial landslides in the Hayes Range, Alaska.
David L. Adams and Andrea Zampiron
Earth Surf. Dynam., 8, 1039–1051,Short summary
This paper presents a novel method of estimating the relative contribution of different physical scales of river bed topography to the total roughness length, based on thalweg elevation profiles. By providing more detailed information regarding the interaction between surface topography and fluid dynamics, the proposed technique may contribute to advances in hydraulics, channel morphodynamics, and bedload transport. Also, it may provide alternatives to existing representative roughness metrics.
Kristian Svennevig, Trine Dahl-Jensen, Marie Keiding, John Peter Merryman Boncori, Tine B. Larsen, Sara Salehi, Anne Munck Solgaard, and Peter H. Voss
Earth Surf. Dynam., 8, 1021–1038,Short summary
The 17 June 2017 Karrat landslide in Greenland caused a tsunami that killed four people. We apply a multidisciplinary workflow to reconstruct a timeline of events and find that three historic landslides occurred in 2009, 2016, and 2017. We also find evidence of much older periods of landslide activity. Three newly discovered active slopes might pose a future hazard. We speculate that the trigger for the recent events is melting permafrost due to a warming climate.
Steven A. H. Weisscher, Marcio Boechat-Albernaz, Jasper R. F. W. Leuven, Wout M. Van Dijk, Yasuyuki Shimizu, and Maarten G. Kleinhans
Earth Surf. Dynam., 8, 955–972,Short summary
Accurate and continuous data collection is challenging in physical scale experiments. A novel means to augment measurements is to numerically model flow over the experimental digital elevation maps. We tested this modelling approach for one tidal and two river scale experiments and showed that modelled water depth and flow velocity closely resemble the measurements. The implication is that conducting experiments requires fewer measurements and results in flow data of better overall quality.
Gilles Y. Brocard, Jane K. Willenbring, Tristan Salles, Michael Cosca, Axel Guttiérez-Orrego, Noé Cacao-Chiquín, Sergio Morán-Ical, and Christian Teyssier
Earth Surf. Dynam. Discuss.,
Revised manuscript accepted for ESurfShort summary
The rise of a mountain affects the circulation of water, both in the atmosphere and over the land surface, thereby affecting the erosion of the land surface. We document how the rise of a mountain in Central Guatemala has affected the erosion of an older range nearby. The new range intercepts precipitation formerly delivered to the older range. Rivers response to the uplift of the new range has decreased incision across the older one. Both have reduced hillslope erosion over the old range.
Carina Helm, Marwan A. Hassan, and David Reid
Earth Surf. Dynam., 8, 913–929,Short summary
Forested, gravel-bed streams possess complex channel morphologies which are difficult to objectively characterize. This paper describes a novel technique using a remotely piloted aircraft (RPA) to characterize these systems below the forest canopy. The results demonstrate the accuracy and coverage of RPAs for objectively characterizing and classifying these systems relative to more traditional, time-consuming techniques that are generally used in these environments.
Kimberly Litwin Miller and Douglas Jerolmack
Earth Surf. Dynam. Discuss.,
Revised manuscript accepted for ESurfShort summary
We conducted experiments to investigate the mechanics of sediment attrition due to collisions with the channel bed during downstream transport. During this process, the grains become rounder and smaller, changing the overall distribution of sediment in the river. In this work we examine how material properties play a role in the breakdown of sediment due to energetic collisions as well as the fine particles that are produced when chipped off of larger grains.
Nathan J. Lyons, Pedro Val, James S. Albert, Jane K. Willenbring, and Nicole M. Gasparini
Earth Surf. Dynam., 8, 893–912,Short summary
Organisms evolve in ever-changing environments under complex process interactions. We applied a new software modelling tool to assess how changes in river course impact the evolution of riverine species. Models illustrate the climatically and tectonically forced landscape changes that can drive riverine biodiversity, especially where topographic relief is low. This research demonstrates that river course changes can contribute to the high riverine biodiversity found in real-world lowland basins.
Andy R. Emery, David M. Hodgson, Natasha L. M. Barlow, Jonathan L. Carrivick, Carol J. Cotterill, Janet C. Richardson, Ruza F. Ivanovic, and Claire L. Mellett
Earth Surf. Dynam., 8, 869–891,Short summary
During the last ice age, sea level was lower, and the North Sea was land. The margin of a large ice sheet was at Dogger Bank in the North Sea. This ice sheet formed large rivers. After the ice sheet retreated down from the high point of Dogger Bank, the rivers had no water supply and dried out. Increased precipitation during the 15 000 years of land exposure at Dogger Bank formed a new drainage network. This study shows how glaciation and climate changes can control how drainage networks evolve.
Matteo Saletti and Marwan A. Hassan
Earth Surf. Dynam., 8, 855–868,Short summary
Mountain streams often display a stepped morphology but the conditions under which these steps form, remain stable, and eventually collapse are still not entirely clear. We run flume experiments to study how (a) the amount of sediment input and (b) channel width variations affect step dynamics in steep channels. Steps form preferentially in areas of flow convergence (channel narrowing) and their frequency is higher when sediment supply is larger than zero but smaller than the transport capacity.
Misa Yasumiishi, Taku Nishimura, Jared Aldstadt, Sean J. Bennett, and Thomas Bittner
Earth Surf. Dynam. Discuss.,
Preprint under review for ESurfShort summary
This study demonstrates a method that analyzes radioactive contamination in forest soils, incorporating topographic parameters in the analysis. Soil samples were collected in Fukushima, Japan, where a nuclear accident had contaminated the land in 2011. The degrees to which topographic parameters explain contamination levels were calculated using a flexible regression model. This study's findings contribute to further understanding of the behavior of a radioactive contaminant in forests.
Angel Monsalve, Catalina Segura, Nicole Hucke, and Scott Katz
Earth Surf. Dynam., 8, 825–839,Short summary
Part of the inaccuracies when estimating bed load transport in gravel-bed rivers is because we are not considering the wide distributions of shear stress in these systems. We modified a subsurface-based bed load transport equation to include these distributions. By doing so, our approach accurately predicts bed load transport rates when the pavement layer is still present, while the original one predicts zero transport. For high flows, our method had similar performance to the original equation.
Marco Redolfi, Matilde Welber, Mattia Carlin, Marco Tubino, and Walter Bertoldi
Earth Surf. Dynam., 8, 789–808,Short summary
Alternate bars are large sediment deposits that tend to naturally form in rivers when the channel width is sufficiently large. Our laboratory experiments on a scaled model reveal that equilibrium properties of self-formed alternate bars highly depend on the water discharge with respect to the relevant theoretical thresholds. This work provides fundamental information for predicting the response of rivers to natural or human alterations of the flow regime.
Marius L. Huber, Maarten Lupker, Sean F. Gallen, Marcus Christl, and Ananta P. Gajurel
Earth Surf. Dynam., 8, 769–787,Short summary
Large boulders found in two Himalayan valleys show signs of long fluvial transport (>10 km). Paleo-discharges required to mobilize these boulders exceed typical monsoon discharges. Exposure dating shows that a cluster of these boulders was emplaced ca. 5 kyr ago. This period is coeval with a weakening of the Indian monsoon and glacier retreat in the area. We, therefore, suggest that glacier lake outburst floods are likely mechanisms that can explain these exceptional transport processes.
Ingo Hartmeyer, Markus Keuschnig, Robert Delleske, Michael Krautblatter, Andreas Lang, Lothar Schrott, Günther Prasicek, and Jan-Christoph Otto
Earth Surf. Dynam., 8, 753–768,Short summary
Rockfall size and frequency in two deglaciating cirques in the Central Alps, Austria, is analysed based on 6-year rockwall monitoring with terrestrial lidar (2011–2017). The erosion rates derived from this dataset are very high due to a frequent occurrence of large rockfalls in freshly deglaciated areas. The results obtained are important for rockfall hazard assessments, as, in rockwalls affected by glacier retreat, historical rockfall patterns are not good predictors of future events.
Fritz Schlunegger, Romain Delunel, and Philippos Garefalakis
Earth Surf. Dynam., 8, 717–728,Short summary
We calculated the probability of sediment transport in coarse-grained mountainous streams in the Alps and the Andes where data on water discharge is available. We find a positive correlation between the predicted probability of sediment transport and the grain size sorting of the bed material. We suggest that besides sediment discharge, the bedload sorting exerts a significant influence on the mobility of sediment and thus on the stability of gravel bars in mountainous streams.
Jagriti Mishra and Takuya Inoue
Earth Surf. Dynam., 8, 695–716,Short summary
This study provides an extensive review of field- and laboratory-scale studies and mathematical models used for predicting the sediment processes in bedrock river channels. We tested the model capabilities by reproducing and comparing the results with laboratory-scale experiments. This study provides an insight into the strengths and shortcomings of various available models.
Thomas O. Hoffmann, Yannik Baulig, Helmut Fischer, and Jan Blöthe
Earth Surf. Dynam., 8, 661–678,Short summary
We study the dynamics of suspended matter and associated nutrients in large rivers in Germany. The relationship between suspended sediment concentration and discharge is diagnostic of the processes and sources of suspended matter. We show that suspended matter originates from organic growth within the river at low flow and from soil erosion at high flow. In a warmer climate with increased frequency of droughts, low flow states are likely to be more prolonged, affecting the behavior of rivers.
Giulia Battista, Peter Molnar, and Paolo Burlando
Earth Surf. Dynam., 8, 619–635,Short summary
Suspended sediment load in rivers is highly uncertain because of spatial and temporal variability. By means of a hydrology and suspended sediment transport model, we investigated the effect of spatial variability in precipitation and surface erodibility on catchment sediment fluxes in a mesoscale river basin. We found that sediment load depends on the spatial variability in erosion drivers, as this affects erosion rates and the location and connectivity to the channel of the erosion areas.
Clare Wilkinson, Daniel C. H. Hikuroa, Angus H. Macfarlane, and Matthew W. Hughes
Earth Surf. Dynam., 8, 595–618,Short summary
This review highlights potential contributions that Indigenous knowledge can make to geomorphic research. We evaluate several frameworks and models for including Indigenous knowledge in geomorphic research and discuss how they can be adapted for use with Indigenous communities across the world. We propose that weaving Indigenous knowledge with geomorphic science has the potential to create new solutions and understandings that neither body of knowledge could produce in isolation.
Oliver R. Francis, Tristram C. Hales, Daniel E. J. Hobley, Xuanmei Fan, Alexander J. Horton, Gianvito Scaringi, and Runqiu Huang
Earth Surf. Dynam., 8, 579–593,Short summary
Large earthquakes can build mountains by uplifting bedrock, but they also erode them by triggering large volumes of coseismic landsliding. Using a zero-dimensional numerical model, we identify that the storage of sediment produced by earthquakes can affect surface uplift and exhumation rates across the mountain range. However, the storage also reduces the time span at which the impact of the earthquake can be measured, preventing the recognition of single earthquakes in many long-term records.
Maxime Mouyen, Philippe Steer, Kuo-Jen Chang, Nicolas Le Moigne, Cheinway Hwang, Wen-Chi Hsieh, Louise Jeandet, Laurent Longuevergne, Ching-Chung Cheng, Jean-Paul Boy, and Frédéric Masson
Earth Surf. Dynam., 8, 555–577,Short summary
Land erosion creates sediment particles that are redistributed from mountains to oceans through climatic, tectonic and human activities, but measuring the mass of redistributed sediment is difficult. Here we describe a new method combining gravity and photogrammetry measurements, which make it possible to weigh the mass of sediment redistributed by a landslide and a river in Taiwan from 2015 to 2017. Trying this method in other regions will help us to better understand the erosion process.
Benjamin Campforts, Veerle Vanacker, Frédéric Herman, Matthias Vanmaercke, Wolfgang Schwanghart, Gustavo E. Tenorio, Patrick Willems, and Gerard Govers
Earth Surf. Dynam., 8, 447–470,Short summary
In this contribution, we explore the spatial determinants of bedrock river incision in the tropical Andes. The model results illustrate the problem of confounding between climatic and lithological variables, such as rock strength. Incorporating rock strength explicitly into river incision models strongly improves the explanatory power of all tested models and enables us to clarify the role of rainfall variability in controlling river incision rates.
Timothée Jautzy, Pierre-Alexis Herrault, Valentin Chardon, Laurent Schmitt, and Gilles Rixhon
Earth Surf. Dynam., 8, 471–484,Short summary
Remote sensing is widely used to document historical fluvial dynamics. However, the geometric error affecting the inferred planform changes can result in undesired geomorphological misinterpretation. Here, we present a novel approach to quantify the uncertainty associated with eroded/deposited surfaces. Concluding that this uncertainty depends on the magnitude and the shape of the surficial changes, restoration programs targeting lateral mobility of streams can benefit from our approach.
Jan de Leeuw, Michael P. Lamb, Gary Parker, Andrew J. Moodie, Daniel Haught, Jeremy G. Venditti, and Jeffrey A. Nittrouer
Earth Surf. Dynam., 8, 485–504,
Arya P. Iwantoro, Maarten van der Vegt, and Maarten G. Kleinhans
Earth Surf. Dynam., 8, 413–429,Short summary
We investigated the effect of tides on the morphodynamic evolution of bifurcations in tide-influenced deltas. Using results from a numerical morphodynamic model (Delft3D), we found that tides cause less asymmetric bifurcations and thereby keep both downstream channels open. Our results explain why avulsion rarely occurs in tide-influenced deltas, whereas it occurs more often in river-dominated deltas.
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The runout of rock avalanches scales with their volume but also shows a considerable variation for avalanches with similar volumes. Here we show that besides size-dependent weakening mechanisms, fragmentation can account for the observed variability in runout. We use laboratory-scale experimental avalanches to simulate and analyse the role of fragmentation. We find that fragmentation consumes energy but also increases avalanche mobility. It does so systematically and predictably.
The runout of rock avalanches scales with their volume but also shows a considerable variation...