Geomorphology最新文献

{"title":"Evaluation of geodiversity in the Brazilian Amazon using different quantification methodologies","authors":"Julio Manoel França da Silva ,&nbsp;Juliana de Paula Silva ,&nbsp;Fernando César Manosso","doi":"10.1016/j.geomorph.2024.109441","DOIUrl":"10.1016/j.geomorph.2024.109441","url":null,"abstract":"<div><div>When one considers geodiversity as the variability of abiotic elements distributed on the earth's surface in an unequal and complex manner, and that the configuration of these elements plays an important role in ecosystem dynamics, it becomes necessary and important to evaluate the different forms by which its spatial organization can be quantified and mapped. A recent academic effort in different countries, scales, and territories aims to evaluate and quantify geodiversity and its spatial variation. Thus, this work aims to apply and compare the spatial distribution of the geodiversity indices derived from four methodologies in the Brazilian Amazon. From this analysis, we seek to understand the distribution of the geodiversity indices in the Brazilian Amazon and organize a cartographic base for future correlations with spatial data representative of biodiversity and human appropriation of the territory. When one considers the tendencies of spatial similarity for each methodology, regardless of the size and shape of the quantification cells, the indices generated with the second methodology have a higher correlation with the basic index. In general, since they consider the same diversity measure (richness), the tendencies of direct spatial similarity are highlighted by the basic index and the products of the second methodology. The Shannon's index in the 250 × 250 km hexagonal grids, besides the high value of positive correlation, is also equivalent to the basic index, regaining the spatial proportion of each class, above all other indices. The indices generated from Shannon's and Simpson's indices tend to differ from the other indices because, besides class richness, they also measure evenness. The comparison between the quantitative indices shows some tendencies in the spatial patterns of geodiversity of the Brazilian Amazon but also presents indications of the limitations imposed by the different measurement criteria of the abiotic variables used.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109441"},"PeriodicalIF":3.1,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulsed uplift of the South Tianshan since the Late Miocene indicated by the linear inversion on river longitudinal profiles","authors":"Jiangang Li ,&nbsp;Wentian Liang ,&nbsp;Yizhou Wang ,&nbsp;Shida Song ,&nbsp;Qi Shen ,&nbsp;Sihua Yuan","doi":"10.1016/j.geomorph.2024.109448","DOIUrl":"10.1016/j.geomorph.2024.109448","url":null,"abstract":"<div><div>The early Cenozoic collision and subsequent continuous convergence between the Indian and Eurasian plates reactivated the Tianshan orogen in the Central Asia and caused multistage uplift of the mountain range. The modern Tianshan, with high mountain peaks of &gt;7000 m, forms very prominent topography that profoundly affects the regional tectonics and climate. However, the late Cenozoic uplift process and topography growth of the South Tianshan remain controversial. River longitudinal profile inversion provides a distinctive way to reveal rock uplift history since the late Cenozoic. In this study, we presented linear inversion on river longitudinal profiles of four drainage basins originating from high mountains in the South Tianshan. The inversion results from two basins in the northern flank show fast and continuous increases in the uplift rates from about 0.1–0.2 mm/a to 0.6–1.0 mm/a since 4 Ma. While in the southern flank, the uplift rates of the two basins increased gradually from about 0.1 mm/a to 0.2 mm/a before 10 Ma and from 0.2 mm/a to 0.4 mm/a around 10 Ma and 6 Ma, respectively. Our results combined with recently published chronological data in this region indicate that the South Tianshan experienced a pulsed tectonic uplift process since the Late Miocene. Moreover, the pulsed tectonic uplift should lead to an elevated South Tianshan during 6–4 Ma, coinciding well with the ∼5.3 Ma extreme aridification in the Tarim Basin, thus supporting that the rain shadow effect caused by high topography of South Tianshan is a critical reason for aridification.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109448"},"PeriodicalIF":3.1,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geomorphic characteristics influencing post-fire river response in mountain streams","authors":"Shayla Triantafillou,&nbsp;Ellen Wohl","doi":"10.1016/j.geomorph.2024.109446","DOIUrl":"10.1016/j.geomorph.2024.109446","url":null,"abstract":"<div><div>As wildfires increase in frequency and severity, there is a growing interest in understanding river response to the wildfire disturbance cascade. Numerous headwater mountain catchments within the Cache la Poudre (Poudre) River basin in the Colorado Front Range, USA burned severely and extensively during the 2020 Cameron Peak fire. Debris flows and flash floods occurred in many of these catchments triggered by convective storms after the fire. The downstream effects of the floods and sediment varied along a continuum from attenuated and largely contained within the catchment, to releasing substantial volumes of water and sediment to the Poudre River. We conceptualize these catchments as exhibiting decreasing absorbance of post-fire disturbance along the continuum described above based on the geomorphic evidence of relative sediment export. We conceptualize characteristics on different spatial scales as driving or resisting response to disturbance and therefore impacting the absorbing capacity (ability to attenuate post-fire fluxes) of the catchment. As the magnitude of resisting characteristics increases at the catchment, inter- and intra- reach scales, we hypothesize that a catchment will increasingly absorb the impacts of the wildfire disturbance cascade. We conducted longitudinally continuous surveys to measure reach-scale characteristics within each study catchment. We focus on the catchment- and reach-scale geomorphic, vegetation, and burn characteristics. The floods observed at the study catchments illustrate fire influencing the elevation above which rainfall-induced flooding occurs due to the efficient conveyance of water from hillslopes to channels after wildfire. Results suggest that inter- and intra-reach spatial heterogeneity are better aligned with absorbance capacity than catchment-scale characteristics: greater absorbing capacity is associated with greater longitudinal variations in floodplain/channel width and more reaches with wide floodplains, low channel gradients, beaver-modified topography, and multi-stem deciduous vegetation. We connect the capacity to absorb the impacts of disturbance as informing the catchment response to wildfire disturbance.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109446"},"PeriodicalIF":3.1,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The glacial and periglacial evolution of Coprates Chasma (Valles Marineris, Mars)","authors":"Fabio Vittorio De Blasio,&nbsp;Giovanni Battista Crosta,&nbsp;Davide Fusetti,&nbsp;Elena Valbuzzi","doi":"10.1016/j.geomorph.2024.109444","DOIUrl":"10.1016/j.geomorph.2024.109444","url":null,"abstract":"<div><div>The search for past and present water on Mars, either as liquid or solid ice, with its important climatological and astrobiological consequences, has been bolstered by novel techniques, and from the release of recent imagery. Although ice is more frequently observed at higher latitudes, evidence of ice and water-related deposits and erosional features has also been identified at equatorial latitudes. This work focuses on the evidence for ancient ice and water-related features in Valles Marineris, Mars' most extensive canyon system, particularly in its deepest southeastern section, Coprates Chasma. We first consider existing information on water, glacial, and periglacial landforms and introduce new findings and imagery based on orbiters and on physical considerations.</div><div>We examine the peculiar morphologies of two major landslides in Coprates Chasma, which can potentially imply icy conditions at the chasm's base. Analogies to Earth's glacially-induced landslides could hint at similar dynamics and the presence of ice within Valles Marineris. Remarkably intact landforms in Coprates Chasma include pitted cones remnants, commonly deduced to be volcanic cinder cones or mud volcanoes, and here interpreted as landforms more similar to pingos or hydrolaccolites, and then protalus ramparts, ice-affected impact craters, kettle holes from ice melt or sublimation, alases, and rock glaciers. The fluted terrain at the forefront of the Coprates Labes landslide indicate the presence of running water at the bottom of Coprates Chasma about 3 Ga ago. A 20-km long feature, here nicknamed the “Ghost Glacier”, characterized by thin sub-parallel grooves, is interpreted as the remnant of a series of drop moraines abandoned by a local cold-based glacier, possibly one of the Valles Marineris' (Magnarini et al., 2019) oldest identifiable features. By examining the contacts between landslide deposits and the terrain of stacked landslide sequences, including craters underneath a landslide body, we deduce that ice in Valles Marineris was present as permafrost or in thin bodies growing locally to at most some meters in thickness. Moreover, the longitudinal profile indicates the lack of a thick glacier within the main valley. We conclude that the past occurrence of glacialism in Valles Marineris was only partly suggestive of glacial conditions found in Earth's Alpine valleys. Additionally, imagery corroborates the existence of a regolith-veneered lacustrine surface, dated to a recent age of 1.1 Ga, over which a massive landslide slid. We propose a tentative hydrological-glaciological history of Coprates Chasma, grounded in published research and our findings.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109444"},"PeriodicalIF":3.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleozoic-Mesozoic multistage tectonic evolution of the North Qilian Shan revealed by detrital zircon U-Pb and fission-track double dating","authors":"Xu Lin ,&nbsp;Marc Jolivet ,&nbsp;Jing Liu-Zeng ,&nbsp;Kaige Guan ,&nbsp;Feng Cheng ,&nbsp;Soares Cleber ,&nbsp;Chengwei Hu","doi":"10.1016/j.geomorph.2024.109447","DOIUrl":"10.1016/j.geomorph.2024.109447","url":null,"abstract":"<div><div>Knowledge of the tectonic history of the North Qilian Shan contributes to our understanding of the formation of the Tibetan Plateau. However, when the North Qilian Shan were formed has been controversial. We report new detrital zircon U-Pb (n = 899) and double dating fission track and U-Pb (n = 450) results from nine samples of Lower Cretaceous and Oligocene sandstone units, integrating with published geochronology and thermochronology data in order to reconstruct the evolution history of the North Qilian Shan. Nine samples from this unit show detrital zircon fission track age populations that center at: 636–603, 495, 406–331, 290–266, 247–224, 193–151, and 144–102 Ma. These fission track data are older than their corresponding depositional ages, suggesting that the fission track ages are unreset and record magmatic-related cooling or exhumation stages of the North Qilian Shan since the Late Neoproterozoic. Deconvolved fission track peak ages document major cooling events associated with the opening of the North Qilian Ocean at 636–603 Ma. Late Cambrian peak age (495 Ma) is attributed to the early phase of the subduction of the North Qilian Ocean. The Devonian period exhibited a cooling phase between 406 and 381 Ma, corresponding to the collision event between the Qaidam terrane, Central Qilian Shan, and Alxa Block. The peak age of 331 Ma signifies the cooling event associated with the subduction of the Paleo-Asian Ocean. The peak ages during the Early-Middle Permian period (290–266 Ma) provide evidence of significant exhumation events that occurred during the Late Paleozoic era. These events were linked to the subduction of the Paleo-Tethys Ocean to the south and the Paleo-Asian Ocean to the north. The Triassic peak ages (247–224 Ma) unveil exhumation signals in the North Qilian Shan region that were generated by the far-field effect of the collision between the Qiangtang and Kunlun terranes. During the Jurassic (193–151 Ma) and the Early Cretaceous periods (144–102 Ma), the exhumation of the North Qilian Shan region was a consequence of the subduction of the Neo-Tethys Ocean and the collision between the Lhasa and Qiangtang blocks, respectively. The peak ages of the Xinminpu Formation in the Early Cretaceous (123–121 Ma) are in close proximity to their depositional age (125–105 Ma), indicating that the North Qilian Shan underwent rapid exhumation during this period. The peak ages observed in the Oligocene Baiyanghe Formation (31–24 Ma) from 144 to 102 Ma, indicate that it has been influenced by the recycled sediments originating from the Cretaceous Xinminpu Formation. The North Qilian Shan gradually emerged during the late Paleozoic and Mesozoic eras, providing the foundation for its subsequent reactivation in the Cenozoic era. The multi-stage cooling or exhumation events of North Qilian Shan since Late Neoproterozoic reflect the complex formation process of the northeastern margin of Tibetan Plateau.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109447"},"PeriodicalIF":3.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bedform generation beneath shoaling nonlinear internal waves on a mild slope","authors":"A. Ghassemi,&nbsp;L. Boegman","doi":"10.1016/j.geomorph.2024.109439","DOIUrl":"10.1016/j.geomorph.2024.109439","url":null,"abstract":"<div><div>Subaqueous sand waves have been observed where nonlinear internal waves (NLIWs) shoal on continental margins. To investigate their generation mechanisms, we propagated periodic NLIWs of depression to shoal upon a sloping bed in a laboratory flume. Following fission of the incident waves, ripple-type bedforms were observed between the point of incipient suspension and interaction point (where the quiescent pycnocline intersects the sediment bed). The largest ripples were centered on the bolus birth point, where the NLIWs of elevation, generated by fission, transform into boluses and maximum near-bed velocities occurred. The ripple height and wavelength were consistent with fluvial scaling. In two experiments, where bedload transport was not predicted, the observations showed resuspension to influence ripple generation. Net upslope sediment movement was observed beyond the turning point.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109439"},"PeriodicalIF":3.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proposal of a facet-to-facet multiple flow direction algorithm based on geometrical and mathematical analysis of physical dispersion over triangle facet","authors":"Zhenya Li ,&nbsp;Xijun Lai ,&nbsp;Pengfei Shi ,&nbsp;Tao Yang","doi":"10.1016/j.geomorph.2024.109440","DOIUrl":"10.1016/j.geomorph.2024.109440","url":null,"abstract":"<div><div>Flow direction algorithms have been widely used to extract crucial terrain attributes of great hydrological and geomorphological significance. However, essential distinctions between the empirically-designed strategies of typical algorithms and the natural rules of physical dispersions bring various problems (e.g. parallel channel, artificial dispersion), leading to the low size and extent precisions of estimated results. In this work, geometrical and mathematical analysis is conducted on the inherent characteristics of physical dispersions along slope lines on local terrains. On each 3 × 3 window of digital elevation model (DEM), center pixel is divided into eight non-overlapping sub-facets. Necessary and sufficient (NS) conditions of size relationships between the elevations of adjacent pixels are summarized to directly identify the receiving facets of a sub-facet. Then, strict mathematical relations are derived between slope direction of a sub-facet and flow proportions allocated to receiving facets. A strategy is designed to re-adjust receiving facets and flow proportions for the boundary flow of adjacent facets. Lastly, a multiple-flow-direction algorithm called TFGA is proposed with the NS condition of size relationships, mathematical relation of slope direction with flow proportion, and adjustment strategy of boundary flow. Case studies are conducted for investigating the total contributing areas (TCA) and specific contributing areas (SCA) estimated by TFGA. Results reveal all-side superiorities of TFGA to typical algorithms in spatial patterns, error indicators and statistic characteristics of estimated TCAs and SCAs. Particularly, TFGA improves size precision of estimated results by approximately one order of magnitude. In a conclusion, we highly recommend TFGA for digital elevation analysis.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109440"},"PeriodicalIF":3.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flow and depositional response of turbidity currents to complex canyon topographies: A numerical simulation perspective","authors":"Yang Lu ,&nbsp;Xiaolei Liu ,&nbsp;Yuping Yang ,&nbsp;Dawei Wang ,&nbsp;Heyu Yu ,&nbsp;Shaopeng Zhang ,&nbsp;Xiaotian Xie ,&nbsp;Xingsen Guo","doi":"10.1016/j.geomorph.2024.109437","DOIUrl":"10.1016/j.geomorph.2024.109437","url":null,"abstract":"<div><div>Submarine canyons are prominent features on continental margins, acting as major conduits for sediment transport primarily through turbidity currents. Understanding how these currents interact with complex canyon topographies is crucial for deciphering the canyon system evolution, yet challenging due to limited field observations. Focusing on a group of slope-confined canyons within the Pearl River Mouth Basin, northern South China Sea, this study integrates multibeam bathymetry, core analysis, and process-based Computational Fluid Dynamics (CFD) modeling to investigate the influence of realistic canyon topography on turbidity current dynamics and resulting sediment deposition. Analysis of core samples revealed a potential turbidite layer characterized by silts and sandy silts. Using these sediment information and bathymetric data, we conducted a series of three-dimensional CFD simulations. Our findings highlight the significant variability in turbidity current characteristics, particularly flow velocity and sediment concentration, within the canyon groups. This variability is primarily controlled by canyon head depth, the width-to-relief ratio, and slope gradients. Notably, the simulations revealed unique flow structures not typically observed in experimental settings, including unidirectional flows, small-scale helical flows, stacked and mixed flow cells, and flow separation and convergence across inter-canyon ridges. Our CFD simulations also revealed a distinct near-wall pattern of linear deposition of coarse-grained sediments, which is similar to the observed bathymetric changes between 2009 and 2017. Based on the consistent results, we propose a conceptual model wherein differential erosion, driven by oceanographic processes, plays a key role in shaping the observed linear depositional patterns.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109437"},"PeriodicalIF":3.1,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring the temporal evolution of a Sicilian badland area by unmanned aerial vehicles","authors":"Vincenzo Palmeri ,&nbsp;Costanza Di Stefano ,&nbsp;Gaetano Guida ,&nbsp;Alessio Nicosia ,&nbsp;Vito Ferro","doi":"10.1016/j.geomorph.2024.109443","DOIUrl":"10.1016/j.geomorph.2024.109443","url":null,"abstract":"<div><div>Badlands are extremely fragmented landforms characterized by soil erosion processes at a short-time scale. In this paper, the annual evolution of hillslope morphological characteristics and erosion/deposition processes in a Sicilian badland area, surveyed on May 2021 and April 2022 by Unmanned Aerial Vehicles (UAVs), was investigated. Three-dimensional (3D) and planimetric (2D) approaches were applied to determine the badland morphometric characteristics. UAV surveys and photogrammetric 3D-model generation allowed for obtaining the digital terrain model and identifying the badland unit. The convergence index method was applied to evaluate the drainage network and its variation due to the erosion processes. The analysis highlighted a decrease of the morphometric indexes with increasing slope, which can be explained by the fact that the drainage network tends to be less tortuous and branched as slopes become steeper. The geomorphic change analysis showed that the soil erosion is evenly distributed along the badland slopes, while it is negligible along the drainage networks. The geomorphic changes due to slope collapses and soil erosion and deposition phenomena lead to a modification of the morphological characteristics of the badland unit, sub-units and the corresponding drainage networks. The results confirmed that badlands are intense erosion spots, with soil loss (approximately 348 t ha⁻¹ y⁻¹) much higher than the soil loss tolerance. Finally, the morphometric indexes were positively related to the sediment yield values, suggesting that in more extended and branched drainage networks sediment transport is more efficient.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109443"},"PeriodicalIF":3.1,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of coseismic bedrock landslides in the landscape evolution of high-relief mountainous terrain: Insights from detrital 10Be dilution modeling","authors":"Jiajun Peng ,&nbsp;Yuki Matsushi ,&nbsp;Hiroyuki Matsuzaki","doi":"10.1016/j.geomorph.2024.109432","DOIUrl":"10.1016/j.geomorph.2024.109432","url":null,"abstract":"<div><div>Episodic landslides supply vast quantities of debris from hillslopes to channels, resulting in the dilution of cosmogenic nuclides in fluvial sediment. This study revisited the nuclide dilution concept and proposed a novel model framework to quantify landslide-derived sediment yields to interpret the responses of entire landscape systems to tectonic forcing in an active orogen. The model was applied to datasets of detrital ¹⁰Be concentrations obtained from the Minjiang catchment in the eastern margin of the Tibetan Plateau, where the impacts of coseismic landslides were documented during the 2008 Wenchuan earthquake. Presumable model parameters were evaluated through multifaceted geospatial analyses by adopting the normalized channel steepness index as a proxy for background denudation rate, which was then converted to the corresponding nuclide concentration; the fluvial channel geometry was adopted for evaluating pre-event fluvial sediment storage. The scaling factors for quantifying the landslide debris influx were obtained via inversion of the diluted ¹⁰Be concentrations and corresponding landslide inventory to verify the feasibility of the model. The calibrated model was then applied at the regional scale to evaluate the long-term net denudation of the hillslopes with a certain earthquake recurrence interval. The resulting spatial distribution of increased denudation is consistent with very-long-term exhumation rates derived from low-temperature thermochronology, implying the critical role of coseismic landslides in mass removal from hillslopes to counterbalance long-term tectonic uplift.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109432"},"PeriodicalIF":3.1,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}