Geomorphology最新文献

{"title":"Glacial cirque identification based on Convolutional Neural Networks","authors":"Dongxue Mao ,&nbsp;Yingkui Li ,&nbsp;Qiang Liu ,&nbsp;Iestyn D. Barr ,&nbsp;Ian S. Evans","doi":"10.1016/j.geomorph.2024.109472","DOIUrl":"10.1016/j.geomorph.2024.109472","url":null,"abstract":"<div><div>Cirques provide important information about the palaeoclimate conditions that produced past glaciers. However, mapping cirques is challenging, time-consuming, and subjective due to their fuzzy boundaries. A recent study tested the potential of using a deep learning algorithm, Convolutional Neural Networks (CNN), to predict boundary boxes containing cirques. Based on a similar CNN method, RetinaNet, we use a dataset of &gt;8000 cirques worldwide and various combinations of digital elevation models and their derivatives to detect these features. We also incorporate the Convolutional Block Attention Module (CBAM) into RetinaNet for training and prediction. The precision of cirque detection with or without the addition of the CBAM is evaluated for various input data combinations, and training sample sizes, based on comparison with mapped cirques in two test areas on the Kamchatka Peninsula and the Gangdise Mountains. The results show that the addition of CBAM increases the average precision by 4–5 % (<em>p</em> &lt; 0.01), and the trained model can detect the cirque boundary boxes with high precision (84.7 % and 87.0 %), recall (94.7 % and 86.6 %), and <em>F</em>_<em>1</em> score (0.89 and 0.87), for the two test areas, respectively. The inclusion of CBAM also significantly reduces the number of undetected cirques. The model performance is affected by the quantity and quality of the training samples: the performance generally increases with increasing training samples and a training dataset of 6000 cirques produces the best results. This trained model can effectively detect boundary boxes that contain cirques to help facilitate subsequent cirque outline extraction and morphological analysis.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109472"},"PeriodicalIF":3.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537224","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":"Understanding sediment and carbon accumulation in macrotidal minerogenic saltmarshes for climate resilience","authors":"Amann Benjamin ,&nbsp;Chaumillon Eric ,&nbsp;Bertin Xavier ,&nbsp;Pignon-Mussaud Cécilia ,&nbsp;Marie-Claire Perello ,&nbsp;Christine Dupuy ,&nbsp;Long Nathalie ,&nbsp;Schmidt Sabine","doi":"10.1016/j.geomorph.2024.109465","DOIUrl":"10.1016/j.geomorph.2024.109465","url":null,"abstract":"<div><div>Coastal saltmarshes play an essential role in providing services such as sediment and carbon storage, coastal protection and support for biodiversity. Despite their importance, understanding the factors controlling sediment and carbon accumulation in these minerogenic saltmarshes remains challenging due to their diversity and site-specific characteristics. Understanding the respective role of these drivers is essential for effective coastal management, particularly for mitigating the impacts of climate change. This study evaluates the control of forcing factors on the lateral and vertical morphological evolution and carbon burial rates of three minerogenic saltmarshes located on the French Atlantic coast (Pertuis Charentais region). By focusing on these sites, the study isolates specific factors such as wind and wave exposure, inundation frequency, and sediment availability, while minimizing confounding influences like climate and tidal range. Results reveal significant lateral expansion of saltmarsh boundaries towards the sea across all sites, with the highest rates of progradation observed in the protected areas influenced by geomorphological features such as sand spits and sheltered bay heads. Sediment and mass accumulation rates (SAR; MAR), derived from ²¹⁰Pb and ¹³⁷Cs profiles of sediment cores (<em>n</em> = 14), range from 0.48 to 2.22 cm yr⁻¹, among the highest reported globally, with notable variability within and between sites. Inundation frequency and accommodation space explain SAR variability within sites, while sediment availability predominantly determines spatial differences in vertical accumulation rates between sites. Organic carbon burial rates range from 75 to 345 gC m⁻² yr⁻¹, and show a strong correlation with SAR (<em>r</em> = 0.9, <em>p</em> <em>&lt;</em> 0.001, <em>n</em> = 13) but no dependence on carbon content or density (<em>r</em> = 0.2, <em>p</em> <em>&gt;</em> 0.05, n = 13). This highlights the role of sediment input in the accumulation and sequestration of carbon by minerogenic saltmarshes. Furthermore, isotopic analysis indicates a marine source dominance in organic carbon sediment. This research provides insights into how different environmental conditions affect saltmarsh morphological evolution and carbon sequestration rates, informing targeted coastal management strategies focused on enhancing ecosystem resilience and climate resilience.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109465"},"PeriodicalIF":3.1,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552654","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":"Constraining the origin of the Norwegian strandflat – The influence of isostatic and dynamic surface changes","authors":"Cecilia E. Nielsen ,&nbsp;Jane L. Andersen ,&nbsp;Annina Margreth ,&nbsp;Ola Fredin ,&nbsp;Vivi K. Pedersen","doi":"10.1016/j.geomorph.2024.109484","DOIUrl":"10.1016/j.geomorph.2024.109484","url":null,"abstract":"<div><div>The Norwegian strandflat is a prominent low-relief bedrock surface found near sea level along most of the west coast of Norway. Its origin has been discussed throughout the last 130 years but is yet to be resolved. Some studies suggest that the strandflat represent a tropical weathering front of Mesozoic age that has since been buried and re-exhumed, while others relate its origin to Pleistocene periglacial and glacial processes and/or wave-induced weathering and erosion. Previous interpretations of the strandflat have considered postglacial isostatic uplift, but the impacts of isostatic changes due to glacial erosion and deposition, as well as dynamic surface changes driven by mantle convection, have been largely overlooked. Here we examine how geomorphological-driven isostatic changes and dynamic surface changes have influenced the land-surface elevation along the Norwegian coast during late Pliocene-Quaternary (the last ca. 3 million years). We employ quantitative estimates of glacial erosion and deposition to assess the flexural isostatic response from the resulting load changes. Our analyses show that patterns of geomorphic isostatic adjustments and dynamic surface changes are generally not reflected in the present elevation of the strandflat. Only the loading effect from the deposition of the North Sea Fan can clearly be correlated with the submerged strandflat found near Stad (∼62 °N). Our results imply that if the strandflat formed synchronously along the Norwegian coast as a flat surface at sea level, the strandflat we observe today must have developed after the majority of late Pliocene-Quaternary glacial erosion took place, but prior to the main deposition of the North Sea Fan. This would place strandflat formation within the last few glacial cycles, but before the Last Glacial Maximum (LGM). This inferred pre-LGM age of the strandflat is generally consistent with cosmogenic nuclide exposure ages and observed striations on the strandflat. Finally, we examine ice cover and land-surface changes relative to sea level during the last 80,000 years and find no extended periods favorable for synchronous strandflat formation across all regions along the Norwegian coast. This implies that either the strandflat is diachronous, or that the processes of formation have either been extremely fast under certain conditions or are independent of sea level, for instance related to glacial erosion.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109484"},"PeriodicalIF":3.1,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553197","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":"Evaluating possible glacial modification in the Martian tropics near Gale crater using a new U-shaped valley metric","authors":"Joshua M. Williams ,&nbsp;Louis A. Scuderi ,&nbsp;Paul D. Zimmer ,&nbsp;Horton E. Newsom","doi":"10.1016/j.geomorph.2024.109454","DOIUrl":"10.1016/j.geomorph.2024.109454","url":null,"abstract":"<div><div>Growing evidence supports the case for glacial processes within the equatorial regions of Mars. However, few examples of modeling or numerical analysis exist to support this hypothesis. Here we apply an automated method on valleys near Gale crater to extract morphometric data and analyze formative processes responsible for their current expression. The V-index utilized is a new robust method that is an alternative to traditional valley parabolic curve fits. This approach more easily characterizes irregular valley cross sections and thus aids in distinguishing between glacial and nonglacial forms. We applied this method along with standard power law and quadratic curve fits on valley cross sections along a 2300 km extent of the Martian tropics near Gale crater. Both V-index and power law b fit values suggest that the majority of the valleys are U-shaped and possibly created through glacial erosive processes. Further, V-index and power law b values plotted against elevation show a positive trend with higher V-index (glaciated) values associated with higher elevation. This suggests that an equilibrium-line altitude (ELA) may have existed at the time of valley formation. The timing of the formation of these U-shaped valleys is poorly defined. However, our initial crater statistics conducted within the study area suggest a young ∼1.05 (±0.25) Ga relative ages of the valley floors. Equatorial glaciers that produced these and other related glacial forms may be as old as the Hesperian to Amazonian transition (∼3 Ga) but more intriguingly may be associated with Amazonian equatorward migration of the Martian cryosphere during more recent periods of high obliquity oscillations.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109454"},"PeriodicalIF":3.1,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529703","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":"Response of estuarine morphology to storm surge barriers, closure dams and sea level rise","authors":"P.L.M. de Vet ,&nbsp;B.C. van Prooijen ,&nbsp;P.M.J. Herman ,&nbsp;T.J. Bouma ,&nbsp;D.S. van Maren ,&nbsp;B. Walles ,&nbsp;J.J. van der Werf ,&nbsp;T. Ysebaert ,&nbsp;E. van Zanten ,&nbsp;Z.B. Wang","doi":"10.1016/j.geomorph.2024.109462","DOIUrl":"10.1016/j.geomorph.2024.109462","url":null,"abstract":"<div><div>Storm surge barriers and closure dams influence estuarine morphology. Minimizing consequential ecological impacts requires a thorough understanding of the morphological adaptation mechanisms and associated time scales. Both are unraveled using three decades of morphological measurements on the adaptation of the Eastern Scheldt estuary (The Netherlands) to a storm surge barrier and closure dams. Both the storm surge barrier (through a decrease in cross-sectional area) and closure dams (inducing a reduction in surface area of the estuary) contributed to a reduction in tidal prism. As a smaller tidal prism implies a smaller equilibrium volume of the channels, the channels demand sediment to adjust. Consequently, by providing sediment to the channels, the intertidal flats erode. Erosion rates decreased while the sediment demand of the channels attenuated. This attenuation in sediment demand resulted mainly from tidal prism gains, caused by intertidal flat erosion and sea level rise. Erosion rates of the intertidal flats decreased further while they flattened to adapt to the reduced tidal velocities. Furthermore, storms caused erosion events, after which the long-term adaptation pace of intertidal flats suddenly reduced. Despite decreasing erosion, sea level rise enhances the drowning of intertidal flats in sediment-scarce estuarine systems, thereby pressuring these estuarine ecosystems and raising the need for mitigation measures.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109462"},"PeriodicalIF":3.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578639","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":"Mechanism and controlling factors of mass transport complexes migration: A case study of the mass transport complexes in the taranaki deep water basin, New Zealand","authors":"Yongsheng Zhou ,&nbsp;Wei Wu ,&nbsp;Jianwei Feng ,&nbsp;Guangxu Wang ,&nbsp;Aihua Fu ,&nbsp;Shiqin Liang ,&nbsp;Lulu Wu ,&nbsp;Qingchao Li ,&nbsp;Weiqing Liu ,&nbsp;Zhendong Feng ,&nbsp;Changsong Lin ,&nbsp;Panpan Chen ,&nbsp;Jing Yu","doi":"10.1016/j.geomorph.2024.109464","DOIUrl":"10.1016/j.geomorph.2024.109464","url":null,"abstract":"<div><div>Mass transport Complexes (MTCs) form significant sediment accumulations in continental slopes, hold key insights for natural hazard prediction and offshore oil exploration. This paper uses high-definition 3D seismic data to reconstruct the seismic geomorphology and sedimentary dynamics of MTCs, meticulously exploring the depositional systems of the Tanaraki Basin, New Zealand. It deciphers by kinematic notation, seismic faciess, quantifies megaclast morphological characteristics, in conjunction with the basal slope and channel structure development as the migration or kinematics of MTCs. Five seismic facies categories and dynamic traits—compression ridges, thrust faults, slides, grooves and slope terraces are distinguished in MTCs. Based on attributes maps and geomorphological interpretations, MTCs is segmented into four zones, showing combined effects of levée, basal slopes, and megaclast clusters on its migration. Lithological and topographical variations along these features modulate erosion properties and MTCs mobility, with base height shifts guiding local migration trajectories. The results of megaclast parameters in Zones 1 and 3 tune our understanding of stress patterns and directionality shifts, highlighting the complex dynamics at play. Notably, the differential motion triggered by levees instigates longitudinal shear zones. At critical migration disparities, MTCs fracture at these weak points, discharging pore pressure and filling fractures with fines, birthing “promontory” formations marked by low-amplitude fills. This work, therefore, establishes a groundbreaking migratory model that synthesizes the impacts of levees height, rock type variability, and megaclasts accumulation intensity, depicting a fragmented migration pattern. This study not only enriches our grasp of MTCs behavior in deep-water contexts but also furnishes a robust scientific foundation and predictive tool for gauging the hazards that MTCs may pose to underwater structures, thus carrying substantial theoretical and applied significance.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109464"},"PeriodicalIF":3.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529706","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":"Hydraulic geometry of Alpine streams channels","authors":"A. Johannot,&nbsp;A. Recking","doi":"10.1016/j.geomorph.2024.109470","DOIUrl":"10.1016/j.geomorph.2024.109470","url":null,"abstract":"<div><div>This paper aims to analyze and discuss what controls the geometry of incised alpine streams. For this, we construct a dataset comprising 39 cross-sections and the associated grain size measured in 10 rivers. We then examine each geometry to discuss the definition of bankfull and the associated hydraulics. We conclude that in these incised cross section, width remains nearly constant for a wide range of discharge, including discharges as low as discharge with an exceedance probability of 0.01 (discharge exceeded 3.65 days/yr). In particular, the hydraulics associated with geometric markers located in the lower part of each cross-section suggest that Parker's theory of a threshold forming Shields stress ratio τ*/τ_c* ≈ 1.5 established at bankfull for non-incised gravel bed rivers still keep its significance within the incised section. We suggest that the width W_1.5 associated with the condition τ*/τ_c* ≈ 1.5 can be used as a reference width in alpine streams for river restoration or for risk management.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109470"},"PeriodicalIF":3.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529709","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":"Understanding the role of topography on valley floor gully and hillslope gully development in cropland of the rolling hill region of northeast China","authors":"Yuhao Gao ,&nbsp;Yifan Zhu ,&nbsp;Junxi Chen ,&nbsp;Yiting Huang ,&nbsp;Yangbo He ,&nbsp;Zhengchao Tian ,&nbsp;Lirong Lin ,&nbsp;Chongfa Cai ,&nbsp;Jiazhou Chen","doi":"10.1016/j.geomorph.2024.109463","DOIUrl":"10.1016/j.geomorph.2024.109463","url":null,"abstract":"<div><div>In regions with steep slopes, the classification of permanent gully (PG) into hillslope gullies (HG) and valley floor gullies (VG) was obvious before the study began. However, in the rolling hill region (slope &lt; 5°), the difference between HG and VG was often overlooked. Moreover, there is no standardized approach for classifying gullies, which results in ambiguity regarding the impact of topography on various developmental stages of gullies and significantly impairs the effective management of gully erosion in the rolling hill region. We propose a remote sensing-based classification method to categorize 1081 PG into VG and HG in the cropland of the rolling hill region. The high-resolution satellite images (0.7 m) from 2010 and 2021 of all PGs were used to obtain the gully development rate and distribution patterns. Among these, 79 typical PGs were investigated using UAV to acquire high-resolution DEM (5 cm), which was used to analyze the relationship between the single or composite topographic factor and gully development rates. The results show that the proposed classification method can effectively recognize the VG and HG in the rolling hill region. The average length, area, and volume of the VG were found to be 2.31, 3.15, and 6.59 times that of the HG, respectively. The rate of gully head retreat, expansion area, and volume of the VG were also 1.59, 2.48, and 5.81 times faster than that of the HG, respectively. In HG and VG, the retreat rate of gully head (Δ<em>l</em>) both showed a positive linear correlation with the distance from the gully head to the catchment divide (<em>L</em>_<em>A</em>). The extension rate of gully area (Δ<em>a</em>) was positively linearly and exponentially correlated with composite topographic factor <em>SA</em> (product of local slope (<em>S</em>) and contributing area above the gully head (<em>A</em>)). Additionally, the Δ<em>a</em> of VG was strongly related to the shape and size of <em>A</em>, while the Δ<em>a</em> of HG was strongly related to <em>S</em>. The gully volume expansion rate (Δ<em>V</em>) of both HG and VG was influenced by factors such as the existing size of the gully, the contributing area of the outlet (<em>A</em>_<em>o</em>), and the elevation difference from the outlet to the gully head (<em>h</em>). Hence, the changes in Δ<em>l</em> and Δ<em>a</em> for PG are primarily attributed to hydraulic erosion, while Δ<em>V</em> is influenced by both hydraulic and gravitational erosion. The study has shown the non-negligible influence of HG and VG in the rolling hill region. And the composite topographic factors can also better predict the PG development rate. This study contributes to the formulation of effective soil erosion prevention strategies and sustainable land management practices.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109463"},"PeriodicalIF":3.1,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529705","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 longer arc of channel recovery post-dam removal","authors":"Jordan F. Fields ,&nbsp;Carl E. Renshaw ,&nbsp;Evan N. Dethier ,&nbsp;Francis J. Magilligan","doi":"10.1016/j.geomorph.2024.109442","DOIUrl":"10.1016/j.geomorph.2024.109442","url":null,"abstract":"<div><div>Dam removals are opportunistic experiments to address fundamental questions about river recovery to disturbance. Previous studies have shown that gravel-bedded rivers are resilient with covariate adjustments to channel dimensions occurring rapidly in the wake of disturbance. Yet, beyond the cross section, at the reach or watershed-scale, adjustment appears to take much longer. Understanding of the longer arc of reach and watershed recovery is limited by the relatively few dam removals studies that include long-term monitoring. Here, we present results from a five-year dam removal study punctuated by an extreme flood and show that the initial, rapid response of a channel is driven by the prevailing hydrology whereas longer-term adjustments to morphology at the reach scale are driven by external forces imposed on the channel. We summarize these results by classifying various channel features as either ‘intrinsic channel properties’ that are rapidly adjustable by the prevailing hydrology or ‘extrinsic channel properties’ that respond over various time scales to external boundary conditions imposed on the channel by climate, vegetation, geology, and valley dimensions (extrinsic controls). We show that this framework applies to channel recovery beyond the former reservoir and thus may prove applicable to channel disturbances beyond dam removal, such as extreme floods.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"468 ","pages":"Article 109442"},"PeriodicalIF":3.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662704","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":"Aeolian dust dynamics in southern Central Asia revealed by the multi-timescale loess records in southern Tajikistan","authors":"Yue Li ,&nbsp;Yougui Song ,&nbsp;Xinzhou Li ,&nbsp;Xiaoxun Xie ,&nbsp;Dimitris G. Kaskaoutis ,&nbsp;Jovid Aminov ,&nbsp;Sodiqjon Yatimov","doi":"10.1016/j.geomorph.2024.109461","DOIUrl":"10.1016/j.geomorph.2024.109461","url":null,"abstract":"<div><div>Dust activity in Central Asia (CA) holds significant scientific interest due to their broad social and environmental impacts. Loess deposits in CA serve as crucial natural archives, recording regional atmospheric characteristics and dust dynamics. The oldest loess in CA has been discovered in southern Tajikistan. However, debates persist regarding the wind dynamics of the Tajikistan loess deposition, which motivates our current study. By analyzing grain sizes of the last glacial loess and previous loess records since 800 ka, we determined that the Tajikistan loess consisted of post-storm floating dust and fine-grained dust transported by the westerlies. The reduced grain sizes may indicate less frequent dust storms. Our results provided explanation for the influence of global ice volume changes on the dust dynamics in southern Tajikistan, primarily by modulating sea-level pressure differences between the Caspian Sea and Hindu Kush/Pamirs. These ice volume changes also intensified rapid atmospheric fluctuations in CA, suggesting a sensitive response of the latter to glacial boundary conditions. Moreover, although precipitation variations may influence dust activities, their impact appears to be minimal. Collectively, our findings offer vital insights into the formation of loess strata and the development of extensive modern loess landforms in southern CA.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109461"},"PeriodicalIF":3.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529712","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}