GeomorphologyPub Date : 2024-10-22DOI: 10.1016/j.geomorph.2024.109454
Joshua M. Williams , Louis A. Scuderi , Paul D. Zimmer , Horton E. Newsom
{"title":"Evaluating possible glacial modification in the Martian tropics near Gale crater using a new U-shaped valley metric","authors":"Joshua M. Williams , Louis A. Scuderi , Paul D. Zimmer , 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}
GeomorphologyPub Date : 2024-10-21DOI: 10.1016/j.geomorph.2024.109462
P.L.M. de Vet , B.C. van Prooijen , P.M.J. Herman , T.J. Bouma , D.S. van Maren , B. Walles , J.J. van der Werf , T. Ysebaert , E. van Zanten , Z.B. Wang
{"title":"Response of estuarine morphology to storm surge barriers, closure dams and sea level rise","authors":"P.L.M. de Vet , B.C. van Prooijen , P.M.J. Herman , T.J. Bouma , D.S. van Maren , B. Walles , J.J. van der Werf , T. Ysebaert , E. van Zanten , 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}
GeomorphologyPub Date : 2024-10-21DOI: 10.1016/j.geomorph.2024.109464
Yongsheng Zhou , Wei Wu , Jianwei Feng , Guangxu Wang , Aihua Fu , Shiqin Liang , Lulu Wu , Qingchao Li , Weiqing Liu , Zhendong Feng , Changsong Lin , Panpan Chen , Jing Yu
{"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 , Wei Wu , Jianwei Feng , Guangxu Wang , Aihua Fu , Shiqin Liang , Lulu Wu , Qingchao Li , Weiqing Liu , Zhendong Feng , Changsong Lin , Panpan Chen , 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}
GeomorphologyPub Date : 2024-10-21DOI: 10.1016/j.geomorph.2024.109470
A. Johannot, A. Recking
{"title":"Hydraulic geometry of Alpine streams channels","authors":"A. Johannot, 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<sub>c</sub>* ≈ 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<sub>1.5</sub> associated with the condition τ*/τ<sub>c</sub>* ≈ 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}
GeomorphologyPub Date : 2024-10-20DOI: 10.1016/j.geomorph.2024.109463
Yuhao Gao , Yifan Zhu , Junxi Chen , Yiting Huang , Yangbo He , Zhengchao Tian , Lirong Lin , Chongfa Cai , Jiazhou Chen
{"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 , Yifan Zhu , Junxi Chen , Yiting Huang , Yangbo He , Zhengchao Tian , Lirong Lin , Chongfa Cai , 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 < 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><sub><em>A</em></sub>). 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><sub><em>o</em></sub>), 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}
GeomorphologyPub Date : 2024-10-18DOI: 10.1016/j.geomorph.2024.109442
Jordan F. Fields , Carl E. Renshaw , Evan N. Dethier , Francis J. Magilligan
{"title":"The longer arc of channel recovery post-dam removal","authors":"Jordan F. Fields , Carl E. Renshaw , Evan N. Dethier , 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}
GeomorphologyPub Date : 2024-10-17DOI: 10.1016/j.geomorph.2024.109461
Yue Li , Yougui Song , Xinzhou Li , Xiaoxun Xie , Dimitris G. Kaskaoutis , Jovid Aminov , Sodiqjon Yatimov
{"title":"Aeolian dust dynamics in southern Central Asia revealed by the multi-timescale loess records in southern Tajikistan","authors":"Yue Li , Yougui Song , Xinzhou Li , Xiaoxun Xie , Dimitris G. Kaskaoutis , Jovid Aminov , 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}
GeomorphologyPub Date : 2024-10-17DOI: 10.1016/j.geomorph.2024.109459
Arved C. Schwendel , David J. Milan , Richard J.J. Pope , Richard Williams , Warren Thompson
{"title":"Using geophysical subsurface data for the reconstruction of valley-scale spatio-temporal floodplain evolution: Implications for upland river restoration","authors":"Arved C. Schwendel , David J. Milan , Richard J.J. Pope , Richard Williams , Warren Thompson","doi":"10.1016/j.geomorph.2024.109459","DOIUrl":"10.1016/j.geomorph.2024.109459","url":null,"abstract":"<div><div>The use of analogues of previous river styles is highly significant for successful river restoration, yet some existing techniques available to assist practitioners are still not widely applied. We explore the use of Ground Penetrating Radar (GPR), to explore past river styles in an upland river valley in the UK, and explore the potential of the approach to reconstruct former channel pattern. Post-glacial evolution of upland floodplains has been influenced by temporal changes in vegetation, sediment supply and hydrological regime. Channel-floodplain morphodynamics over the Holocene were conditioned by glacial deposits, lateral interaction with slope processes and fluvial sediment reworking, changes in flow and sediment supply regimes driven by climatic change, and more recently direct and indirect anthropogenic activities, e.g. deforestation, floodplain land use and channel modification. Current drives towards river restoration often use floodplain topography as a guide to appraise such a planform state, however, reconstruction of former channel state is often restricted to surface features visible on historic maps and aerial photographs. This research focuses upon the floodplain of the upper Swindale Beck, Lake District, UK, which was recently restored to a planform design based on the recent meander pattern visible in floodplain topography. We show the potential of GPR to reconstruct a wider array of past channel pattern and evolution at a site characterised by largely aggradational conditions and consistent sediment supply from glacial deposits at the valley head. Analysis of GPR data from 40 intersecting GPR survey lines revealed several stratigraphic units, including gravel braidplains, berms, chutes and bars, several levels of larger channels and their layered fill as well as backwater deposits. These were interpreted as braided systems, dynamic wandering planform and single-thread meandering systems with spatial transitions conditioned by tributaries and valley slope. Optically Stimulated Luminescence (OSL) dates in combination with GIS analysis of valley slope, channel gradient and local valley floor aspect allowed the interpretation of individual evolutionary stages of river and floodplain development at Swindale over at least the last millennium and provides links to processes in the wider environment including the role of alluvial fans in supplying sediment and forcing channel migration. Such information can be particularly valuable for restoration projects to aid design of channel dimensions, planform configuration, channel gradient, substrate characteristics and connection with tributaries. While restoration generally aims to resemble a more natural reference state, specific targets may seek to improve a particular set of functionalities (e.g., ecological, flood and sediment management, recreational) which should be resilient to the consequences of ongoing climatic changes and should be achieved sustainably (e.g. locally so","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"466 ","pages":"Article 109459"},"PeriodicalIF":3.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531682","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}
GeomorphologyPub Date : 2024-10-16DOI: 10.1016/j.geomorph.2024.109458
Yiming Liu , Zhiping Wu , Qizhen Du , Mingwei Wang
{"title":"Late Eocene tectonic-geomorphic transition and its dynamic mechanism: Case study of the Beibuwan Basin, northern South China Sea","authors":"Yiming Liu , Zhiping Wu , Qizhen Du , Mingwei Wang","doi":"10.1016/j.geomorph.2024.109458","DOIUrl":"10.1016/j.geomorph.2024.109458","url":null,"abstract":"<div><div>The continuous sedimentary records of the Beibuwan Basin preserve vital information on the interaction between Tethys and Pacific tectonic domains. The elusive interaction between the lithosphere and mantle significantly impacts the differential evolution of basins. However, the understanding of surface-mantle dynamic coupling beneath the Beibuwan Basin remains unclear. In this study, we analyze Cenozoic tectonic deformation, sedimentation, and mantle dynamic processes in the Beibuwan Basin in the northern South China Sea to clarify the nature of the tectonic-geomorphic transition during the late Eocene. Results show that the basin underwent late Eocene stratigraphic flexural folding, syn-rift transition from NE to EW orientated, and depocenter migration. The orientation of the primary controlling fault system during this period changed from NE-SW to NEE-SWW, the number of syn-depositional faults decreased from 368 to 172. The thickness of depocenters decreased from 5000 m to 1800 m, and the lacustrine Beibuwan Basin became shallower and wider. A comparison of the tectonic-structural history of the Beibuwan Basin with the history of plate subduction reconstructed from global geodynamic models shows that the late Eocene tectonic transition was closely related to changes in the stress field and the mantle wind related to oceanic plate subduction. We conclude that this enduring surface-mantle interaction associated with subduction of the Izanagi-Pacific mid-ocean ridge resulted in the late Eocene tectonic transition and geomorphic changes in the Beibuwan Basin.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109458"},"PeriodicalIF":3.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529710","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}
GeomorphologyPub Date : 2024-10-16DOI: 10.1016/j.geomorph.2024.109456
Edyta Kalińska , Piotr Weckwerth , Kristaps Lamsters , Helena Alexanderson , Joanna Martewicz , Alar Rosentau
{"title":"Paleostorm redeposition and post-glacial coastal chronology in the eastern Baltic Sea, Latvia","authors":"Edyta Kalińska , Piotr Weckwerth , Kristaps Lamsters , Helena Alexanderson , Joanna Martewicz , Alar Rosentau","doi":"10.1016/j.geomorph.2024.109456","DOIUrl":"10.1016/j.geomorph.2024.109456","url":null,"abstract":"<div><div>The 494 km long Latvian coast consists of sandy sediments, which serve as an excellent proxy for past coastal events and environment. Our study explores these understudied sediments along the western coast of the Gulf of Riga and combines two sand quartz-wise methods: optically stimulated luminescence (OSL) dating and grain microtextures. We provide a new chronology and microsedimentary results to trace post-glacial storm events and discuss correlations within the Baltic Sea region and elsewhere in Europe. OSL ages reveal a wide time span between 10.38 ± 0.61 ka and 1.04 ± 0.05 ka BP, but their inconsistency in the profiles along with the onshore position of landforms and gravelly horizons argues for sediment relocation due to storm action. A first paleostorm phase is dated to between 7.6 ± 1.2 ka and 4.63 ± 0.27 ka, corresponding with a transgression of the Littorina Sea and the Holocene Thermal Maximum, and with a roughly estimated vertical sediment redeposition above 5 m similar with the recent storms in the region. Sedimentary record from microstudy supports intense storm activity, especially in sediments redeposited after 6.07 ± 0.51 ka, and it is seen through an increased number of cracked quartz grains, shiny grains and fresh surfaces combined with a limited number of V-shaped marks. Weaker storm action, recorded by a lower share of cracked grains in the sediments, occurred between 7.6 ± 1.2 ka and 6.07 ± 0.51 ka.</div><div>A second storm phase occurred at 1.44 ± 0.21 ka, corresponding with the post-Littorina, again with a performance of a weaker storm. Apart from the palaeostorm records, the beach ridges developed between 5.16 ± 0.33 ka and 4.47 ± 0.31 ka along with drier conditions when aeolian deposition took place twice: at 4.63 ± 0.27 ka and 1.55 ± 0.10 ka.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"467 ","pages":"Article 109456"},"PeriodicalIF":3.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529101","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}