The quintessential s-shape in sedimentology: A review on the formation and controls of clinoform shape DOI Creative Commons
Ingrid Anell

Earth-Science Reviews, Journal Year: 2024, Volume and Issue: 254, P. 104821 - 104821

Published: May 25, 2024

Clinoforms are ubiquitous depositional surfaces in sedimentary systems. The quintessential shape, with a flat or gentle topset, sloping foreset, and to bottomset, is recognizable the smallest ripple kilometer high edges of continents. Essentially shape one which develops differential sedimentation away from source. Systematic decay transport competence and/or sediment amount site favouring deposition, generates loading typically lens-shaped body. lithology, grain size, water depth, hydrodynamic factors, mechanisms, antecedent topography, relative sea level rate all interact create different sizes, slopes shapes. Meanwhile there several fundamental similarities between clinoforms, even bedwave features (ripples dunes), despite forming under very conditions. All clinoforms some extent governed by accommodation energy limiting factors (water agitation flow regime), controls their height, proxy influences slope angle. Lithology exerts control, can build angle repose, higher for coarser non-cohesive sediment, while cohesive gentler slopes, also fail at lower angles. Sediment repose steep linear segments, but conversely on continental margins extremely low angle, probably reflecting little along-slope contrast mud-dominance. clinothems similar lithology display wide range foreset angles, indicating numerous additional controls. Sedimentation appears exert significant control steepness, limited promoting steeper related basinward thinning deposits. observation greater depth response deepening environments generating effect comparatively less sedimentation. Processes important controlling as tidal wave reworking, debris flows, overpressure failure, Turbidity currents meanwhile part dynamic system both steepen slope. There four basic clinoform shapes: concave, linear, convex, sigmoidal. These develop variations along profile driven erosion/bypass/factors deposition/accumulation/waning supply. Curvature tends be an indication contrast, such erosional sandier muddier Sigmoidal clinothems, associated more trajectories, shorter than concave clinothems. Decaying shear-zone reworking erosion shapes rounded rollover. carrying capacity ensuing curvature. Concave lacking topsets sharp rollovers often longer sigmoidal forms. Their formation likely closely linked increased accumulation through bypass, turbidity currents, suspension-dominated deposition smaller clinoforms. In this ripples differ, transition rounding crest, unlike larger

Language: Английский

Mega-reservoir regulation: A comparative study on downstream responses of the Yangtze and Yellow rivers DOI
Xiao Wu, Yao Yue, Alistair G.L. Borthwick

et al.

Earth-Science Reviews, Journal Year: 2023, Volume and Issue: 245, P. 104567 - 104567

Published: Sept. 14, 2023

Language: Английский

Citations

28
Hidden delta degradation due to fluvial sediment decline and intensified marine storms DOI Creative Commons
Qingguang Zhu, Fei Xing, Ya Ping Wang

et al.

Science Advances, Journal Year: 2024, Volume and Issue: 10(18)

Published: May 3, 2024

Deltas are threatened by erosion due to climate change and reduced sediment supply, but their response these changes remains poorly quantified. We investigate the abandoned Yellow River delta that has transitioned from rapid growth ongoing deterioration a river avulsion removing supply. Integrating bathymetric data, process observations, transport modeling, we find while subaerial was stabilized engineering measures, subaqueous continued erode intensified storms, losing 39% of its mass deposited before avulsion. Long-term observations show winter storms initiate scouring delta, contributing up 70% seabed erosion. then analyze 108 global deltas assess risks identify 17 facing similar situations decline storm intensification during past 40 years. Our findings suggest must be integrated into sustainability evaluations.

Language: Английский

Citations

9
Cascading Erosion in the Tide‐Dominated Changjiang Delta: A Novel Radionuclide Approach DOI Creative Commons
Yijing Wu, Daidu Fan, Jianfeng Su

et al.

Geophysical Research Letters, Journal Year: 2025, Volume and Issue: 52(4)

Published: Feb. 22, 2025

Abstract Nearshore erosion is well‐documented in sediment‐deficit river deltas but remains less understood beyond their delta front (DF), particularly its extension to the deeper prodelta (PD) and distal mud (DM). This study investigates response of Changjiang subaqueous DM sediment decline following 2003 closure Three Gorges Dam. By analyzing temporal spatial variations 210 Pb ex profile styles, discrepancies between 137 Cs accumulation rates, surface grain sizes, we identified onset at DF shortly after 2003, which spread PD by 2009 reached northern 2015. tracking burial depths 1963 peak, found progressively lower rates newly eroded subzones primarily due redistribution. study, leveraging historical radionuclides data, offers a valuable approach for monitoring areas lacking remote sensing detection bathymetric data.

Language: Английский

Citations

1
The coming perfect storm: Diminishing sustainability of coastal human–natural systems in the Anthropocene DOI Creative Commons
John W. Day, Charles A. S. Hall,

Kent Klitgaard

et al.

Cambridge Prisms Coastal Futures, Journal Year: 2023, Volume and Issue: 1

Published: Jan. 1, 2023

Abstract We review impacts of climate change, energy scarcity, and economic frameworks on sustainability natural human systems in coastal zones, areas high biodiversity, productivity, population density, activity. More than 50% the global lives within 200 km a coast, mostly tropical developing countries. These developed during stable Holocene conditions. Changes forcings are threatening ecosystems populations. During Holocene, earth warmed became wetter more productive. Climate changes impacting via sea level rise, stronger cyclones, basin inputs, extreme weather events. passing tipping points as fossil fuel-powered industrial-technological-agricultural revolution has overwhelmed source–sink functions biosphere degraded systems. The current status industrialized society is primarily result fuel (FF) use. FFs provided 80% primary projected to decline by mid-century. This profound implications for societal requirements, including transition renewable economy. development industrial economy allowed social become spatially separated from their dominant food sources. will difficult maintain with fading cheap energy. It seems inevitable that past growth use, resource consumption, cannot be sustained, forefront these challenges. Rapid planning cooperation necessary minimize associated coming transition. There an urgent need new framework guide through mainstream neoclassical economics not based sciences does adequately consider either importance or work nature.

Language: Английский

Citations

23
Coastal Wetlands in the Anthropocene DOI Open Access

John W. Day,

Edward J. Anthony, Robert Costanza

et al.

Annual Review of Environment and Resources, Journal Year: 2024, Volume and Issue: 49(1), P. 105 - 135

Published: Sept. 4, 2024

We review the functioning and sustainability of coastal marshes mangroves. Urbanized humans have a 7,000-year-old enduring relationship to wetlands. Wetlands include marshes, salt flats, saline freshwater forests. Coastal wetlands occur in all climate zones but are most abundant deltas. Mangroves tropical, whereas from tropical boreal areas. Quantification wetland areas has advanced recent years is still insufficiently accurate. Climate change sea-level rise predicted lead significant losses other impacts on associated with them. Landward migration retreat not expected significantly reduce losses. Nitrogen watershed inputs unlikely alter marsh stability because loadings mostly lower than those fertilization studies that show decreased belowground biomass increased decomposition soil organic matter. Blue carbon impacts. The high values ecosystem goods services be reduced by area Humans had strong Holocene, these increase Anthropocene.

Language: Английский

Citations

7
Delta sustainability from the Holocene to the Anthropocene and envisioning the future DOI
Edward J. Anthony,

Jaia Syvitski,

Florin Zăinescu

et al.

Nature Sustainability, Journal Year: 2024, Volume and Issue: 7(10), P. 1235 - 1246

Published: Oct. 9, 2024

Language: Английский

Citations

7
Data, knowledge, and modeling challenges for science-informed management of river deltas DOI Creative Commons
Rafael Schmitt, Philip S. J. Minderhoud

One Earth, Journal Year: 2023, Volume and Issue: 6(3), P. 216 - 235

Published: March 1, 2023

Language: Английский

Citations

15
Economic Development Drives Massive Global Estuarine Loss in the Anthropocene DOI Creative Commons
Nathalie W. Jung, Guan‐hong Lee, Timothy M. Dellapenna

et al.

Earth s Future, Journal Year: 2024, Volume and Issue: 12(4)

Published: April 1, 2024

Abstract Estuaries have great ecological and economic value sustain both population growth. Global‐scale analyses suggest that human activities drive estuarine area change but these projections neglect direct human‐estuary interactions socio‐economic feedbacks. Here, we quantified changes of 2,396 estuaries in response to recent impacts (e.g., land reclamation, dam construction) development between 1984 2019, find shrank by 5,372 km 2 whereas upland submergence created 5,015 elsewhere. Approximately 44% ( n = 1,046) today's been directly altered through construction, or a combination both, ∼250,000 acres (1,027 ) converted urban agricultural fields. Nearly 90% (923 reclamation occurred Asia linked advances during the middle‐income stage. Additional historical mapping 5‐year interval revealed while alterations were insignificant low‐income stages, predominantly their where degradation is common consequence However, this trend stabilizes high‐income countries with adaption conservation laws policies. Together, our results indicate large‐scale loss can be avoided preserving low‐ mid‐income early stages development.

Language: Английский

Citations

6
Post-glacial small delta process uncovered by luminescence and radiocarbon chronology of core sediments from coastal South China Sea DOI
Yuexin Liu, Guanjun Xu,

Gui Long

et al.

Quaternary Geochronology, Journal Year: 2024, Volume and Issue: 82, P. 101530 - 101530

Published: April 25, 2024

Language: Английский

Citations

6
Future flooding of the Volta Delta caused by sea level rise and land subsidence DOI
Emmanuel K. Brempong, Rafaël Almar, Donatus Bapentire Angnuureng

et al.

Journal of Coastal Conservation, Journal Year: 2023, Volume and Issue: 27(3)

Published: June 1, 2023

Language: Английский

Citations

13