scholarly journals Downvalley fining of hillslope sediment in an alpine catchment: implications for downstream fining of sediment flux in mountain rivers

2020 ◽  
Vol 45 (8) ◽  
pp. 1828-1845 ◽  
Author(s):  
Leonard S. Sklar ◽  
Clifford S. Riebe ◽  
Jennifer Genetti ◽  
Shirin Leclere ◽  
Claire E. Lukens
Keyword(s):  
Sediment Flux ◽  
Mountain Rivers ◽  
Downstream Fining

SOME REGULARITIES OF CHANNEL FORMATION IN THE UPPER COURSE OF MOUNTAIN RIVERS (BAKSAN RIVER AS AN EXAMPLE)

2015 ◽  
pp. 49 ◽  
Author(s):  
N. N. Vinogradova ◽  
I. V. Krylenko ◽  
V. V. Sourkov
Keyword(s):  
Channel Formation ◽  
Mountain Rivers

Sediment Flux and Trapping on the Skagit Tidal Flats: Analysis and Modeling

2010 ◽  
Author(s):  
David K. Ralston ◽  
W. R. Geyer ◽  
Peter Traykovski
Keyword(s):  
Tidal Flats ◽  
Sediment Flux

Sediment Flux to the Coastal Zone: Predictions for the Navy

2001 ◽  
Author(s):  
James P. Syvitski ◽  
Charles J. Vorosmarty
Keyword(s):  
Coastal Zone ◽  
Sediment Flux

Geoinformation Mapping Through the Types of Geological and Geomorphological Structure of the Katun Valley (Altay Mountains) Based on Morphometric Indicators

2018 ◽  
Vol 938 (8) ◽  
pp. 38-43
Author(s):  
S.A. Kotler ◽  
I.D. Zolnikov ◽  
D.V. Pchelnikov
Keyword(s):  
Morphometric Parameters ◽  
Morphometric Parameter ◽  
Geological History ◽  
Mountain Rivers ◽  
Quaternary Period ◽  
Modern Variety ◽  
Altay Mountains ◽  
History Of

The types of geological and geomorphological structure of the Katun valley are distinguished in the work. For this, a method of geoinformation mapping using morphometric indicators of the valley’s width and meandering of the channel was developed. The morphometric parameter of the valley’s width was calculated as the total area of terraces. As the morphometric parameters of the channel’s meandering, the angles of the river segments’ deviation relative to each other were calculated. Conjugated analysis of these morphometric indicators enabled identifying 18 morphotypes. These morphotypes according to the geological and geomorphological structure of the valley were combined into 4 classes. Separation of the Katun valley in certain classes and morphotypes is due to the different geological history of these sites during the Quaternary period. The most important reasons predetermining the modern variety of geological and geomorphological types of the valley are neotectonic movements and exogenous phenomena (glaciers, dam lakes, landslides, etc.) naturally localized in the space from the upstream of the river to its exit into the foothills. The developed method can be applied for quantitative morphometric classification of the mountain rivers’ valleys in other regions.

HIGH-SEDIMENTATION EVENTS AND ANNUAL SEDIMENT FLUX IN A SEDIMENT TRAP RECORD FROM LINNÉVATNET, SVALBARD

2017 ◽  
Author(s):  
Noel L. Potter ◽  
◽  
Michael J. Retelle
Keyword(s):  
Sediment Trap ◽  
Sediment Flux ◽  
High Sedimentation ◽  
Annual Sediment

ANTHROPOGENIC IMPACTS ON SEDIMENT FLUX TO THE OCEAN

2019 ◽  
Author(s):  
Peter D. Clift ◽  
Keyword(s):  
Anthropogenic Impacts ◽  
Sediment Flux

scholarly journals The role of sulphur on the melting of Ca-poor sediment and on trace element transfer in subduction zones: an experimental investigation

2021 ◽  
Author(s):  
Anne-Aziliz Pelleter ◽  
Gaëlle Prouteau ◽  
Bruno Scaillet
Keyword(s):  
Trace Element ◽  
Partial Melting ◽  
Subduction Zones ◽  
Sediment Flux ◽  
Arc Magmas ◽  
Trace Element Contents ◽  
The Stability ◽  
Element Transfer ◽  
High Sediment

Abstract We performed phase equilibrium experiments on a natural Ca-poor pelite at 3 GPa, 750-1000 °C, under moderately oxidizing conditions, simulating the partial melting of such lithologies in subduction zones. Experiments investigated the effect of sulphur addition on phase equilibria and compositions, with S contents of up to ∼ 2.2 wt. %. Run products were characterized for their major and trace element contents, in order to shed light on the role of sulphur on the trace element patterns of melts produced by partial melting of oceanic Ca-poor sediments. Results show that sulphur addition leads to the replacement of phengite by biotite along with the progressive consumption of garnet, which is replaced by an orthopyroxene-kyanite assemblage at the highest sulphur content investigated. All Fe-Mg silicate phases produced with sulphur, including melt, have higher MgO/(MgO+FeO) ratios (relative to S-free/poor conditions), owing to Fe being primarily locked up by sulphide in the investigated redox range. Secular infiltration of the mantle wedge by such MgO and K2O-rich melts may have contributed to the Mg and K-rich character of the modern continental crust. Addition of sulphur does not affect significantly the stability of the main accessory phases controlling the behaviour of trace elements (monazite, rutile and zircon), although our results suggest that monazite solubility is sensitive to S content at the conditions investigated. The low temperature (∼ 800 °C) S-bearing and Ca-poor sediment sourced slab melts show Th and La abundances, Th/La systematics and HFSE signatures in agreement with the characteristics of sediment-rich arc magmas. Because high S contents diminish phengite and garnet stabilities, S-rich and Ca-poor sediment sourced slab melts have higher contents of Rb, B, Li (to a lesser extent), and HREE. The highest ratios of La/Yb are observed in sulphur-poor runs (with a high proportion of garnet, which retains HREE) and beyond the monazite out curve (which retains LREE). Sulphides appear to be relatively Pb-poor and impart high Pb/Ce ratio to coexisting melts, even at high S content. Overall, our results show that Phanerozoic arc magmas from high sediment flux margins owe their geochemical signature to the subduction of terrigenous, sometimes S-rich, sediments. In contrast, subduction of such lithologies during Archean appears unlikely or unrecorded.

scholarly journals Insights on the Impacts of Hydroclimatic Extremes and Anthropogenic Activities on Sediment Yield of a River Basin

Earth ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 32-50
Author(s):  
Rocky Talchabhadel ◽  
Jeeban Panthi ◽  
Sanjib Sharma ◽  
Ganesh R. Ghimire ◽  
Rupesh Baniya ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
River Basin ◽  
Extreme Precipitation ◽  
Suspended Sediment Concentration ◽  
Anthropogenic Activities ◽  
Sediment Concentration ◽  
Sediment Flux ◽  
Mountain River ◽  
Ecological Processes ◽  
Precipitation Indices

Streamflow and sediment flux variations in a mountain river basin directly affect the downstream biodiversity and ecological processes. Precipitation is expected to be one of the main drivers of these variations in the Himalayas. However, such relations have not been explored for the mountain river basin, Nepal. This paper explores the variation in streamflow and sediment flux from 2006 to 2019 in central Nepal’s Kali Gandaki River basin and correlates them to precipitation indices computed from 77 stations across the basin. Nine precipitation indices and four other ratio-based indices are used for comparison. Percentage contributions of maximum 1-day, consecutive 3-day, 5-day and 7-day precipitation to the annual precipitation provide information on the severity of precipitation extremeness. We found that maximum suspended sediment concentration had a significant positive correlation with the maximum consecutive 3-day precipitation. In contrast, average suspended sediment concentration had significant positive correlations with all ratio-based precipitation indices. The existing sediment erosion trend, driven by the amount, intensity, and frequency of extreme precipitation, demands urgency in sediment source management on the Nepal Himalaya’s mountain slopes. The increment in extreme sediment transports partially resulted from anthropogenic interventions, especially landslides triggered by poorly-constructed roads, and the changing nature of extreme precipitation driven by climate variability.

scholarly journals Contrasting lipid biomarkers in mountain rivers in the Nepal Himalayas: Organic matter characteristics and contribution to the fluvial carbon pool

2021 ◽  
pp. 101231
Author(s):  
Rajendra Bhandari ◽  
Joyanto Routh ◽  
Subodh Sharma ◽  
Rajendra Joshi
Keyword(s):  
Organic Matter ◽  
Carbon Pool ◽  
Lipid Biomarkers ◽  
Mountain Rivers
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