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Your search keyword '"SEDIMENT transport"' showing total 2 results
Start Over Descriptor "SEDIMENT transport" Topic geography Publisher public library of science
2 results on '"SEDIMENT transport"'

1. End-member modelling as a tool for climate reconstruction—An Eastern Mediterranean case study.

Author

Beuscher, Sarah, Krüger, Stefan, Ehrmann, Werner, Schmiedl, Gerhard, Milker, Yvonne, Arz, Helge, and Schulz, Hartmut

Subjects
*TERRIGENOUS sediments, *CLIMATE change, *PARTICLE size distribution, *CLIMATE reconstruction (Research), *SEDIMENT transport
Abstract

The Eastern Mediterranean Sea is a sink for terrigenous sediments from North Africa, Europe and Asia Minor. Its sediments therefore provide valuable information on the climate dynamics in the source areas and the associated transport processes. We present a high-resolution dataset of sediment core M40/4_SL71, which was collected SW of Crete and spans the last ca. 180 kyr. We analysed the clay mineral composition, the grain size distribution within the silt fraction, and the abundance of major and trace elements. We tested the potential of end-member modelling on these sedimentological datasets as a tool for reconstructing the climate variability in the source regions and the associated detrital input. For each dataset, we modelled three end members. All end members were assigned to a specific provenance and sedimentary process. In total, three end members were related to the Saharan dust input, and five were related to the fluvial sediment input. One end member was strongly associated with the sapropel layers. The Saharan dust end members of the grain size and clay mineral datasets generally suggest enhanced dust export into the Eastern Mediterranean Sea during the dry phases with short-term increases during Heinrich events. During the African Humid Periods, dust export was reduced but may not have completely ceased. The loading patterns of two fluvial end members show a strong relationship with the Northern Hemisphere insolation, and all fluvial end members document enhanced input during the African Humid Periods. The sapropel end member most likely reflects the fixation of redox-sensitive elements within the anoxic sapropel layers. Our results exemplify that end-member modelling is a valuable tool for interpreting extensive and multidisciplinary datasets. [ABSTRACT FROM AUTHOR]

Published
2017
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2. Continental slope and rise geomorphology seaward of the Totten Glacier, East Antarctica (112°E-122°E)

Author

Amy Leventer, German Leitchenkov, Bradley Opdyke, Philip E O'Brien, L. Holder, Federica Donda, Adrián López-Quirós, T. Martin, Alexandra L. Post, Andrea Caburlotto, Meghan Duffy, Dimitris Evangelinos, Leanne K. Armand, S. Edwards, Roberto Romeo, Australian Research Council, Ministerio de Ciencia e Innovación (España), Ministerio de Economía y Competitividad (España), López-Quiros, Adrián [0000-0002-7522-2834], and López-Quiros, Adrián

Subjects
Canyon, geography, geography.geographical_feature_category, Turbidity current, 010504 meteorology & atmospheric sciences, Continental shelf, Totten Glacier, Geology, Submarine canyon, Ridges, Hemipelagic sediment, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Thalweg, Continental margin, Geochemistry and Petrology, Submarine canyons, Antarctica, Geomorphology, Sediment transport, Continental slope and rise, 0105 earth and related environmental sciences
Abstract

The continental slope and rise seaward of the Totten Glacier and the Sabrina Coast, East Antarctica features continental margin depositional systems with high sediment input and consistent along-slope current activity. Understanding their genesis is a necessary step in interpreting the paleoenvironmental records they contain. Geomorphic mapping using a systematic multibeam survey shows variations in the roles of downslope and along slope sediment transport influenced by broad-scale topography and oceanography. The study area contains two areas with distinct geomorphology. Canyons in the eastern part of the area have concave thalwegs, are linked to the shelf edge and upper slope and show signs of erosion and deposition along their beds suggesting cycles of activity controlled by climate cycles. Ridges between these canyons are asymmetric with crests close to the west bank of adjacent canyons and are mostly formed by westward advection of fine sediment lofted from turbidity currents and deposition of hemipelagic sediment. They can be thought of as giant levee deposits. The ridges in the western part of the area have more gently sloping eastern flanks and rise to shallower depths than those in the east. The major canyon in the western part of the area is unusual in having a convex thalweg; it is likely fed predominantly by mass movement from the flanks of the adjacent ridges with less sediment input from the shelf edge. The western ridges formed by accretion of suspended sediment moving along the margin as a broad plume in response to local oceanography supplemented with detritus originating from the Totten Glacier. This contrasts with interpretations of similar ridges described from other parts of Antarctica which emphasise sediment input from canyons immediately up-current. The overall geomorphology of the Sabrina Coast slope is part of a continuum of mixed contourite-turbidite systems identified on glaciated margins., Australian Government 4333, Australian Research Council DP170100557, Italian Programma Nazionale di Richerch in Antartide (PNRA), Spanish Government CTM2014-60451-C2-1-P CTM2017-89711-C2-1-P

Published
2020
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