Depositional and Erosional Coastal Processes During the Last Postglacial Sea-Level Rise: An Example from the Central Tyrrhenian Continental Shelf (Italy)

1996 ◽  
Vol Vol. 66 ◽  
Author(s):  
Paolo Tortora
Keyword(s):  
Continental Shelf ◽  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Processes

scholarly journals Global distribution of nearshore slopes with implications for coastal retreat

2019 ◽  
Author(s):  
Panagiotis Athanasiou ◽  
Ap van Dongeren ◽  
Alessio Giardino ◽  
Michalis Vousdoukas ◽  
Sandra Gaytan-Aguilar ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Sea Level Rise ◽  
Sea Level ◽  
Large Scale ◽  
Input Parameter ◽  
Coastal Processes ◽  
The World ◽  
Important Input ◽  
Significant Spatial Variation ◽  
Coastal Retreat

Abstract. Nearshore slope, defined as the cross-shore gradient of the subaqueous profile, is an important input parameter which affects hydrodynamic and morphological coastal processes. It is used in both local and large-scale coastal investigations. However, due to unavailability of data, most studies, especially those that focus on continental or global scales, have historically adopted a uniform nearshore slope. This simplifying assumption could however have far reaching implications for predictions/projections thus obtained. Here, we present the first global dataset of nearshore slopes with a resolution of 1 km at almost 620,000 points along the global coastline. To this end, coastal profiles were constructed using global topo-bathymetric datasets. The results show that the nearshore slopes vary substantially around the world. An assessment of sea level rise (SLR) driven coastline recession (for an arbitrary 0.5 m SLR) with a globally uniform coastal slope of 1:100, as done in previous studies, and with the spatially variable coastal slopes computed herein shows that, on average, the former approach would under-estimate coastline recession by about 40 %, albeit with significant spatial variation. The final dataset has been made publicly available at https://doi.org/10.4121/uuid:a8297dcd-c34e-4e6d-bf66-9fb8913d983d.

Future Sea Level Rise and Changes on Tides in the Patagonian Continental Shelf

2015 ◽  
Vol 313 ◽  
pp. 519-535 ◽  
Author(s):  
Moira Luz Clara ◽  
Claudia G. Simionato ◽  
Enrique D'Onofrio ◽  
Diego Moreira
Keyword(s):  
Continental Shelf ◽  
Sea Level Rise ◽  
Sea Level

scholarly journals First direct evidence for a contiguous Gondwana shelf to the south of the Rheic Ocean

Geology ◽  
2019 ◽  
Vol 47 (8) ◽  
pp. 767-770 ◽  
Author(s):  
Rolf L. Romer ◽  
Uwe Kroner
Keyword(s):  
Continental Shelf ◽  
Sea Level Rise ◽  
Sea Level ◽  
Large Scale ◽  
Direct Evidence ◽  
Oceanic Lithosphere ◽  
Black Shales ◽  
Early Paleozoic ◽  
Rheic Ocean ◽  
Variscan Orogen

Abstract Sea-level rise after the Hirnantian glaciation resulted in the global inundation of continental shelf areas and the widespread formation of early Silurian black shales. Black shales that were deposited on shelves receiving drainage from earlier glaciated areas have high uranium (U) contents because large-scale glacial erosion brought rocks with leachable U to the surface. In contrast, black shales receiving drainage from non-glaciated areas that had lost leachable U earlier have low U contents. Early Silurian U-rich shales formed only on shelf areas that had not been separated from earlier-glaciated mainland Gondwana by oceanic lithosphere. Therefore, early Silurian U-rich black shales within the Variscan orogen provide direct evidence that these areas had not been separated from mainland Gondwana, but were part of the same, contiguous shelf. This implies that the Rheic Ocean was the only pre-Silurian ocean that opened during the early Paleozoic extension of the peri-Gondwana shelf.

Sea-level rise impacts on the tides of the European Shelf: mechanisms analysis

2020 ◽  
Author(s):  
Deborah Idier ◽  
François Paris ◽  
Goneri Le Cozannet ◽  
Faiza Boulahya ◽  
Franck Dumas
Keyword(s):  
Continental Shelf ◽  
Sea Level Rise ◽  
Sea Level ◽  
High Tide ◽  
Water Levels ◽  
Maximum Water Level ◽  
Resonance Properties ◽  
European Shelf ◽  
Defence Strategies ◽  
Sea Level Rise Impacts

<p>Sea-level rise (SLR) can modify not only total water levels, but also tidal dynamics. Several studies have investigated the effects of SLR on the tides of the western European continental shelf (mainly the M2 component). Idier et al. (2017) further investigate this issue using a modelling-based approach, considering uniform SLR scenarios from −0.25 m to +10 m above present-day sea level. Assuming that coastal defences are constructed along present-day shorelines, the patterns of change in high tide levels (annual maximum water level) are spatially similar, regardless of the magnitude of sea-level rise (i.e., the sign of the change remains the same, regardless of the SLR scenario) over most of the area (70%). These changes are generally proportional to SLR, as long as SLR remains smaller than 2 m. Depending on the location, they can account for +/−15% of regional SLR. Changes in high tide levels are much less proportional to SLR when flooding is allowed, in particular in the German Bight. However, some areas (e.g., the English Channel) are not very sensitive to this option, meaning that the effects of SLR would be predictable in these areas, even if future coastal defence strategies are ignored.</p><p>In the present work, we focus on the mechanisms driving these tide changes, especially the bed friction damping, the resonance properties and the reflection at the coast, i.e., local and non-local processes. Additional simulations are done to quantify the effect of these mechanisms on tide changes.</p><p> </p><p>Reference: Idier D., Paris F., Le Cozannet G., Boulahya F., Dumas F. (2017) Sea-level rise impacts on the tides of the European Shelf. Continental Shelf Research, 137, 56-71.</p>

scholarly journals Global distribution of nearshore slopes with implications for coastal retreat

2019 ◽  
Vol 11 (4) ◽  
pp. 1515-1529 ◽  
Author(s):  
Panagiotis Athanasiou ◽  
Ap van Dongeren ◽  
Alessio Giardino ◽  
Michalis Vousdoukas ◽  
Sandra Gaytan-Aguilar ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Sea Level Rise ◽  
Sea Level ◽  
Large Scale ◽  
Input Parameter ◽  
Coastal Processes ◽  
The World ◽  
Important Input ◽  
Significant Spatial Variation ◽  
Coastal Retreat

Abstract. Nearshore slope, defined as the cross-shore gradient of the subaqueous profile, is an important input parameter which affects hydrodynamic and morphological coastal processes. It is used in both local and large-scale coastal investigations. However, due to unavailability of data, most studies, especially those that focus on continental or global scales, have historically adopted a uniform nearshore slope. This simplifying assumption could however have far-reaching implications for predictions/projections thus obtained. Here, we present the first global dataset of nearshore slopes with a resolution of 1 km at almost 620 000 points along the global coastline. To this end, coastal profiles were constructed using global topo-bathymetric datasets. The results show that the nearshore slopes vary substantially around the world. An assessment of coastline recession driven by sea level rise (SLR) (for an arbitrary 0.5 m SLR) with a globally uniform coastal slope of 1 : 100, as carried out in previous studies, and with the spatially variable coastal slopes computed herein shows that, on average, the former approach would underestimate coastline recession by about 40 %, albeit with significant spatial variation. The final dataset has been made publicly available at https://doi.org/10.4121/uuid:a8297dcd-c34e-4e6d-bf66-9fb8913d983d (Athanasiou, 2019).

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