scholarly journals Shoreline Response to Wave Forcing and Sea Level Rise along a Geomorphological Complex Coastline (Western Sardinia, Mediterranean Sea)

2021 ◽  
Vol 11 (9) ◽  
pp. 4009
Author(s):  
Simone Simeone ◽  
Luca Palombo ◽  
Emanuela Molinaroli ◽  
Walter Brambilla ◽  
Alessandro Conforti ◽  
...  
Keyword(s):  
Grain Size ◽  
Sea Level Rise ◽  
Mediterranean Sea ◽  
Sea Level ◽  
Morphological Changes ◽  
Wave Climate ◽  
Western Mediterranean ◽  
Single Beam ◽  
Western Mediterranean Sea ◽  
Submerged Area

Beaches responses to storms, as well as their potential adaptation to the foreseeable sea level rise (SLR), were investigated along three beaches in a coastal tract in western Sardinia (Western Mediterranean Sea). The grain size of the sediments, the beach profile variability and the wave climate were analyzed in order to relate morphological changes, geological inheritances and waves forcing. Multibeam, single-beam and lidar data were used to characterize the inner shelf morphologies and to reproduce the flooding due to the SLR. The studied beaches experienced major changes when consecutive storms, rather than singles ones, occurred along the coastline. The sediment availability, the grain size and the geomorphological structure of the beaches were the most important factors influencing the beach response. On the sediment-deprived coarse beaches the headlands favor the beach rotation, and the gravel barrier morphology can increase the resistance against storms. On the sediment-abundant beaches, the cross-shore sediment transport towards a submerged area leads to a lowering in the subaerial beach level and a contemporaneous shoreline retreat in response to storms. A very limited ingression of the sea is related to the SLR. This process may affect (i) the gravel barrier, promoting a roll over due to the increase in overwash; (ii) the embayed beach increasing its degree of embayment as headlands become more prominent, and (iii) the sediment-abundant beach with an erosion of the whole subaerial beach during storms, which can also involve the foredune area.

scholarly journals Repeated fluid expulsions during events of rapid sea-level rise in the Gulf of Lion, western Mediterranean Sea

2017 ◽  
Vol 188 (4) ◽  
pp. 24 ◽  
Author(s):  
Aurélien Gay ◽  
Thibault Cavailhès ◽  
Dominique Grauls ◽  
Bruno Marsset ◽  
Tania Marsset
Keyword(s):  
Sea Level Rise ◽  
Mediterranean Sea ◽  
Sea Level ◽  
Western Mediterranean ◽  
Unconsolidated Sediments ◽  
Geometrical Parameters ◽  
Near Surface ◽  
Western Mediterranean Sea ◽  
Gulf Of Lion ◽  
Potential Fluid

Based on a High-Resolution 3D seismic block acquired in the Gulf of Lion in 2004–2005 we investigated fluid pipes and pockmarks on the top of the interfluve between the Hérault canyon and the Bourcart canyon both created by turbidity currents and gravity flows from the shelf to the deep basin in the north-western Mediterranean Sea. Combining the geometry of the potential fluid pipes with the induced deformation of surrounding sediments leads then to the ability to differentiate between potential fluid sources (root vs source) and to better estimate the triggering mechanisms (allochtonous vs. autochtonous cause). We linked together a set of derived attributes, such as Chaos and RMS amplitude, to a 3D description of pipes along which fluids may migrate. As previously shown in other basins, the induced deformation, creating cone in cone or V-shaped structures, may develop in response to the fluid pipe propagation in unconsolidated sediments in the near surface. The level at the top of a cone structure is diachronous. It means that stratigraphic levels over this surface are deformed at the end of the migration. They collapse forming a depression called a pockmark. These pipes are the result of repeated cycles of fluid expulsion that might be correlated with rapid sea-level rise instead of sediment loading. The most recent event (MIS 2.2 stage) has led to the formation of a pockmark on the modern seafloor. It has been used as a reference for calculating the effect of a rapid sea-level rise on fluid expulsion. As all physical and geometrical parameters are constrained, we were able to define that a + 34 m of sea level rise may account for triggering fluid expulsion from a very shallow silty-sandy layer at 9 m below seafloor since the last glacial stage. This value is consistent with a sea level rise of about 102 m during this period. This study shows that the episodic nature of fluid release resulted from hydromechanical processes during sea-level rise due to the interactivity between high pressure regimes and principal in situ stresses.

scholarly journals Dynamical Downscaling of ERA5 Data on the North-Western Mediterranean Sea: From Atmosphere to High-Resolution Coastal Wave Climate

2021 ◽  
Vol 9 (2) ◽  
pp. 208
Author(s):  
Valentina Vannucchi ◽  
Stefano Taddei ◽  
Valerio Capecchi ◽  
Michele Bendoni ◽  
Carlo Brandini
Keyword(s):  
Mediterranean Sea ◽  
Wind Wave ◽  
Dynamical Downscaling ◽  
Wave Climate ◽  
Western Mediterranean ◽  
Limited Area ◽  
Computational Domain ◽  
Wave Hindcast ◽  
The North ◽  
Western Mediterranean Sea

A 29-year wind/wave hindcast is produced over the Mediterranean Sea for the period 1990–2018. The dataset is obtained by downscaling the ERA5 global atmospheric reanalyses, which provide the initial and boundary conditions for a numerical chain based on limited-area weather and wave models: the BOLAM, MOLOCH and WaveWatch III (WW3) models. In the WW3 computational domain, an unstructured mesh is used. The variable resolutions reach up to 500 m along the coasts of the Ligurian and Tyrrhenian seas (Italy), the main objects of the study. The wind/wave hindcast is validated using observations from coastal weather stations and buoys. The wind validation provides velocity correlations between 0.45 and 0.76, while significant wave height correlations are much higher—between 0.89 and 0.96. The results are also compared to the original low-resolution ERA5 dataset, based on assimilated models. The comparison shows that the downscaling improves the hindcast reliability, particularly in the coastal regions, and especially with regard to wind and wave directions.

scholarly journals Changes in beach shoreline due to sea level rise and waves under climate change scenarios: application to the Balearic Islands (Western Mediterranean)

2016 ◽  
Author(s):  
Alejandra R. Enríquez ◽  
Marta Marcos ◽  
Amaya Álvarez-Ellacuría ◽  
Alejandro Orfila ◽  
Damià Gomis
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Climate Models ◽  
Regional Climate ◽  
Wave Climate ◽  
Sandy Beaches ◽  
Western Mediterranean ◽  
Climate Change Scenarios ◽  
Swash Zone ◽  
Climate Scenarios

Abstract. In this work we assess the impacts in reshaping coastlines as a result of sea level rise and changes in wave climate. The methodology proposed combines the SWAN and SWASH wave models to resolve the wave processes from deep waters up to the swash zone in two micro-tidal sandy beaches in Mallorca Island, Western Mediterranean. In a first step, the modelling approach is validated with observations from wave gauges and from the shoreline inferred from video monitoring stations, showing a good agreement between them. Afterwards, the modelling setup is applied to the 21st century sea level and wave projections under two different climate scenarios, RCP45 and RCP85. Sea level projections were retrieved from state of the art regional estimates, while wave projections were obtained from regional climate models. Changes in the coastline are explored under mean and extreme wave conditions. Our results indicate that the studied beaches would suffer a coastal retreat between 7 and up to 50 m, equivalent to half of the present-day aerial beach surface, under the climate scenarios considered.

scholarly journals Impact of relative sea level and rapid climate changes on the architecture and lithofacies of the Holocene Rhone subaqueous delta (Western Mediterranean Sea)

2014 ◽  
Vol 305 ◽  
pp. 35-53 ◽  
Author(s):  
Anne-Sophie Fanget ◽  
Serge Berné ◽  
Gwénaël Jouet ◽  
Maria-Angela Bassetti ◽  
Bernard Dennielou ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Climate Changes ◽  
Western Mediterranean ◽  
Relative Sea Level ◽  
The Holocene ◽  
Western Mediterranean Sea

scholarly journals Changes in beach shoreline due to sea level rise and waves under climate change scenarios: application to the Balearic Islands (western Mediterranean)

2017 ◽  
Vol 17 (7) ◽  
pp. 1075-1089 ◽  
Author(s):  
Alejandra R. Enríquez ◽  
Marta Marcos ◽  
Amaya Álvarez-Ellacuría ◽  
Alejandro Orfila ◽  
Damià Gomis
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Climate Models ◽  
Regional Climate ◽  
Wave Climate ◽  
Sandy Beaches ◽  
Western Mediterranean ◽  
Climate Change Scenarios ◽  
Swash Zone ◽  
Climate Scenarios

Abstract. This work assesses the impacts in reshaping coastlines as a result of sea level rise and changes in wave climate. The methodology proposed combines the SWAN and SWASH wave models to resolve the wave processes from deep waters up to the swash zone in two micro-tidal sandy beaches in Mallorca island, western Mediterranean. In a first step, the modelling approach has been validated with observations from wave gauges and from the shoreline inferred from video monitoring stations, showing a good agreement between them. Afterwards, the modelling set-up has been applied to the 21st century sea level and wave projections under two different climate scenarios, representative concentration pathways RCP45 and RCP85. Sea level projections have been retrieved from state-of-the-art regional estimates, while wave projections were obtained from regional climate models. Changes in the shoreline position have been explored under mean and extreme wave conditions. Our results indicate that the studied beaches would suffer a coastal retreat between 7 and up to 50 m, equivalent to half of the present-day aerial beach surface, under the climate scenarios considered.

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