Multiproxy assessment of Holocene relative sea-level changes in the western Mediterranean: Sea-level variability and improvements in the definition of the isostatic signal

Abstract. Vertical land motion (VLM) at the coast is a substantial contributor to relative sea level change. In this work, we present a refined method for its determination, which is based on the combination of absolute satellite altimetry (SAT) sea level measurements and relative sea level changes recorded by tide gauges (TGs). These measurements complement VLM estimates from the GNSS (Global Navigation Satellite System) by increasing their spatial coverage. Trend estimates from the SAT and TG combination are particularly sensitive to the quality and resolution of applied altimetry data as well as to the coupling procedure of altimetry and TGs. Hence, a multi-mission, dedicated coastal along-track altimetry dataset is coupled with high-frequency TG measurements at 58 stations. To improve the coupling procedure, a so-called “zone of influence” (ZOI) is defined, which confines coherent zones of sea level variability on the basis of relative levels of comparability between TG and altimetry observations. Selecting 20 % of the most representative absolute sea level observations in a 300 km radius around the TGs results in the best VLM estimates in terms of accuracy and uncertainty. At this threshold, VLMSAT-TG estimates have median formal uncertainties of 0.58 mm yr−1. Validation against GNSS VLM estimates yields a root mean square (rmsΔVLM) of VLMSAT-TG and VLMGNSS differences of 1.28 mm yr−1, demonstrating the level of accuracy of our approach. Compared to a reference 250 km radius selection, the 300 km zone of influence improves trend accuracies by 15 % and uncertainties by 35 %. With increasing record lengths, the spatial scales of the coherency in coastal sea level trends increase. Therefore, the relevance of the ZOI for improving VLMSAT-TG accuracy decreases. Further individual zone of influence adaptations offer the prospect of bringing the accuracy of the estimates below 1 mm yr−1.

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

BSGF - Earth Sciences Bulletin ◽

10.1051/bsgf/2017190 ◽

2017 ◽

Vol 188 (4) ◽

pp. 24 ◽

Cited By ~ 3

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.

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Multidisciplinary Study of Marine Archives: Reconstruction of Sea-Level, Sediment Yields, Sediment Sources, Paleoclimate, Paleoceanography and Vertical Movement on Margins: Examples from the Western Mediterranean Sea

Recent Research on Geomorphology, Sedimentology, Marine Geosciences and Geochemistry - Advances in Science, Technology & Innovation ◽

10.1007/978-3-030-72547-1_56 ◽

2022 ◽

pp. 265-270

Author(s):

Marina Rabineau ◽

Romain Pellen ◽

Virgil Pasquier ◽

Massimo Bellucci ◽

Shray Badhani ◽

...

Keyword(s):

Mediterranean Sea ◽

Sea Level ◽

Vertical Movement ◽

Western Mediterranean ◽

Sediment Sources ◽

Sediment Yields ◽

Multidisciplinary Study ◽

Western Mediterranean Sea

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Submerged Speleothems and Sea Level Reconstructions: A Global Overview and New Results from the Mediterranean Sea

10.20944/preprints202105.0100.v1 ◽

2021 ◽

Author(s):

Fabrizio Antonioli ◽

Stefano Furlani ◽

Paolo Montagna ◽

Paolo Stocchi ◽

Lucio Calcagnile ◽

...

Keyword(s):

Mediterranean Sea ◽

Sea Level ◽

Additional Data ◽

Late Quaternary ◽

Sea Level Changes ◽

Central Mediterranean ◽

Relative Sea Level ◽

Central Mediterranean Sea ◽

Regional Sea Level ◽

Sea Level Variations

This study presents a world review as well as new additional data in form of submerged speleothems that are used for paleo sea level reconstructions. Speleothems significantly contributed to the understanding of the global and regional sea level variations during the Middle and Late Quaternary. The studied speleothems cover the last 1.4 Myr and are focused mainly on Marine Isotope Stages (MIS) 1, 2, 3, 5.1, 5.3, 5.5, 7.1, 7.2, 7.3 and 7.5. Results reveal that submerged speleothems represent extraordinary archives providing detailed information on former sea level changes. We present also new results from stalactites collected in central Mediterranean sea, at Favignana and Ustica islands (Sicily, Italy), both characterized by continental, phreatic or marine layers. The study and analysis of the latter speleothems provide results of great interest for relative sea level changes over the last 1000 years.

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Western Mediterranean sea-level rise: Changing exchange flow through the Strait of Gibraltar

Geophysical Research Letters ◽

10.1029/2000gl011653 ◽

2000 ◽

Vol 27 (18) ◽

pp. 2949-2952 ◽

Cited By ~ 34

Author(s):

Tetjana Ross ◽

Chris Garrett ◽

Pierre-Yves Le Traon

Keyword(s):

Sea Level Rise ◽

Mediterranean Sea ◽

Sea Level ◽

Western Mediterranean ◽

Exchange Flow ◽

Strait Of Gibraltar ◽

Western Mediterranean Sea ◽

Flow Through

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Annual cycles of sea level and sea surface temperature in the western Mediterranean Sea

Journal of Geophysical Research Atmospheres ◽

10.1029/2002jc001365 ◽

2003 ◽

Vol 108 (C3) ◽

Cited By ~ 13

Author(s):

Catherine Bouzinac

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Mediterranean Sea ◽

Sea Level ◽

Western Mediterranean ◽

Sea Surface ◽

Annual Cycles ◽

Western Mediterranean Sea

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

Applied Sciences ◽

10.3390/app11094009 ◽

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.

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