Spatial Variation of Sea Level Rise at Atlantic and Mediterranean Coastline of Europe

We analyzed a set of geodetic data to investigate the contribution of local factors, namely the sea level natural variability (SLNV) and the vertical land motion (VLM), to the sea-level trend. The SLNV is analyzed through the Empirical Mode Decomposition (EMD) on tidal data (>60 years of recordings) and results are used to evaluate its effects on sea levels. The VLM is measured at a set of continuous GPS (cGPS) stations (>5 years of recordings), located nearby the tide gauges. By combining VLM and SLNV with IPCC-AR5 regional projections of climatic data (Representative Concentration Pathways (RCP) 2.6 and 8.5), we provide relative sea-level rise projections by 2100. Results show that the combined effects of SLNV and VLM are not negligible, contributing between 15% and 65% to the sea-level variability. Expected sea levels for 2100 in the RCP8.5 scenario are between 475 ± 203 (Bakar) and 818 ± 250 mm (Venice). In the Venice Lagoon, the mean land subsidence at 3.3 ± 0.85 mm a −1 (locally up to 8.45 ± 1.69 mm a −1 ) is driving the local sea-level rise acceleration.At time scales of years or decades, oceanographic and climatic factors drive non-stationary sea-level fluctuations, the so-called sea-level natural variability, whose assessment is important for future sea-level projections since their contribution is not negligible [16][17][18][19][20][21][22][23][24][25][26], (http://www.ipcc.ch). For example, in the Indian Ocean the effects of the natural variability, mainly driven by the decadal El Niño-Southern Oscillation (ENSO), Indian Ocean Dipole (IOD) and monsoon, dominate the external forcing contributing up 85% of the observed trend [27]. In the Mediterranean basin, the glacio-isostatic contribution, acting from the Last Glacial Maximum, has a predictable pattern that has been estimated and compared with direct observational data in deforming zones [4,9,15]. The vertical land motion due to natural (tectonics, isostasy and ground compaction) [4,9,13], and/or anthropogenic factors (fluid extraction) [28,29], produces changes in the shape of the basins and changes in the height of the land with respect to the sea (see e.g., [9,13] and references therein). Although this effect does not directly change the quantity of water and its physical properties it results in a net increase (in case of subsidence) or decrease (in case of uplift) of the sea level, when evaluated in restricted geographical areas (as for example the punctual measurements by tide gauges), since the land is moving. If the vertical land motion operates over time it locally results in a net sea-level rate that adds up to the rate induced by GIA, thus affecting the local sea-level change. Tide gauge records are strongly sensitive to the vertical land motion since these instruments are tied to land. Although the role and rates of the main contributors to the sea-level rise are still debated [30], it is a matter of fact that most of the coasts of the world are undergoing the effects of the continuing sea-level rise. The vertical motion due to tectonic ef...

supporting

confidence: 86%

supporting

confidence: 86%

mentioning

confidence: 99%

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Natural Variability and Vertical Land Motion Contributions in the Mediterranean Sea-Level Records over the Last Two Centuries and Projections for 2100

Vecchio

Anzidei

Serpelloni

et al. 2019

“…Climate change, induced land cover/use changes, eutrophication and hydrological alteration are the main threats of benthic macrophytes in transitional water ecosystems [84]. The high temperatures predicted for the Mediterranean area through the end of 21st century will significantly impact the biodiversity of coastal lagoons [85]. Conservation actions such as the improvement of water quality by the reduction of pollution sources, water drainage and habitat modifications are needed to preserve macrophyte species.…”

Section: Discussionmentioning

confidence: 99%

Environmental Variability and Macrophyte Assemblages in Coastal Lagoon Types of Western Greece (Mediterranean Sea)

Christia

Giordani

Papastergiadou

2018

Coastal lagoon types of Western Greece were allocated to a spectrum of meso to polyhaline chocked lagoons; poly to euhaline restricted lagoons; and euhaline restricted lagoons along the Ionian Sea coast. This diversity comprises wide ranges of physical, chemical and environmental parameters in a seasonal and annual scale, which explains the variability in the distribution of benthic macrophytes. Four different macrophyte assemblages were distinguished, characterized by annual or perennial species. Extensive statistical analysis showed that salinity and nitrate concentrations had a great impact on the composition and distribution of macrophyte assemblages into lagoon types that also changed their abundance on a seasonal and annual scale. During the monitoring period, an important salinity shift in a chocked lagoon might cause the gradual loss of Zostera noltii and its replacement by Ruppia cirrhosa. Restricted lagoons were characterized by higher species diversity, while the other three identified macrophyte assemblages were dominated by the angiosperms Ruppia cirrhosa and Cymodocea nodosa. This integrated study of coastal lagoons is likely to be broadly applicable, since it was based on important parameters affecting such ecosystems, and the provided links between macrophyte assemblages and abiotic factors are of critical importance to improve management and environmental policies.

“…More recently, similar estimates are also provided for spatial variation of SLR over various regions of World's oceans [25]. Along this line of work, SLR estimates (0.00-0.4518 m) for the Mediterranean Sea is also reported in [26].…”

Section: Introductionmentioning

confidence: 64%

Climate Change Risk Evaluation of Tsunami Hazards in the Eastern Mediterranean Sea

Yavuz

Kentel

Aral

2020

Climate change impacts on social and economic assets and activities are expected to be devastating. What is as important as the analysis of climate change triggered events is the analysis of a combination of climate change related events and other natural hazards not related to climate change. Given this observation, the purpose of this study is to present a coastal risk analysis for potential earthquake triggered tsunamis (ETTs) coupled with the sea level rise (SLR) in the Eastern Mediterranean Sea. For this purpose, extensive stochastic analysis of ETTs, which are not related to climate change, are conducted considering the effects of climate change related SLR projections for this century. For the combined analysis, economic and social risks are evaluated for two regions in the Eastern Mediterranean Coastline, namely the Fethiye City Center at the Turkish Coastline and the Cairo Agricultural Area near Egypt. It is observed that ignoring SLR will hinder realistic evaluation of ETT risks in the region. Moreover, spatial evaluations of economic and social risks are necessary since topography and proximity to the earthquake zones affect inundation levels due to ETTs in the presence of SLR.