Fig 1 – Map of the potential submersion of the Port of Syracuse according to one of the IPCC scenarios at 2050 (in yellow) and at 2100 (in red)
Fig 2 – The coast south of Catania at the airport
The evaluation of the loss of emerged lands in the coming decades in the study of a team of researchers from INGV and the Universities of Bari and Catania
The coasts of south-eastern Sicily could undergo progressive submersion, with a presumed loss of about 10 sq km of surface in 2100, due to climate change on the planet.
These are the results of a study carried out as part of the large project Dynamic Planet which the Ministry of Research and University (MUR) has financed to the National Institute of Geophysics and Volcanology (INGV).
A systematic review Relative Sea-Level Rise Scenario for 2100 along the Coast of South Eastern Sicily (Italy) by InSAR Data, Satellite Images and High-Resolution Topography, carried out by INGV in collaboration with the “Aldo Moro” University of Bari, the University of Catania and the Radboud University in the Netherlands, has just been published in the international journal 'Remote Sensing'.
“We know that since 1880 sea level has started to rise by 14-17 cm but today it is accelerating and rising at the rate of more than 30 cm per century”, explains Prof. Giovanni Scicchitano, associate of Geomorphology at the Department of Earth and Geoenvironmental Sciences of the University of Bari.
In recent years, global warming is causing the melting of continental ice and the thermal expansion of the oceans, as reported in the latest report by the IPCC (Intergovernmental Panel on Climate Change). It illustrates the relationships between greenhouse gases, increase in global temperatures and increase in sea level: factors that also have repercussions on the coasts of Sicily.
“In particular, if greenhouse gas emissions are not reduced, sea level could rise by as much as 1.1 meters in 2100 and several meters in the following two-three centuries, with a consequent impact on the coasts. But low-lying and subsiding waters, i.e. where the earth's surface moves downwards due to natural or anthropic causes, can accelerate the process of marine invasion. For these reasons we have carried out a study on the expected scenarios along the coasts of eastern Sicily for 2050 and 2100", continues Prof. Scicchitano.
The area has been well known by the research team since the Augusta earthquake of December 13, 1990. In particular, with multidisciplinary studies, scientists have created accurate scenarios of the expected effects caused by ground movements and sea level rise along the coastal strip.
Marco Anzidei, INGV researcher and first author of the research says “We calculated sea level rise projections for different climate scenarios and based on various parameters issued by the IPCC or calculated in this study, including sea thermal expansion, continental ice melt, gas concentration greenhouse in the atmosphere and, finally, the vertical movements of the soil. Together with INGV researchers Cristiano Tolomei, Christian Bignami and Enrico Serpelloni, we evaluated ground deformations with spatial data, essential information for creating high-resolution maps of areas that will potentially be flooded in 2050 and 2100. The analyzes followed the methodologies developed in projects SAVEMEDCOASTS e SAVEMEDCOASTS-2, coordinated by INGV and financed by the European Civil Protection (DG ECHO), which are providing new information on the scenarios expected in the Mediterranean in the coming years”.
Anzidei continues, “In the study of the coasts of eastern Sicily we have used various analytical techniques aimed at defining all the components involved in the relative rise of the sea level. We used satellite data to calculate subsidence rate and coast retreat, tidal data for sea level trends and high-resolution digital models of the land surface along the coastal strip, calibrated with high-precision topographic survey campaigns . In the calculation, we have considered the effects of regional tectonics and subsidence using spatial techniques that include the networks of INGV permanent GPS stations and data from Sentinel interferometric satellites. These analyzes allowed us to evaluate the scenarios in six coastal areas which include the southern part of the plain of Catania, the ports of Augusta and Syracuse, the mouth of the Asinaro, Vendicari and Marzamemi”.
Prof. Carmelo Monaco, full professor of Structural Geology at the Department of Biological, Geological and Environmental Sciences of the University of Catania, explains “The results obtained have, in addition to a great methodological relevance, a particular importance in terms of assessment of the vulnerability and risk of the coastal areas of south-eastern Sicily. In our work we have chosen these six areas because they are of particular importance for the regional territory: the Catania plain with an intense agricultural vocation, the ports of Augusta and Syracuse, of particular commercial and industrial importance and finally Vendicari and Marzamemi, particularly relevant from the point of view from an environmental and tourist point of view. The results for the plain of Catania indicate that, in the area between the Simeto and San Leonardo rivers, the loss of territory by 2100 would be considerable, with the sea invading the depressed area for several hundred metres. In the port of Augusta some industrial areas could be involved. The port of Syracuse is the area that would suffer the most from a potential sea level rise in 2100: according to our projections, in fact, the area of the mouth of the Ciane river could be invaded by the sea for an extension of up to 1 km in the inland from the present shoreline. The Saline of the Ciane river, currently an Oriented Nature Reserve and which in recent years have already suffered a retreat measured by satellite data of about 70 meters, would be totally submerged. A similar fate could befall the Vendicari Reserve, whose wetlands could disappear leaving scattered relict islands".
"To these scenarios it should be added that, as estimated by various studies published in recent years, in conditions of global warming even storms could have stronger effects on these coastal areas", adds Prof. Scicchitano. “It's another phenomenon that we are paying attention to and analyzing. In a recent study that we conducted in collaboration with the University of Catania and the Marine Protected Area of Plemmirio (Syracuse), which we will present at the next congress of the European Geophysical Union, we verified that in recent years Mediterranean hurricanes, known as 'medicane', they hit the coasts of south-eastern Sicily (remember Quendresa in 2014 and Zorbas in 2018) and produced more intense effects than those generated by normal seasonal storms that occurred in the last 10 years”.
Therefore, with a higher sea level, the effects of extreme marine weather events would be magnified. “Therefore, there is a need to continue research also in other coastal areas but, above all, it becomes necessary to increase the awareness of the population on the expected effects. At the same time, the national and international community should pay more attention to the phenomenon of sea level rise caused by ongoing climate change", the researchers conclude.
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