Experimental determination of the friction coefficient for estimating sea storm induced megaboulders movements.

The presence of numerous boulders on rocky coast is linked to phenomena of detachment and deposit due to the occur-rence of sea storms. Currently, several hydrodynamic equations are known in the bibliography to estimate the wave height able to dis-place them, applying geometric parameters and hydrodynamic coefficients. A new methodological approach intends to consider the minimum energy required for the linear movement of a boulder along a weakly sloping rocky surface as a function of the friction coefficient

Pleistocene terracing phases in the metropolitan area of Bari - AAR dating and deduced uplift rates of the Apulian Foreland

We performed detailed geological and geomorphological analyses on a series of marine terraces located around the city of Bari (southern Italy). Absolute dating was obtained by applying amino acid racemisation (AAR) to ostracod valves taken from deposits lying on marine terraces. The combination of literature data, feld geological surveys, digital terrain model analysis, and absolute dating allowed us to recognise and map: i) four terrace surfaces bordered by four inner edges which date to MIS 7.5, 7.3, 7.1, and 5.5; and ii) three terraced deposits, which date to MIS 7.5, 7.1, and 5.5. These new data represent the frst dated terraced deposits (older than MIS 5) of the coastal stretch of the Apulian foreland between Trani and Taranto. Using inner edges of the terraces as palaeo sea level markers, we calculate the mean uplift rates that characterised this portion of the Apulian foreland from MIS 7.5, 7.3, 7.1, 5.5 to the present day; these rates are 0.28, 0.255, 0.15 and 0.01 mm/y, respectively. These new dated Pleistocene terraced deposits allow to refne the knowledge on the chronology, the spatial extension and rate of the uplift and, in general, on the Pleistocene geodynamics of the Apulian foreland

Relative Sea-Level Rise and Potential Submersion Risk for 2100 on 16 Coastal Plains of the Mediterranean Sea.

The coasts of the Mediterranean Sea are dynamic habitats in which human activities have been conducted for centuries and which feature micro-tidal environments with about 0.40 m of range. For this reason, human settlements are still concentrated along a narrow coastline strip, where any change in the sea level and coastal dynamics may impact anthropic activities. In the frame of the RITMARE and the Copernicus Projects, we analyzed light detection and ranging (LiDAR) and Copernicus Earth Observation data to provide estimates of potential marine submersion for 2100 for 16 small-sized coastal plains located in the Italian peninsula and four Mediterranean countries (France, Spain, Tunisia, Cyprus) all characterized by different geological, tectonic and morphological features. The objective of this multidisciplinary study is to provide the first maps of sea-level rise scenarios for 2100 for the IPCC RCP 8.5 and Rahmstorf (2007) projections for the above affected coastal zones, which are the locations of touristic resorts, railways, airports and heritage sites. On the basis of our model (eustatic projection for 2100, glaciohydrostasy values and tectonic vertical movement), we provide 16 high-definition submersion maps. We estimated a potential loss of land for the above areas of between about 148 km(2)(IPCC-RCP8.5 scenario) and 192 km(2)(Rahmstorf scenario), along a coastline length of about 400 km

New evidence of MIS 3 relative sea level changes from the Messina Strait, Calabria (Italy)

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Antonioli, F., Calcagnile, L., Ferranti, L., Mastronuzzi, G., Monaco, C., Orru, P., Quarta, G., Pepe, F., Scardino, G., Scicchitano, G., Stocchi, P., & Taviani, M. New evidence of MIS 3 relative sea level changes from the Messina Strait, Calabria (Italy). Water, 13(19), (2021): 2647, https://doi.org/10.3390/w13192647.Investigation of sea-level positions during the highly-dynamic Marine Isotope Stage 3 (MIS 3: 29–61 kyrs BP) proves difficult because: (i) in stable and subsiding areas, coeval coastal sediments are currently submerged at depths of few to several tens of meters below the present sea level; (ii) in uplifting areas, the preservation of geomorphic features and sedimentary records is limited due to the erosion occurred during the Last Glacial Maximum (LGM) with sea level at a depth of −130 m, followed by marine transgression that determined the development of ravinement surfaces. This study discusses previous research in the Mediterranean and elsewhere, and describes new fossiliferous marine deposits overlaying the metamorphic bedrock at Cannitello (Calabria, Italy). Radiocarbon ages of marine shells (about 43 kyrs cal BP) indicate that these deposits, presently between 28 and 30 m above sea level, formed during MIS 3.1. Elevation correction of the Cannitello outcrops (considered in an intermediate-to-far-field position with respect to the ice sheet) with the local vertical tectonic rate and Glacial Isostatic Adjustment (GIA) rate allows the proposal of a revision of the eustatic depth for this highstand. Our results are consistent with recently proposed estimates based on a novel ice sheet modelling technique.This research received no external funding

Sea-Level Rise and Shoreline Changes Along an Open Sandy Coast: Case Study of Gulf of Taranto, Italy

The dynamics of the sandy coast between Castellaneta and Taranto (Southern Italy) has been influenced by many natural and anthropogenic factors, resulting in significant changes in the coastal system over the last century. The interactions between vertical components of sea-level changes and horizontal components of the sedimentary budget, in combination with anthropogenic impact, have resulted in different erosion and accretion phases in the past years. Local isostatic, eustatic, and vertical tectonic movements, together with sedimentary budget changes, must be considered in order to predict the shoreline evolution and future marine submersion. In this study, all morpho-topographic data available for the Gulf of Taranto, in combination with Vertical Land Movements and sea-level rise trends, were considered by assessing the local evolution of the coastal trend as well as the future marine submersion. Based on the predicted spatial and temporal coastal changes, a new predictive model of submersion was developed to support coastal management in sea-level rise conditions over the next decades. After that, a multi-temporal mathematical model of coastal submersion was implemented in a Matlab environment. Finally, the effects of the relative sea-level rise on the coastal surface prone to submersion, according to the Intergovernmental Panel on Climate Change Assessment Reports (AR) 5 Representative Concentration Pathways (RCP) 2.6 and RCP 8.5 scenarios, were evaluated up to 2100

Assessment of Medicane Helios meteo-marine parameters using a machine learning approach

<p>Medicanes represent a unique weather phenomenon in the Mediterranean Sea, combining features of both tropical and extra-tropical cyclones. The recent Medicanes Helios induced a severe windstorm that caused storm surges and flooding impacting coastal regions of southeastern Sicily. To assess the hydrodynamic parameters, such as tide phase, storm surge and wave flow induced by Medicane "Helios", an innovative machine learning system called LEUCOTEA was used. This system takes into account a combined approach of Geomorphological surveys, Convolutional Neural Network, and Optical Flow techniques with real-time video records. The system provides the values of tide phases, storm surge and wave flow that could be useful for policymarkers and environmental managers as a valuable tool to assess the potential coastal risks and to develop appropriate mitigation and adaption strategies.</p&gt

An Integrated Approach between Multispectral Satellite Images and Geophysical and Morpho-Topographic Surveys for the Detection of Water Stress Associated with Coastal Dune Erosion

Coastal erosion occurs due to different processes involving physical and ecological systems. One of these factors is the degree of water stress experienced by dune vegetation. While healthy dune vegetation can help to stabilize the dune systems, water-stressed vegetation can instead enhance dune erosion. In this study, remote sensing techniques were used to monitor the water stress affecting the dune vegetation in dune systems along the alluvial plain of the Chiatona coast (Apulia, Southern Italy) located on the Ionian Arc. Multispectral satellite data from Landsat 8/9 and Sentinel-2 were used to assess the water stress at different spatial scales over a 4-year monitoring period from 2019 to 2023. The normalized difference vegetation index (NDVI) and the normalized difference moisture index (NDMI) were used to identify dune surfaces that were experiencing water stress. Furthermore, a terrestrial laser scanner and LiDAR data were acquired at different temporal ranges in areas affected by water stress to highlight coastal changes in areas associated with unhealthy dune vegetation. A large drop in NDVI values was observed in May 2020 due to the occurrence of coastal fires in some parts of the Chiatona coast. Geoelectrical surveys were conducted to investigate if coastal fires were capable of saline groundwater contamination, potentially enhancing dune erosion in these areas. The joint analysis of remote sensing, topographical, and geoelectric data showed that water stress reduced the amount of healthy dune vegetation, triggering dune deflation processes that resulted in increased coastal erosion rates, while also leading to the saline contamination of groundwater

Coastal Quarries as Relative Sea-Level Markers: A Methodological Approach Applied in the Apulia Region (Southern Italy)

The assessment of past sea-level positions requires a multidisciplinary approach that involves both scientific and historical humanistic fields. The use of a multidisciplinary approach allows us to obtain reliable information on the relative sea-level position, the determination of which requires the evaluation of the eustatic and steric components as well as an assessment of the vertical ground displacements, such as the isostatic adjustments and tectonic movements. In this context, coastal geoarchaeological markers play a fundamental role since their architectural height (generally defined as functional height) was relative to the sea level at the time of their construction. Thus, a comparison between the current elevation of geoarchaeological structures (or depth in the case they are currently submerged) with their estimated functional height allows us to obtain the relative sea-level variation. In this study, we applied a methodological procedure for the evaluation of the functional height of architectural elements using modern technologies (Terrestrial Laser Scanner and GPS-Real Time Kinematic) and detailed sea-level analysis. The proposed methodology was applied to coastal quarries located along the coast of Bari (Apulia region, southern Italy). The results allowed us to confirm the functional height of the detachment surface reported in the literature and to assess the sea-level position in the fifth and fourth centuries before Christ

Coastal Quarries as Relative Sea-Level Markers: A Methodological Approach Applied in the Apulia Region (Southern Italy)

The assessment of past sea-level positions requires a multidisciplinary approach that involves both scientific and historical humanistic fields. The use of a multidisciplinary approach allows us to obtain reliable information on the relative sea-level position, the determination of which requires the evaluation of the eustatic and steric components as well as an assessment of the vertical ground displacements, such as the isostatic adjustments and tectonic movements. In this context, coastal geoarchaeological markers play a fundamental role since their architectural height (generally defined as functional height) was relative to the sea level at the time of their construction. Thus, a comparison between the current elevation of geoarchaeological structures (or depth in the case they are currently submerged) with their estimated functional height allows us to obtain the relative sea-level variation. In this study, we applied a methodological procedure for the evaluation of the functional height of architectural elements using modern technologies (Terrestrial Laser Scanner and GPS-Real Time Kinematic) and detailed sea-level analysis. The proposed methodology was applied to coastal quarries located along the coast of Bari (Apulia region, southern Italy). The results allowed us to confirm the functional height of the detachment surface reported in the literature and to assess the sea-level position in the fifth and fourth centuries before Christ

The enigmatic 1693 AD tsunami in the eastern Mediterranean Sea: new insights on the triggering mechanisms and propagation dynamics

The disastrous earthquake of 1693 AD caused over 60,000 causalities and the total destruction of several villages and towns in south-eastern Sicily. Immediately after the earthquake, a tsunami struck the Ionian coasts of Sicily and the Messina Strait and was probably recorded even in the Aeolian Islands and Malta. Over the last few decades, the event has been much debated regarding the location of the seismogenic source and the possible cause of the associated tsunami. The marine event has been related to both a submarine landslide and a coseismic displacement at the seafloor. To better define the most reliable sources and dynamics of the tsunami, we couple high-resolution marine seismic survey data with hydrodynamic modelling to simulate various scenarios of tsunami generation and propagation. Results from the simulations are compared with geomorphological evidence of past tsunami impacts, described in previous work along the coast of south-eastern Sicily, and within historical chronicles and reports. The most reliable scenario considers the 1693 event composed by two different tsunami waves: a first wave generated by the coseismic fault displacement at the seafloor and a second wave generated by a submarine landslide, triggered by the earthquake shaking. Tsunami modelling shows that a simultaneous movement between fault displacement and submarine mass movement could determine a destructive interference on the tsunami waves, resulting in a reduction in wave height. For this reason, the second tsunami wave probably occurred with a maximum delay of few minutes after the one generated by the earthquake and induced a greater flooding. The double-source model could explain the observation because in the course of other destructive earthquakes in south-eastern Sicily, such as that of 1169 AD, the associated tsunami caused less damages. This implies the need to better map, define and assess the hazard responsible for this type of tsunami events