Time filter

Source Type

Genova, Italy

Casella E.,Leibniz Center for Tropical Marine Ecology | Casella E.,SEAMap srl | Rovere A.,Leibniz Center for Tropical Marine Ecology | Rovere A.,University of Bremen | And 6 more authors.
Geo-Marine Letters | Year: 2016

The aim of this study was to evaluate topographic changes along a stretch of coastline in the Municipality of Borghetto Santo Spirito (Region of Liguria, Italy, north-western Mediterranean) by means of a remotely piloted aircraft system coupled with structure from motion and multi-view stereo techniques. This sector was surveyed three times over 5 months in the fall–winter of 2013–2014 (1 November 2013, 4 December 2013, 17 March 2014) to obtain digital elevation models and orthophotos of the beach. Changes in beach topography associated with storm action and human activities were assessed in terms of gain/loss of sediments and shifting of the wet–dry boundary defining the shoreline. Between the first and second surveys, the study area was hit by two storms (10–11 November 2013 and 21–22 November 2013) with waves approaching from the E–NNE, causing a shoreline retreat which, in some sectors, reached 7 m. Between the second and third surveys, by contrast, four storms (25–27 December 2013, 5–6 January 2014, 17–18 January 2014 and 6–10 February 2014) with waves propagating from the SE produced a general advancement of the shoreline (up to ~5 m) by deposition of sediments along some parts of the beach. The data also reflect changes in beach topography due to human activity during the 2013 fall season, when private beach managers quarried ~178 m3 of sediments on the emerged beach near the shoreline to accumulate them landwards. The results show that drones can be used for regular beach monitoring activities, and that they can provide new insights into the processes related to natural and/or human-related topographic beach changes. © 2016 Springer-Verlag Berlin Heidelberg

Zeppilli D.,French Research Institute for Exploitation of the Sea | Zeppilli D.,Institut Universitaire de France | Sarrazin J.,French Research Institute for Exploitation of the Sea | Leduc D.,NIWA - National Institute of Water and Atmospheric Research | And 35 more authors.
Marine Biodiversity | Year: 2015

Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research. © 2015, The Author(s).

Rovere A.,University of Genoa | Rovere A.,SEAMap srl | Vacchi M.,University of Genoa | Vacchi M.,SEAMap srl | And 5 more authors.
Environmental Earth Sciences | Year: 2011

Within the definition given by UNESCO of World Cultural and Natural Heritage, geoheritage finds its significance both as the geological or geomorphological elements of nature worthy of conservation and as habitat of threatened species of outstanding universal value from the point of view of science or conservation. Definitions, methods, and applications for the conservation and valorization of geoheritage have been proposed for various types of environments, but their application in underwater areas is seldom, if even, reported. In this study, we propose a set of definitions and methods for the evaluation of scientific and additional values in underwater environment, and we apply them in two Mediterranean areas: Sigri (Greece, Lesvos Island) and Bergeggi (Italy, Liguria region). Results show the applicability of the schemes proposed in different geological and geomorphological settings and provide tools for the evaluation of abiotic underwater heritage in the two areas. © 2010 Springer-Verlag.

Vacchi M.,University of Genoa | Vacchi M.,SEAMap srl | Rovere A.,University of Genoa | Rovere A.,SEAMap srl | And 3 more authors.
Natural Hazards and Earth System Science | Year: 2012

Due to their importance in the assessment of coastal hazards, several studies have focused on geomorphological and sedimentological field evidence of catastrophic wave impacts related to historical tsunami events. Among them, many authors used boulder fields as important indicators of past tsunamis, especially in the Mediterranean Sea. The aim of this study was to understand the mechanism of deposition of clusters of large boulders, consisting of beachrock slabs, which were found on the southern coasts of Lesvos Island (NE Aegean Sea). Methods to infer the origin of boulder deposits (tsunami vs. storm wave) are often based on hydrodynamic models even if different environmental complexities are difficult to be incorporated into numerical models. In this study, hydrodynamic equations did not provide unequivocal indication of the mechanism responsible for boulder deposition in the study area. Further analyses, ranging from geomorphologic to seismotectonic data, indicated a tsunami as the most likely cause of displacement of the boulders but still do not allow to totally exclude the extreme storm origin. Additional historical investigations (based on tsunami catalogues, historical photos and aged inhabitants interviews) indicated that the boulders are likely to have been deposited by the tsunami triggered by the 6.7 M s Chios-Karaburum earthquake of 1949 or, alternatively, by minor effects of the destructive tsunami produced by 1956's Amorgos Island earthquake. Results of this study point out that, at Mediterranean scale, to flank numerical models with the huge amount of the available historical data become a crucial tool in terms of prevention policies related to catastrophic coastal events. © 2012 Author(s). CC Attribution 3.0 License.

Casella E.,University of Genoa | Casella E.,SEAMap srl | Rovere A.,Lamont Doherty Earth Observatory | Rovere A.,Leibniz Center for Tropical Marine Ecology | And 8 more authors.
Estuarine, Coastal and Shelf Science | Year: 2014

Monitoring the impact of sea storms on coastal areas is fundamental to study beach evolution and the vulnerability of low-lying coasts to erosion and flooding. Modelling wave runup on a beach is possible, but it requires accurate topographic data and model tuning, that can be done comparing observed and modeled runup. In this study we collected aerial photos using an Unmanned Aerial Vehicle after two different swells on the same study area. We merged the point cloud obtained with photogrammetry with multibeam data, in order to obtain a complete beach topography. Then, on each set of rectified and georeferenced UAV orthophotos, we identified the maximum wave runup for both events recognizing the wet area left by the waves. We then used our topography and numerical models to simulate the wave runup and compare the model results to observed values during the two events. Our results highlight the potential of the methodology presented, which integrates UAV platforms, photogrammetry and Geographic Information Systems to provide faster and cheaper information on beach topography and geomorphology compared with traditional techniques without losing in accuracy. We use the results obtained from this technique as a topographic base for a model that calculates runup for the two swells. The observed and modeled runups are consistent, and open new directions for future research. © 2014 Elsevier Ltd.

Discover hidden collaborations