Pyroclastic lumps: quick diapiric structures off the Naples Bay, Italy. European Geophysical Society (EGS), 25th General Assembly, Millenium Conference on Earth, Planetary & Solar Systems. Nice (France) 25-29 Aprii 2000.

Sacchi M., D'Argenio B., Morra V., Petrazzuoli S., Àiello G., Budillon F., Samacchiaro G. and Tonielli R., 2000. Pyroclastic lumps: quick diapiric structures off the Naples Bay, Italy. European Geophysical Society (EGS), 25th General Assembly, Millenium Conference on Earth, Planetary & Solar Systems. Nice (France) 25-29 Aprii 2000

Early cementation and accommodation space dictate the evolution of an overstepping barrier system during the Holocene

The morphology and stratigraphic features of a well-preserved drowned barrier system, located on the western coast of Sardinia (Mediterranean Sea), are presented here. The barriers were mapped using a multibeam echosounder. The Digital Terrain Model of the seabed revealed five sub-parallel barriers in a depth range of 18\u201337 m, with a distance of ~ 300 m between each single barrier. Direct inspection by scuba diving, revealed that the barriers consist of beachrocks, topped by seagrass meadows growing on a biogenic hardground. The inner-most barrier is limited landward by a steep cliff, 10 m high, bordering the back-barrier area. About 200 km of seismic lines were collected along the barrier system using a 0.4\u20131.0 kJ sparker source and a 3.5 kHz Chirp Subbottom profiler. The seismic data, calibrated with vibrocores, allowed us to recognize the subaerial topographic surface of the last glacial maximum as well as several seismic units interpreted as the Pliocene marine sediments, the pre-Holocene deposits and the Holocene barrier\u2013lagoon complex composed of shoreface, barrier, lagoonal/deltaic and beach deposits. Despite the relatively high seabed gradient (0.3\ub0\u20130.4\ub0) and the relatively low rate of sea-level rise (10\u201315 mm y 12 1), the barriers were well preserved due to the early diagenetic processes which led to a rapid cementation with the formation of beachrocks, and the subsequent overstepping with the rise of the sea level. The development of the overstepping barrier system is strictly related to the antecedent subaerial topography which is, in turn, related to the tectonic setting of the area. The Pliocene seismic unit was lowered by a direct fault at the entrance of the gulf forming a depression filled by sediments. The overstepping barrier system developed following the increase of the seabed gradient and was limited landward by the above-mentioned depression which increased the accommodation space. Following the sea-level rise and the barrier formation, this depression was filled by lagoonal sediments, washover fans and sediments coming from the rivers. The age model of barrier evolution, based on previous sea-level-rise curves during the Holocene, supported by radiocarbon data, highlighted that the whole system evolved over a time period of 1 ka; while the time elapsed from this formation to the drowning of single barriers was estimated to be in the order of magnitude of centuries. Scenarios of short-term evolution of modern barrier\u2013lagoon systems of the adjacent coastal sector, under conditions of accelerated sea-level rise, according to Church et al. (2013) (2013 IPCC report) and Rahmstorf (2007) projections, were elaborated. The study of this ancient analogue suggests that the processes of adaptation of coastal systems to the rising sea level would require times evaluable from centuries to millennia

Biogenic sediments from coastal ecosystems to beach-dune systems: implications for the adaptation of mixed and carbonate beaches to future sea level rise

Coastal ecosystems produce and store carbonate particles, which play a significant role in the carbonate dynamics of coastal areas and may contribute to the sediment budget of adjacent beaches. In the nearshore seabed of temperate zones (e.g. Mediterranean Sea and South Australia), marine biogenic carbonates are mainly produced inside sea-grass meadows. This study quantifies the contribution of biogenic sediments, mainly produced in Posidonia oceanica seagrass meadows and secondarily in photophilic algal communities, to the sediment budget of a Mediterranean beach-dune system (San Giovanni beach, western Sardinia, western Mediterranean Sea). A set of geophysical, petrographic and sedimentological data was used to estimate the sediment volume and composition of the beach-dune system as a whole. The San Giovanni beach-dune system contains 3797000 +/- 404000 t of sediment, 83% (3137000 +/- 404000 t) of which is located in the coastal wedge, 16% (619000 +/- 88000 t) in the dune fields and 1% (41000 +/- 15000 t) in the sub-aerial beach. The sediments are composed of mixed modern bioclastic and relict bioclastic and non-bioclastic grains from various sources. The system receives a large input of modern bioclastic grains, mainly composed of rhodophytes, molluscs and bryozoans, which derive from sediment production of present-day carbonate factories, particularly P. oceanica seagrass meadows. Radiocarbon dating of modern bioclastic grains indicated that they were produced during the last 4.37 kyr. This value was used to estimate the longterm deposition rates of modern bioclastic sediments in the various beach compartments. The total deposition rate of modern bioclastic grains is 46000 +/- 5000 t century 1, mainly deposited in the coastal wedge (39000 +/- 4000 t century(-1)) and dunes (7000 +/- 1000 t century(-1)), and 46 000 t represents similar to 1.2% of the total beach-dune sediment mass. Carbonate production from coastal ecosystems was estimated to be 132000/307000 t century(-1), 28% (15%/34 %) of which is transported to the beach-dune system, thus significantly contributing to the beach sediment budget.The contribution to the beach sediment budget represents a further ecosystem service, which our data can help quantify, provided by P. oceanica. The value of this sediment-supply service is in addition to the other important ecological services provided by seagrass meadows. The dependence of the beach sediment budget on carbonate production associated with coastal ecosystems has several implications for the adaptation of mixed and carbonate beaches to the loss of seagrass meadows due to local impacts and the changes expected to occur over the next few decades in coastal ecosystems following sea level rise

Open-slope, translational submarine landslide in a tectonically active volcanic continental margin (Licosa submarine landslide, southern Tyrrhenian Sea)

The southern Tyrrhenian continental margin is the product of Pliocene-Recent back-arc extension. An area of approximately 30 km of gentle (about 1.5°) lower slope of the last glacial outer shelf sedimentary wedge in water depths of between 200 and 300 m failed between 14 and 11 ka BP. We approached the landslide by multibeam and sub-bottom profiler surveying, high-resolution multichannel seismics, and coring for stratigraphic and geotechnical purposes. With regard to a slope-stability analysis, we carried out an assessment of the stratigraphic and structural setting of the area of the Licosa landslide. This analysis revealed that the landslide detached along a marker bed that was composed of the tephra layer Y-5 (c. 39 ka). Several previously unknown geological characteristics of the area are likely to have affected the slope stability. These are the basal erosion of the slope in the Licosa Channel, a high sedimentation rate in the sedimentary wedge, earthquake shaking, the volcanic ash nature of the detachment surface, subsurface gas/fluid migration, and lateral porewater flow from the depocentre of wedge to the base of the slope along the high-permeability ash layers. A newly discovered prominent structural discontinuity is identified as the fault whose activity may have triggered the landslide

Seabed mapping in the Pelagie Islands marine protected area (Sicily Channel, southern Mediterranean) using Remote Sensing Object Based Image Analysis (RSOBIA)

In this paper we present the seabed maps of the shallow-water areas of Lampedusa and Linosa, belonging to the Pelagie Islands Marine Protected Area. Two surveys were carried out (“Lampedusa 2015” and “Linosa 2016”) to collect bathymetric and acoustic backscatter data through the use of a Reson SeaBat 7125 high-resolution multibeam system. Ground-truth data, in the form of grab samples and diver video-observations, were also collected during both surveys. Sediment samples were analyzed for grain size, while video images were analyzed and described revealing the acoustic seabed and other bio-physical characteristics. A map of seabed classification, including sediment types and seagrass distribution, was produced using the tool Remote Sensing Object Based Image Analysis (RSOBIA) by integrating information derived from backscatter data and bathy-morphological features, validated by ground-truth data. This allows to create a first seabed maps (i.e. benthoscape classification), of Lampedusa and Linosa, at scale 1:20 000 and 1:32 000, respectively, that will be checked and implemented through further surveys. The results point out a very rich and largely variable marine ecosystem on the seabed surrounding the two islands, with the occurrence of priority habitats, and will be of support for a more comprehensive maritime spatial planning of the Marine Protected Area

Monitoraggio integrato di un'area marino-costiera: la foce del fiume Volturno (Mar Tirreno centrale)

Vengono presentati i risultati dell’attività di monitoraggio svolta nel corso del progetto PONa3_00363 I-AMICA (Infrastruttura di Alta tecnologia per il Monitoraggio Integrato Climatico-Ambientale; www.i-amica.it/i-amica/), nell’ambito delle attività relative all’Obiettivo Realizzativo 4.4 (Processi di interfaccia biosfera-idrosfera e funzionalità degli ecosistemi costieri). L’attività, che ha avuto come scopo l’acquisizione di conoscenze avanzate sulle dinamiche e/o variazioni nel tempo degli ecosistemi marino-costieri in relazione ai processi fisici, chimici e biologici che caratterizzano il loro habitat, si è sviluppata attraverso la sperimentazione di nuove metodologie di monitoraggio in relazione alle specifiche caratteristiche dell’area marino-costiera prospiciente la foce del fiume Volturno (Golfo di Gaeta). In particolare, oltre che sulle tecniche di monitoraggio classiche, lo studio si è principalmente focalizzato sulla acquisizione ed interpretazione di dati ambientali sia in colonna d’acqua che nei sedimenti a fondo mare e sulla identificazione di specie e/o associazioni di specie significative (bio-indicatori) da un punto di vista ambientale ed indicative dello stato di salute del sistema costiero. Poiché il sistema costiero rappresenta una struttura naturale complessa e delicata, la cui evoluzione è il risultato di delicati equilibri fisici, chimici e biologici, fortemente condizionabili dagli interventi antropici, l’attività di monitoraggio è stata integrata da studi sulla variazione della linea di costa, da studi sismostratigrafici della piana deltizia, sedimentologici e morfo-batimetrici dei fondali.Published1-714A. Oceanografia e climaJCR Journa

Rapporto di Fine Campagna Magic_IAMC1211

Campagna oceanografica MAGIC IAMC 1211 N/O URANIA. Rapporto di fine campagna 27/12/11-04/01/1

Relazione finale della Campagna Oceanografica "Linosa"

Il presente documento descrive le attività svolte durante la Campagna Oceanografica “Linosa” dall’Istituto per l’Ambiente Marino Costiero IAMC-CNR di Napoli relativo alla Convenzione per la “Realizzazione di Attività di Ricerca e Monitoraggio nell’Area Marina Protetta “Isole Pelagie” (Prot. N° 0013232 del 28/12/2015)” tra il Comune di Lampedusa e Linosa, Ente Gestore dell’Area Marina Protetta – AMP “Isole Pelagie”, e l’IAMC di Napoli. La convenzione è stata stipulata a seguito della collaborazione nata con l’AMP e l’IAMC per il monitoraggio dello stato di conservazione della Posidonia oceanica dell’isola di Lampedusa (Di Martino et al. 2015; Tonielli et al. 2016) ed è nata per lo svolgimento degli studi morfo-batimetrici dei fondali nell’area marino costiera dell’isola di Linosa, nei settori di competenza dell’AMP, finalizzati in particolare alla mappatura dei fondali per la definizione delle biocenosi prioritarie (Posidonia oceanica e coralligeno)

Rapporto di Fine Campagna Magic_IAMC0610

Campagna oceanografica MAGIC IAMC 0610, N/O MARIA GRAZIA. Rapporto di fine campagna 07/06/10-01/07/1