Caratterizzazione dell’ambiente marino dei Campi Flegrei. Risultati preliminari della campagna oceanografica RICAMAR 2013

The caldera of the Phlegraean Fields (also known as Campi Flegrei) is one of the most dangerous and populated volcanic area in the world, covering an area that comprises the western part of Naples and the Gulf of Pozzuoli. The main peculiarity of current volcanic activity is the gradual and periodic lift (positive or negative) of part of the Earth\u27s surface (bradyseism) combined, only during the positive phase, with a strong sismicity and surficial hydrotermal activity. Deformative models, calibrated using land-based measurements, highlighted the Gulf of Pozzuoli as the area with the largest deformation. Although the network of monitoring sensors on land is well developed and structured, there is a lack of sensing systems for the marine deformation. The activities of RIlievi per la Caratterizzazione dell’Ambiente MARino nel Golfo di Pozzuoli 2013 (RICAMAR2013) project - sinergically conducted by the Italian Navy\u27s Survey Vessel Ammiraglio Magnaghi , the Italian Hydrographic Office (IIM) and the Istituto Nazionale di Geofisica e Vulcanologia (INGV)- were targeted to fulfill this gap. In fact, the creation of marine observatories about the caldera\u27s phenomena will be based on the data collected during these bathymetric, magnetometric, stratigrafic and hydrologic surveys

Rapporto sull’attività 13 – 31 maggio 2013

La caldera risorgente dei Campi Flegrei è, insieme ai vulcani Somma-Vesuvio, Ischia e Procida, uno degli elementi dominanti dell’assetto geologico e morfologico dell’area napoletana. Si tratta di un sistema vulcanico ancora attivo la cui persistente attività è testimoniata dall’ultima eruzione, avvenuta nel 1538, dall’intensa attività fumarolica e idrotermale che perdura da millenni e dai frequenti eventi bradisismici, con deformazione del suolo accompagnata da sismicità e variazioni delle caratteristiche chimico-fisiche dei fluidi emessi dalle fumarole. La caldera comprende la parte occidentale della città di Napoli e si estende nel Golfo di Pozzuoli. La caratteristica principale dell’attuale attività vulcanica della caldera è il movimento lento del suolo a carattere episodico e di grande ampiezza (bradisismo), accompagnato da un’intensa e superficiale attività sismica che si verifica in generale durante la fase di sollevamento......Istituto Nazionale di Geofisica e Vulcanologia - Marina Militare ItalianaPublished6A. Monitoraggio ambientale, sicurezza e territorioope

Last century seabed morphodynamics of the Magra River estuary (Western Mediterranean Sea)

The estimation of morphological and volumetric changes of the delta system at the mouth of the Magra River is presented in this paper using bathymetric and sedimentological data. The data series were collected during several hydro-oceanographic surveys carried out from 1882 to 2014, processed following the hydrographic international standards and stored in the Italian Navy Hydrographic Institute database. In particular, bathymetric data characterized by the same standard and accuracy were collected using different devices such as sounding lines, single-beam and multi-beam acoustic system. This research compares Digital Terrain Models (DTMs), derived from highly accurate bathymetric data and covering different time scales (secular, half-century and decade) in order to assess and quantify the seabed morphodynamics in relation with the river sedimentary budget. The methodology and data exploitation consist mainly in the production of DTMs to study the elevation change, two-dimensional and three dimensional maps, cross-sections of the seabed, difference surfaces and computation of net volumes as well as an historical sedimentological map. These products are also an useful contribution to the aim of EU RISC-KIT Project. The results of the analysis highlight changes in the geometry of the Magra River mouth, of the coastal profile and bottom features primarily due to variations of the sedimentary budget and secondarily to wave dynamics. This behaviour is characterized by evident river mouth and coastal retreat, beach erosion and sediment bars decay and net accretion under periods of high river sediment discharge and elongate bar formation during relatively fair conditions. In the last century the main change is constituted by the disappearance of the typical constructive seabed delta morphology and the transformation into the current small estuary, with microtidal condition. This small estuary has an upper sector where river processes, sediments and bedforms dominate, a lower sector near the mouth, where wave and tidal processes and marine sediments dominate, and a middle sector, where tidal currents dominate and both river and marine sediments are present

Rapporto sulle attivita’ oceanografiche, geochimiche, geologiche, geofisiche e di campionamento durante la crociera PANA13 con ITS Magnaghi : Panarea, I.Eolie, Tirreno S.Orientale, 2013-06-02- 2013-06-08.

Vengono presentate le attivita\u27 ed i risultati preliminari della crociera PANA13 ( 2013-06-02- 2013-06-08)con ITS Magnaghi . Le attivita’ principali previste erano la acquisizione di dati geochimici, geologici, geofisici e di campionamento acque e sedimento nella zona di Panarea, Isole Eolie, Tirreno Centro Meridionale. Si sono anche effettuate misure di DIC e flussi alla interfaccia acqua/sedimento con Camera bentica, per lo studio del problema della acidificazione dell’Oceano e dei processi relativi alla CO2

New geological, geophysical and biological insights on the hydrothermal system of the Panarea – Basiluzzo Volcanic complex (Aeolian Islands, Tyrrhenian Sea)

Since the exhalative crisis of 2002 cruises were carried out to investigate morphology, magnetic and gravity fields, fluid escape, plume anomalies, biological and microbiological activity, benthic fluxes, early diagenesis, mineralogy and geochemistry of water and sediments of the hydrothermal system of Panarea. The volcanic complex was mapped by multibeam, including backscatter analysis, and magnetometric surveys were done to detect low magnetization in areas with hydrothermal activity, i.e., vents, sulphide deposits, chimney fields. CTD by ship and on ROV detected acidic plumes at bottom (minimum pH value 6.5) and mid depths. An Automatic Benthic Chamber was deployed on a terrace (40m) and in depressions with gas-charged and hydrothermally altered sediments (80m). At the 40m site, strong releases of Dissolved Inorganic Carbon (DIC) and Fe, Mn, Zn (75.7, 2.0, 2.9, 3.4 µmol m -2 day -1 ) were found. Average decrease of pH in the chamber was ~4 units day -1 with a H + benthic flux of 0.32 µmol m -2 day -1 ). DIC values of seawater had average 2.3, increasing to 3.1 on degassing vents, while 7.5 µmol was measured on top of a bubbling core. ROV dives explored and sampled several sites; active chimneys (black, red crusts and yellowish-orange precipitates at top) were recovered on the SE flanks of Basiluzzo; pH value of 5 was measured aboard on sediments. XRD and XRF data on the external crust showed Fe-Mn oxyhydroxides, including goethite and opal, with Co, Ce, Sr, Zn and Cu enrichments, whereas the inner part are depleted of Fe, Mn and other metals, mostly under detection limits. SEM imagery shows porous filamentous minerals, that are probably bacterial in origin. Dives to SW discovered fields of partially or totally relict chimneys at the same depth (~200m). Chimneys are present on the edges of slope failures and settled on areas of relative lower positive magnetic anomaly, indicating possible shallow depth level of hydrothermal alteration. Reddish crusts and sediments, and acid, gas boiling water (pH 5.5) were cored at 90 m depth upslope of the \u27active\u27 chimneys; upslope from the \u27relict\u27 chimney\u27s fields, oxized-normal sediments were found. Biological investigations on the sediments revealed a community strongly dominated by the amphipod Ampelisca ledoyeri (43.8 % of the total abundance), probably dwelling in the tube-patches. Rare species were detected on the chimney\u27s samples. The phylogenetic diversity of microbial communities in the precipitates collected on chimneys and on Bottaro vent was analyzed by bacterial and archaeal 16S rDNA clone libraries, showing a dominance of sulfur-oxidazing epsilon and gamma proteobacteria. Very interesting groups of archaea were revealed including methanotrophic Thermoplasmatales and members of SM1 candidate division. Overall prokaryotic diversity was found similar to that of deep sea hydrothermal vents and other sulfidic habitats. White microbial mats were found in an area S of Panarea, on a N-S oriented fracture