http://hdl.handle.net/2122/110 Ricerca nel canale cerca http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/5998 Titolo: Installazione di un mini-sistema DAQ con idrofono su fondale marino in acque basse<br/><br/>Autori: Guardato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Orazi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Caputo, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Buonocunto, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia http://hdl.handle.net/2122/5956 Titolo: BFM-SI: A new implementation of the biogeochemical flux model in sea ice<br/><br/>Autori: Tedesco, Letizia; CMCC; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia<br/><br/>Abstract: This work describes a novel implementation of the Biogeochemical Flux Model (BFM) in a sea ice system (BFMSI). The chosen representative groups of the sea ice food web rely on the same dynamics as the BFM. The main differences between BFM and BFMSI stand in the type and number of functional groups, in the parameters assigned to several physiological and ecological processes and in the dimensional size classes they represent. The differential equations of BFMSI are written here according to the nomenclature associated to the new sea ice state variables. At the boundaries, the sea ice system is also coupled to the atmosphere and to the ocean through the exchange of organic and inorganic matter. This is done by computing the entrapment of particulate and dissolved matter and gases when sea ice grows and release to the ocean when sea ice melts to ensure mass conservation. The implementation of the BFM in sea ice and the coupling structure in General Circulation Models will add a new component that may provide new adequate estimate of the role and importance of sea ice biogeochemistry in the global carbon cycle. http://hdl.handle.net/2122/5928 Titolo: Deformation of 125 ka marine terraces: tectonic implications<br/><br/>Autori: Bordoni, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Valensise, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia<br/><br/>Curatori: Stewart, I. S.; Brunel University, London; Vita-Finzi, C.; University College London<br/><br/>Abstract: In peninsular Italy, marine terraces and shorelines created during oxygen- isotope substage 5e, known historically as the Tyrrhenian highstand, provide a reliable and homogeneous datum of vertical motions during the past 125,000 years. Published accounts of 121 locations on the Tyrrhenian inner edge were reinterpreted and used to calculate both local and regional uplift rates. The data show arching of southern Italy between the Tyrrhenian and the Adriatic coasts and of the Calabrian Arc between the Sangineto and the Longi-Taormina tectonic lineaments at rates of up to 1.2 mm/yr for the past 125 ka. They also suggest that the present configuration of the southern Apennines is the product of post-Early Pleistocene regional uplift superimposed on Tortonian to Early Pleistocene thrusting. Uplift patterns are characterised by different wavelength in different geodynamic settings, suggesting a close link with the depth of the causative tectonic sources. http://hdl.handle.net/2122/5891 Titolo: Radar systems for Glaciology<br/><br/>Autori: Zirizzotti, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Urbini, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Cafarella, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Baskaradas, J. A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia<br/><br/>Curatori: Kouemou, G.<br/><br/>Abstract: This chapter deals with radar systems, measurements and instrumentationemployed to study the internal core and bedrock of ice sheets in glaciology. The Earth's ice sheets are in Greenland and Antarctica. They cover about 10% of the land surface of the planet. The total accumulated ice comprises 90% of the global fresh water reserve. These ice sheets, associated with the ocean environment, provide a major heat sink which significantly modulates climate.Glaciology studies aim to understand the various process involved in the flow (dynamics), thermodynamics, and long-term behaviour of ice sheets.Studies of large ice masses are conducted in adverse environmental conditions (extreme cold, long periods of darkness). The development of remote sensing techniques have played an important role in obtaining useful results. The most widely used techniques are radar systems, employed sincethe 1950s in response to a need to provide a rapid and accurate method of measuring ice thickness. Year by year, polar research has become increasingly important because of global warming. Moreover, the discovery ofnumerous subglacial lake areas (water entrapped beneath the ice sheets) hasattracted scientific interest in the possible existence of water circulationbetween lakes or beneath the ice (Kapitsa et al., 2006; Wingham et al., 2006; Bell et al., 2007). Recent studies in radar signal shape and amplitude could provide evidence of water circulation below the ice (Carter 2007, Oswald and Gogineni 2008).In this chapter the radar systems employed in glaciology, radio echo sounding (RES), are briefly described with some interesting results. RES are active remote sensing systems that utilize electromagnetic waves that penetrate the ice. They are used to obtain information about the electromagnetic properties of different interfaces (for example rock-ice, ice-water, seawater-ice) that reflect the incoming signal back to the radar.RES systems are characterized by a high energy (peak power from 10 W to 10 KW) variable transmitted pulse width (about from 0.5 ns to several microseconds) in order to investigate bedrock characteristics even in the thickest zones of the ice sheets (4755 m is the deepest ice thickness measured in Antarctica using a RES system). Changing the pulse length or the transmitted signal frequencies it is possible to investigate particular ice sheet details with different resolution. Long pulses allows transmission of higher power than short pulses, penetrating the thickest parts of the icesheets but, as a consequence, resolution decreases. For example, the GPR system, commonly used in geophysics for rock, soil, ice, fresh water, pavement and structure characterization, employs a very short transmitted pulse (0.5 ns to 10 ns) that allow detailing of the shallow parts of an ice sheet (100-200 m in depth) (Reynolds 1997). Consequently, in recent years,GPR systems are also employed by explorers to find hidden crevasses on glaciers for safety. RES surveys have been widely employed in Antarctic ice sheet exploration andthey are still an indispensable tool for mapping bedrock morphologies and properties of the last unexplored continent on Earth. The advantage of using these remote sensing techniques is that they allow large areas to be covered, in good detail and in short times using platforms like aeroplanesand surface vehicles. http://hdl.handle.net/2122/5888 Titolo: La radiopropagazione nei ghiacciai<br/><br/>Autori: Bianchi, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Sciacca, U.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia<br/><br/>Abstract: Da alcuni anni l'INGV sta partecipando a progetti di ricerca nel campo della radioglaciologia, cioè lo studio dei ghiacciai tramite sistemi radar conosciuti anche come Radio Echo Sounding. Gli esiti del lavoro svolto in Istituto e i risultati delle campagne hanno portato alla pubblicazione di alcuni lavori, la formulazione dei quali ha richiesto lo svolgimento preventivo di considerazioni teoriche e l'approntamento di procedure di calibrazione. Queste considerazioni sono raccolte nel presente lavoro. http://hdl.handle.net/2122/5842 Titolo: Marine climate change and environmental indicators from the Marine Core Service<br/><br/>Autori: Coppini, Giovanni; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Lyubartsev, Vladyslav; Centro EuroMediterraneo per i Cambiamenti Climatici; Pinardi, Nadia; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Fratianni, Claudia; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Tonani, Marina; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Adani, Mario; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Oddo, Paolo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Dobricic, Srdjan; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Marullo, Salvatore; ENEA; Loewe, Peter; BSH; Santoleri, Rosalia; CNR-ISAC; Colella, Simone; CNR-ISAC; Volpe, Gianluca; CNR-ISAC<br/><br/>Curatori: ENVIROINFO<br/><br/>Abstract: In the framework of the Mediterranean Operational Oceanography Network (MOON, http://www.moon-oceanforecasting.eu) The Mediterranean Forecasting System (Pinardi et al., 2003) has started the design and development of services that include the routine production of environmental and climate indicators. A process of identifying user requirements has been started in collaboration with European Environment Agency and the indicators definition and implementation aim to take user requirements into account. The indicators are extensively used by EEA (EEA web page on indicators: http://themes.eea.europa.eu/indicators/). INGV has carried out an analysis on the possible improvements of existing indicators in use by EEA and on the development of new indicators based on Marine Core Services (MCS) products. The list of indicators includes: Temperature, Chlorophyll-a (from ocean colour), Ocean Currents and Transport, Salinity, Transparency, Sea Level, Sea Ice and Density. A critical analysis has been carried out to identify the relevance of the above-mentioned indicators for EU policies, their spatial and temporal coverage, their accuracy and their availability (Coppini et al., 2008). INGV in collaboration with CNR-ISAC are directly involved on the development of the indicators in the Mediterranean region and European Seas region the Temperature and Chlorophyll-a (Chl-a) products are the most suitable for an indicator development test phase. In particular the OO Chl-a product, deduced from satellite data, is able to contribute to the further development of the EEA Chl-a indicator on eutrohpication that is based on in-situ measurements (CSI023). For this indicator a development phase has been undertaken in 2008 and 2009 within the European Topic Center for Water (ETC-W) for EEA. The temperature indicators, developed with the support of MyOcean and Operational Oceanography community, consist of long time series (1870-Today) of SST anomaly able to describe ocean temperature increase due to climate change in the European Seas and on SST trends map of the last 25 years for the European Seas. These last two indicators have been included in the last 2008 EEA report on Impacts of Climate change in the European Seas (http://www.eea.europa.eu/publications/eea_report_2008_4). Moreover MFS re-analysis have been produced for the Mediterranean Sea and it consists of daily output of MFS-OPA hydrodinamic model (1/16 of degree horizontal resolution) that assimilates all available in situ and satellite observation for 1985 to 2007. This reanalysis product is used to detect temperature anomalies over the last 20 years in the coastal zone that could be related with environmental stresses. In addition to that we have also identified a Density indicator that appears relevant for the ecosystem health assessment in the coastal waters. http://hdl.handle.net/2122/5744 Titolo: Modelling approach to the assessment of biogenic fluxes at a selected Ross Sea site, Antarctica<br/><br/>Autori: Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Coluccelli, A.; UniPoliMa; Ravaioli, F.; CNR-ISMAR; Giglio, F.; CNR-ISMAR; Langone, L.; CNR-ISMAR; Azzaro, M.; CNR-IAMC; Azzaro, F.; CNR-IAMC; La Ferla, R.; CNR-IAMC; Catalano, G.; CNR-ISMAR; Cozzi, S.; CNR-ISMAR<br/><br/>Abstract: Several biogeochemical data have been collected in the last 10 years of Italian activity in Antarctica (ABIOCLEAR, ROSSMIZE, BIOSESO-I/II). A comprehensive 1-D biogeochemical model was implemented as a tool to link observations with processes and to investigate the mechanisms that regulate the flux of biogenic material through the water column. The model is ideally located at station B (175° E–74° S) and was set up to reproduce the seasonal cycle of phytoplankton and organic matter fluxes as forced by the dominant water column physics over the period 1990–2001. Austral spring-summer bloom conditions are assessed by comparing simulated nutrient drawdown, primary production rates, bacterial respiration and biomass with the available observations. The simulated biogenic fluxes of carbon, nitrogen and silica have been compared with the fluxes derived from sediment traps data. The model reproduces the observed magnitude of the biogenic fluxes, especially those found in the bottom sediment trap, but the peaks are markedly delayed in time. Sensitivity experiments have shown that the characterization of detritus, the choice of the sinking velocity and the degradation rates are crucial for the timing and magnitude of the vertical fluxes. An increase of velocity leads to a shift towards observation but also to an overestimation of the deposition flux which can be counteracted by higher bacterial remineralization rates. Model results suggest that the timing of the observed fluxes depends first and foremost on the timing of surface production and on a combination of size-distribution and quality of the autochtonous biogenic material. It is hypothesized that the bottom sediment trap collects material originated from the rapid sinking of freshly-produced particles and also from the previous year's production period. http://hdl.handle.net/2122/5743 Titolo: An enhanced sea-ice thermodynamic model applied to the Baltic sea<br/><br/>Autori: Tedesco, L.; CMCC; Vichi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Haapala, J.; Finnish Institute of Marine Research; Stipa, T.; Finnish Institute of Marine Research<br/><br/>Abstract: A refined Semtner 0-layer sea-ice model (ESIM1) is presented and applied to the Baltic landfast sea-ice. The physical model is capable of simulating seasonal changes of snow and ice thickness. Particular attention is paid to reproducing the snow-ice and the super-imposed-ice formation which play important roles in the total mass balance of the Baltic sea-ice. The model prognostic variables include all kinds of ice and snow layers that may be present during a Baltic landfast ice season and, in general, in every coastal area of an ice-covered ocean. The assessment of the model capabilities was done for 1979–1993 for four different stations in the Baltic Sea. A sensitivity test stresses the relevant role of some of the physical parameters, such as the oceanic heat flux, while a scenario analysis highlights the robustness of the model to perturbed physical forcing. Our results show that one of the key variables in modelling sea-ice thermodynamics is the snow layer and its metamorphism, and including the meteoric ice dynamics into a sea ice model is relevant to properly simulate any ice season, also in view of climate change scenarios http://hdl.handle.net/2122/5474 Titolo: Evoluzione geomorfologica di un'area suburbana di Castronuovo S. Andrea (PZ) ed incidenza delle piogge su alcuni movimenti di massa<br/><br/>Autori: D'Ecclesiis, G.; Università della Basilicata; Grassi, D.; Università della Basilicata; Merenda, L.; CNR-IRPI; Polemio, M.; CNR-IRPI; Sdao, F.; Università della Basilicata<br/><br/>Abstract: This work deals with the results obtained from geomorphological and hydrological investigation conducted in order to point out the complex geomorphological evolution related to a large part of the Castronuovo S. Andrea (Pz) territory, to identify the landslide typology of two different mass movements under investigation, as well as the influence caused by the rainfall. The landslide under study occurred on two opposite slopes of the low valley of torrent Mastro Ciardi, characterized by the same stratigraphic-structural, hydrogeological and geotechnical environment. The first slope e can be ascribed to a displacement of a first detachment, while the other one brat least 700io can be referred to a rimobilization phenomenon; both landslides, to a variable extent, have been influenced by tectonic joints following two different directions: NE - SW and WNW - ESE.As far as the last 40 years are concerned, the morphological evolution of the areas under study has been obtained resorting to analyses, even comparative, of aerial photos at different generation; the relationship between rainfall and landslide has been identified in an empirical way through special models. http://hdl.handle.net/2122/5383 Titolo: Il contributo dei pozzi perforati dalla Regione Lombardia alla conoscenza del Pleistocene lombardo<br/><br/>Autori: Scardia, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Muttoni, G.; Università di Milano<br/><br/>Abstract: Facies analysis applied to several up to 220-m-deep cores, taken by Regione Lombardia in the central-northern Po Plain, allowed to recognize an overall regressive sequence consisting of cyclotemic shallow marine and fluvial-deltaic deposits overlain by distal to proximal braidplain sediments. Magnetostratigraphy, coupled with calcareous nannoplankton biostratigraphy, was used to date marine and fluvial-deltaic sediments to the early Pleistocene and continental sediments to the middle–late Pleistocene. Sediment accumulation rates were of ~0.3-0.4 mm/yr in the early Pleistocene, whereas an overall reduction in sediment accumulation rates to ~0.06-0.08 mm/yr, associated to relevant unconformities, characterized the middle-late Pleistocene.Stratigraphic evidences from petrographic, sedimentologic and palynologic analyses highlight in the Regione Lombardia cores a drastic reorganization of vegetational, fluvial, and Alpine drainage patterns, associated to a sequence boundary termed the “R surface”. The “R surface”, seismically traceable across the Po Plain subsurface, was constrained magnetostratigraphically to the first prominent Pleistocene glacio-eustatic lowstand of marine isotope stage (MIS) 22 at 0.87 Ma at the end of the Mid-Pleistocene Revolution, when climate worsened globally and locally caused the onset of the first major Pleistocene glaciation in the Alps.Most marine deposits in the cores lie above sea level highstands of corresponding age, suggesting that they have been uplifted. In order to estimate the observed rock uplift, sediments were back-stripped to elevations at times of deposition (expressed in meters above current sea level) by applying a simple Airy compensation model. The correlation of the isostatically corrected sedimentary facies to a glacio-eustatic reference curve obtained from classic oxygen isotope studies highlights a positive elevation mismatch (rock uplift) in the range of 70-120 m, which occurred after the onset of the major Pleistocene glacial-interglacial cycles at rates of at least 0.15-0.09 mm/yr. Although the driving forces of the observed rock uplift cannot be unambiguously identified, but its timing of onset after the beginning of the major Pleistocene glacial-interglacial cycles and the low seismicity observed in the most of the Regione Lombardia area seem to point to an isostatic readjustment of the chain probably due to the long-term erosional removal of sediments during major Pleistocene glacial advances.