ALBERT

Description: Increased passenger safety and emission control are two of the main driving forces in the automotive industry for the development of light weight constructions. For increased strength to weight ratio, ultra-high-strength steels (UHSSs) are used in car body structures. Prediction of failure in such sheet metals is of high significance in the simulation of car crashes to avoid additional costs and fatalities. However, a disadvantage of this class of metals is a pronounced scatter in their material properties due to e.g., the manufacturing processes. In this work, a robust numerical model is developed in order to take the scatter into account in the prediction of the failure in manganese boron steel (22MnB5). To this end, the underlying material properties which determine the shapes of forming limit curves (FLCs) are obtained from experiments. A modified Marciniak–Kuczynski model is applied to determine the failure limits. By using a statistical approach, the material scatter is quantified in terms of two limiting hardening relations. Finally, the numerical solution obtained from simulations is verified experimentally. By generation of the so called forming limit bands (FLBs), the dispersion of limit strains is captured within the bounds of forming limits instead of a single FLC. In this way, the FLBs separate the whole region into safe, necking and failed zones.

Description: This study was developed to carry out a comprehensive radiological assessment of natural radioactivity for river sediment samples from Calabria, southern Italy, and to define a baseline background for the area on a radiation map. In the studied area, elevated levels of natural radionuclides are expected, due to the outcropping acidic intrusive and metamorphic rocks from which the radioactive elements derive. To identify and quantify the natural radioisotopes, ninety river sediment samples from nine selected coastal sampling points (ten samples for each point) were collected as representative of the Ionian and the Tyrrhenian coastline of Calabria. The samples were analyzed using a gamma ray spectrometer equipped with a high-purity germanium (HPGe) detector. The values of mean activity concentrations of 226Ra, 232Th and 40K measured for the studied samples are (21.3 ± 6.3) Bq kg−1, (30.3 ± 4.5) Bq kg−1 and (849 ± 79) Bq kg−1, respectively. The calculated radiological hazard indices showed average values of 63 nGy h−1 (absorbed dose rate), 0.078 mSv y−1 (effective dose outdoors), 0.111 mSv y−1 (effective dose indoors), 63 Bq kg−1 (radium equivalent), 0.35 (Hex), 0.41 (Hin), 0.50 (activity concentration index) and 458 µSv y−1 (Annual Gonadal Equivalent Dose, AGED). In order to delineate the spatial distribution of natural radionuclides on the radiological map and to identify the areas with low, medium and high radioactivity values, the Surfer 10 software was employed. Finally, the multivariate statistical analysis was performed to deduce the interdependency and any existing relationships between the radiological indices and the concentrations of the radionuclides. The results of this study, also compared with values of other locations of the Italian Peninsula characterized by similar local geological conditions, can be used as a baseline for future investigations about radioactivity background in the investigated area.

Description: High-resolution images of Mars from National Aeronautics and Space Administration (NASA) rovers revealed mm-size loose haematite spherulitic deposits (nicknamed “blueberries”) similar to terrestrial iron-ooids, for which both abiotic and biotic genetic hypotheses have been proposed. Understanding the formation mechanism of these haematite spherules can thus improve our knowledge on the possible geologic evolution and links to life development on Mars. Here, we show that shape, size, fabric and mineralogical composition of the Martian spherules share similarities with corresponding iron spherules currently forming on the Earth over an active submarine hydrothermal system located off Panarea Island (Aeolian Islands, Mediterranean Sea). Hydrothermal fluids associated with volcanic activity enable these terrestrial spheroidal grains to form and grow. The recent exceptional discovery of a still working iron-ooid source on the Earth provides indications that past hydrothermal activity on the Red Planet is a possible scenario to be considered as the cause of formation of these enigmatic iron grains.

Description: Submarine hydrothermal systems along active volcanic ridges and arcs are highly dynamic, responding to both oceanographic (e.g., currents, tides) and deep-seated geological forcing (e.g., magma eruption, seismicity, hydrothermalism, and crustal deformation, etc.). In particular, volcanic and hydrothermal activity may also pose profoundly negative societal impacts (tsunamis, the release of climate-relevant gases and toxic metal(loid)s). These risks are particularly significant in shallow (〈1000m) coastal environments, as demonstrated by the January 2022 submarine paroxysmal eruption by the Hunga Tonga-Hunga Ha’apai Volcano that destroyed part of the island, and the October 2011 submarine eruption of El Hierro (Canary Islands) that caused vigorous upwelling, floating lava bombs, and natural seawater acidification. Volcanic hazards may be posed by the Kolumbo submarine volcano, which is part of the subduction-related Hellenic Volcanic Arc at the intersection between the Eurasian and African tectonic plates. There, the Kolumbo submarine volcano, 7 km NE of Santorini and part of Santorini’s volcanic complex, hosts an active hydrothermal vent field (HVF) on its crater floor (~500m b.s.l.), which degasses boiling CO2–dominated fluids at high temperatures (~265°C) with a clear mantle signature. Kolumbo’s HVF hosts actively forming seafloor massive sulfide deposits with high contents of potentially toxic, volatile metal(loid)s (As, Sb, Pb, Ag, Hg, and Tl). The proximity to highly populated/tourist areas at Santorini poses significant risks. However, we have limited knowledge of the potential impacts of this type of magmatic and hydrothermal activity, including those from magmatic gases and seismicity. To better evaluate such risks the activity of the submarine system must be continuously monitored with multidisciplinary and high resolution instrumentation as part of an in-situ observatory supported by discrete sampling and measurements. This paper is a design study that describes a new long-term seafloor observatory that will be installed within the Kolumbo volcano, including cutting-edge and innovative marine-technology that integrates hyperspectral imaging, temperature sensors, a radiation spectrometer, fluid/gas samplers, and pressure gauges. These instruments will be integrated into a hazard monitoring platform aimed at identifying the precursors of potentially disastrous explosive volcanic eruptions, earthquakes, landslides of the hydrothermally weakened volcanic edifice and the release of potentially toxic elements into the water column.

Description: Published

Description: 796376

Description: 1V. Storia eruttiva

Description: 2V. Struttura e sistema di alimentazione dei vulcani

Description: 3A. Geofisica marina e osservazioni multiparametriche a fondo mare

Description: 4A. Oceanografia e clima

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: Geosphere is constantly crossed by fluid fluxes of varying flow velocity and chemical composition. The development of gas geochemistry techniques over the last 50 years allowed of gaining a significant understanding of gas accumulations, gas fluxes, and their geological sources. Although gas geochemistry is a relatively recent discipline of geochemistry, advancements over the last 2 decades in sampling, storage and analysis of gas samples have enabled gas geochemistry to emerge as a critical scientific tool for constraining processes occurring in the geosciences. Chemical and isotopic features of various gas species have provided critical information about their origin, source, migration, and accumulation in specific environments, making gas geochemistry a widely used tool in a variety of fields of geosciences, including environmental/climate problems, geohazards, origin and evolution of rocks, as well as biogeochemical processes involving microbial activity. Due to the economic relevance of hydrocarbons and hydrothermal gases, they have been investigated more intensively than other gas types since very early time. Additionally, advances in our understanding of unconventional gases such as shale and tight gas in recent decades, represent new applications for these gas-related approaches. Over the last half-century, scientists in the field of gas geochemistry have exchanged their findings/experiments at major international scientific conferences organized by the International Conference on Gas Geochemistry (ICGG), the Geochemical Society, the American Geophysical Union (AGU), the European Geosciences Union (EGU), the American Association of Petroleum Geologists (AAPG), and the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI). Numerous applications of gas geochemistry in geology and the environment have been studied in recent years, and the present trend confirms that Earth and Environmental Sciences are the most promising domains for gas geochemistry applications. It is worth noting that advances in our understanding of noble/rare gas geochemistry are more closely tied to technology achievements than to fundamental geological knowledge. The current Research Topic has been devoted of compiling the most recent and pertinent experiences in the various domains of gas geochemistry. 23 papers presented but not limited in the 2019 ICGG meeting in Sicily have been accepted for publication. Hereby it is useful to report the list of published papers by date of publications and a keyword at the end in parentheses able to roughly identify the basic field of interest. In particular the paper by: (1) Qin et al. reported about Genetic Types, Distribution Patterns and Enrichment Mechanisms of Helium in China’s Petroliferous Basins (raw materials) (2) Xia et al. reported about The Characteristics of Organic Carbon in the Offshore Sediments Surrounding the Leizhou Peninsula, China (hydrocarbons) (3) Xiaobo et al. reported about Differences on Geochemical Characteristics and Their Implicating Significances of Nitrogen in Coal-Derived Gas and Oil-typed Gas in China (hydrocarbons) (4) Wu et al. reported about Inversion Characteristics of Hydrocarbon Gases Carbon Isotopes Varying With Temperature and Implications for Shale Exploration (hydrocarbons) (5) Longo et al. reported about Black Sea Methane Flares From the Seafloor: Tracking Outgassing by Using Passive Acoustics (hydrocarbons) (6) Nicula et al. reported about Geochemical Features of the Thermal and Mineral Waters From the Apuseni Mountains (Romania) (geothermics) (7) Melián et al. reported about Insights from Fumarole Gas Geochemistry on the Recent Volcanic Unrest of Pico do Fogo, Cape Verde (volcanic risk) (8) Nguyễn et al. reported about Radioactive Thoron 220Rn Exhalation From Unfired Mud Building Material Into Room Air of Earthen Dwellings (radioprotection in living environment) (9) Wang et al. reported about Potential Production of Carbon Gases and Their Responses to Paleoclimate Conditions: An Example From Xiaolongtan Basin, Southeast Tibetan Plateau (hydrocarbons) (10) Chen et al. reported about Factors Controlling Natural Gas Accumulation in the Southern Margin of Junggar Basin and Potential Exploration Targets (hydrocarbon) (11) Liang et al. reported about Preliminary Experimental Study of Methane Adsorption Capacity in Shale After Brittle Deformation Under Uniaxial Compression (hydrocarbons) (12) Ni et al. reported about Geochemical Comparison of the Deep Gases From the Sichuan and Tarim Basins, China (hydrocarbons) (13) Daskalopoulou et al. reported about Insight Into Hartoušov Mofette, Czech Republic: Tales by the Fluids (tectonophysics) (14) Gao et al. reported about Characteristics of Organic Matter and Biomarkers in Core Sediments From the Offshore Area of Leizhou Peninsula, South China Sea (hydrocarbons) (15) Cao et al. reported about The Paleoclimate Significance of the δ13C Composition of Individual Hydrocarbon Compounds in the Maoming Oil Shales, China (hydrocarbons) (16) Zhang et al. reported about Geochemical Characteristics of Gas and Flowback Water in Lake Facies Shale: A Case Study From the Junggar Basin, China (hydrocarbons) (17) Sun et al. reported about Soil Degassing From the Xianshuihe–Xiaojiang Fault System at the Eastern Boundary of the Chuan–Dian Rhombic Block, Southwest China (tectonophysics) (18) Xiaowei et al. reported about Catalytic Hydrogenation of Post-Mature Hydrocarbon Source Rocks Under Deep- Derived Fluids: An Example of Early Cambrian Yurtus Formation, Tarim Basin, NW China (hydrocarbons) (19) Fu et al. reported about An Automatic System for Continuous Monitoring and Sampling of Groundwater Geochemistry in Earthquake-Prone Regions of SW Taiwan (tectonophysics) (20) Kim et al. reported about Short-Term Monitoring of Geogenic Soil CO2 Flux in a Non-Volcanic and Seismically Inactive Emission Site, South Korea (tectonophysics) (21) Sano et al. reported about Groundwater Anomaly Related to CCS-CO2 Injection and the 2018 Hokkaido Eastern Iburi Earthquake in Japan (carbon capture and storage) (22) Siino et al. reported about Stochastic Models for Radon Daily Time Series: Seasonality, Stationarity, and Long-Range Dependence Detection (data processing) (23) Zafrir et al. reported about The Impact of Atmospheric and Tectonic Constraints on Radon-222 and Carbon Dioxide Flow in Geological Porous Media—A Dozen-Year Research Summary (tectonophysics)

Description: Published

Description: 936733

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: JCR Journal