Time filter

Source Type

Blengini G.A.,Polytechnic University of Turin | Blengini G.A.,CNR Institute of Environmental Geology and Geoengineering | Di Carlo T.,Polytechnic University of Turin
Energy and Buildings | Year: 2010

A detailed Life Cycle Assessment (LCA) has been conducted on a low energy family house recently built in Northern Italy. The yearly net winter heat requirement is 10 kWh/m2, while the same unit with legal standard insulation would require 110 kWh/m2. As the building was claimed to be sustainable on the basis of its outstanding energy saving performances, an ex post LCA was set up to understand whether, and to what extent, the positive judgement could be confirmed in a life cycle perspective. The dramatic contribution of materials-related impacts emerged. The shell-embedded materials represented the highest relative contribution, but maintenance operations also played a major role. The contributions of plants, building process and transportation were minor. The important role of the recycling potential also emerged. Unlike standard buildings, where heating-related impacts overshadow the rest of the life cycle, there is no single dominating item or aspect. Rather, several of them play equally important roles. The study has confirmed that the initial goal of environmental sustainability was reached, but to a much lower extent than previously thought. In comparison to a standard house, while the winter heat requirement was reduced by a ratio of 10:1, the life cycle energy was only reduced by 2.1:1 and the carbon footprint by 2.2:1. © 2010 Elsevier B.V. All rights reserved. Source

Voltaggio M.,CNR Institute of Environmental Geology and Geoengineering
Radiation Protection Dosimetry | Year: 2012

During atmospheric thermal inversions, dew and hoarfrost concentrate gamma emitting radionuclides of the short-lived 222Rn progeny ( 214Pb and 214Bi), causing an increase in the total natural gamma background from the ground. To highlight this phenomenon, a volcanic zone of high 222Rn flux was studied during the winter season 2010-11. High-specific short-lived radon progeny activities up to 122 Bq g -1 were detected in hydrometeors forming at the earth's surface (ESHs), corresponding to a mean increase of up to 17 % of the normal gamma background value. A theoretical model, depending on radon flux from soil and predicting the radon progeny concentrations in hydrometeors forming at the ESHs is presented. The comparison between model and field data shows a good correspondence. Around nuclear power plants or in nuclear facilities that use automatic NaI or CsI total gamma spectroscopy systems for monitoring radioactive contamination, hydrometeors forming at the ESHs in sites with a high radon flux could represent a relevant source of false alarms of radioactive contamination. © The Author 2011. Published by Oxford University Press. All rights reserved. Source

Schildgen T.F.,University of Potsdam | Yildirim C.,Technical University of Istanbul | Cosentino D.,Third University of Rome | Cosentino D.,CNR Institute of Environmental Geology and Geoengineering | Strecker M.R.,University of Potsdam
Earth-Science Reviews | Year: 2014

The Central and Eastern Anatolian plateaus are integral parts of the world's third largest orogenic plateau. In the past decade, geophysical surveys have provided insights into the crust, lithosphere, and mantle beneath Eastern Anatolia. These observations are now accompanied by recent surveys in Central Anatolia and new data constraining the timing and magnitude of uplift along its northern and southern margins. Together with predictions from geodynamic models on the effects of various processes on surface deformation and uplift, the observations can be integrated to identify probable mechanisms of Anatolian Plateau growth.A changeover from shortening to extension along the southern margin of Central Anatolia that is coeval with the start of uplift can be most easily associated with oceanic slab break-off and tearing. This interpretation is supported by tomography, deep seismicity (or lack thereof), and gravity data. Based on the timing of uplift, geophysical and geochemical observations, and model predictions, slab break-off likely occurred first beneath Eastern Anatolia in middle to late Miocene time, and propagated westward toward Cyprus by the latest Miocene. Alternatively, the break-off near Cyprus could have occurred in late Pliocene to early Pleistocene time, in association with collision of the Eratosthenes Seamount (continental fragment) with the subduction zone. Uplift at the northern margin of Central Anatolia appears to result from crustal shortening starting in the late Miocene or early Pliocene, which has been linked to the broad restraining bend of the North Anatolian Fault. The uplift history of the interior of Central Anatolia since the late Miocene is unclear, although shortening there appears to have ended by the late Miocene, followed by NE-SW extension. This change in the deformation style broadly coincides with faster retreat of the Hellenic trench as well as uplift of the northern and southern margins of Central Anatolia.These different events throughout the plateau may be linked, as faster retreat of the Hellenic trench has been predicted to occur after slab break-off, which could have induced extension of Central Anatolia and helped to form the North Anatolian Fault through accelerated westward movement of Anatolia relative to Eurasia. Correlative geochronologic evidence that we summarize here supports the hypothesis that the geodynamic activity throughout the Aegean-Anatolian domain starting in latest Miocene to early Pliocene time defines a series of events that may all be linked to slab break-off. © 2013 Elsevier B.V. Source

Lobo F.J.,University of Granada | Ridente D.,CNR Institute of Environmental Geology and Geoengineering
Marine Geology | Year: 2014

This study is a review of Quaternary Milankovitch cycles as recorded on modern continental shelves worldwide. On the background of the many existing examples, we focus on selected case studies from Mediterranean (Adriatic and Tyrrhenian seas) and Atlantic (gulfs of Mexico and Cádiz) margins that represent general and peculiar characters of Middle-Upper Pleistocene sequences forming under the control of composite 100 and 20. ka Milankovitch cycles. The most pervasive stratigraphic pattern displayed by shelf deposits is referred to the 100. ka sea-level cycle, and consists of fairly uniform depositional sequences mostly composed by regressive deposits forming during the falling limb of the sea-level curve. These are generally classified as Falling Stage Systems Tract (FSST) and display a regressive facies architecture reflecting the dominant control of sea level. On many margins, FSST units may show slight though significant differences with respect to Highstand Systems Tract (HST) and Lowstand Systems Tract (LST) regressive units, more closely reflecting environmental changes and the local variability of depositional systems. In contrast with the theoretical and overall scale-independent model developed to predict composite stratigraphic cycles and sequences, the Middle-Upper Pleistocene stratigraphic record from numerous shelf settings shows a subdued signature of the higher-frequency (20. ka) Milankovitch cyclicity. However, when detectable, the 20. ka architectural pattern is characterized by a relatively greater spatial and temporal variability compared to 100. ka sequences. This fact likely reflects the increasing importance of factors controlling the depositional environment (e.g., seafloor morphology, oceanographic regime, sediment input and dispersal, etc) with respect to sea-level change during the shorter intervals encompassed by 20. ka. cycles. On this basis, two end-member cases have been distinguished, depending on the generation or not of high-frequency sequence boundaries, a prerequisite to qualify the higher-frequency motifs as depositional sequences. These two end members are comprehensive of the highly variable patterns displayed by Middle-Upper Pleistocene shelf sequences, which in turn reflect the interplay between the geological setting, the dominant sea-level control and the effective response of sedimentary systems. The variable stratigraphic patterns of Milankovitch cycles represent conceptual and practical constraints as to the classification of high-frequency Quaternary sequences under the general schemes of the standard sequence stratigraphy model. © 2013 Elsevier B.V. Source

Lustrino M.,University of Rome La Sapienza | Lustrino M.,CNR Institute of Environmental Geology and Geoengineering | Duggen S.,Leibniz Institute of Marine Science | Duggen S.,Minority | Rosenberg C.L.,Free University of Berlin
Earth-Science Reviews | Year: 2011

The central-western Mediterranean area is a key region for understanding the complex interaction between igneous activity and tectonics. In this review, the specific geochemical character of several 'subduction-related' Cenozoic igneous provinces are described with a view to identifying the processes responsible for the modifications of their sources. Different petrogenetic models are reviewed in the light of competing geological and geodynamic scenarios proposed in the literature.Plutonic rocks occur almost exclusively in the Eocene-Oligocene Periadriatic Province of the Alps while relatively minor plutonic bodies (mostly Miocene in age) crop out in N Morocco, S Spain and N Algeria. Igneous activity is otherwise confined to lava flows and dykes accompanied by relatively greater volumes of pyroclastic (often ignimbritic) products. Overall, the igneous activity spanned a wide temporal range, from middle Eocene (such as the Periadriatic Province) to the present (as in the Neapolitan of southern Italy). The magmatic products are mostly SiO2-oversaturated, showing calcalkaline to high-K calcalcaline affinity, except in some areas (as in peninsular Italy) where potassic to ultrapotassic compositions prevail. The ultrapotassic magmas (which include leucitites to leucite-phonolites) are dominantly SiO2-undersaturated, although rare, SiO2-saturated (i.e., leucite-free lamproites) appear over much of this region, examples being in the Betics (southeast Spain), the northwest Alps, northeast Corsica (France), Tuscany (northwest Italy), southeast Tyrrhenian Sea (Cornacya Seamount) and possibly in the Tell region (northeast Algeria).Excepted for the Alpine case, subduction-related igneous activity is strictly linked to the formation of the Mediterranean Sea. This Sea, at least in its central and western sectors, is made up of several young (<30Ma) V-shaped back-arc basins plus several dispersed continental fragments, originally in crustal continuity with the European plate (Sardinia, Corsica, Balearic Islands, Kabylies, Calabria, Peloritani Mountains). The bulk of igneous activity in the central-western Mediterranean is believed to have tapped mantle 'wedge' regions, metasomatized by pressure-related dehydration of the subducting slabs. The presence of subduction-related igneous rocks with a wide range of chemical composition has been related to the interplay of several factors among which the pre-metasomatic composition of the mantle wedges (i.e., fertile vs. refractory mineralogy), the composition of the subducting plate (i.e., the type and amount of sediment cover and the alteration state of the crust), the variable thermo-baric conditions of magma formation, coupled with variable molar concentrations of CO2 and H2O in the fluid phase released by the subducting plates are the most important.Compared to classic collisional settings (e.g., Himalayas), the central-western Mediterranean area shows a range of unusual geological and magmatological features. These include: a) the rapid formation of extensional basins in an overall compressional setting related to Africa-Europe convergence; b) centrifugal wave of both compressive and extensional tectonics starting from a 'pivotal' region around the Gulf of Lyon; c) the development of concomitant Cenozoic subduction zones with different subduction and tectonic transport directions; d) subduction 'inversion' events (e.g., currently along the Maghrebian coast and in northern Sicily, previously at the southern paleo-European margin); e) a repeated temporal pattern whereby subduction-related magmatic activity gives way to magmas of intraplate geochemical type; f) the late-stage appearance of magmas with collision-related 'exotic' (potassic to ultrapotassic) compositions, generally absent from simple subduction settings; g) the relative scarcity of typical calcalkaline magmas along the Italian peninsula; h) the absence of igneous activity where it might well be expected (e.g., above the hanging-wall of the Late Cretaceous-Eocene Adria-Europe subduction system in the Alps); i) voluminous production of subduction-related magmas coeval with extensional tectonic rìgimes (e.g., during Oligo-Miocene Sardinian Trough formation).To summarize, these salient central-western Mediterranean features, characterizing a late-stage of the classic 'Wilson Cycle' offer a 'template' for interpreting magmatic compositions in analogous settings elsewhere. © 2010 Elsevier B.V. Source

Discover hidden collaborations