ALBERT

Description: Foraminifera are unicellular eukaryotic organisms that live individually autonomous in the sea (Hottinger, 2005). They form mechanically resistant tests, either by gluing material found in the environment or by secreting organic or calcareous shells. Along with the test, main characteristic of foraminifera are their pseudopodia emerging from the cell body through multiple apertures. Foraminifera are extremely abundant in marine sediments, which makes them useful in recent and fossil paleoenvironmental studies. The first simple forms of foraminifera appeared in Cambrian and since provide a long and well recorded evolutionary record throughout Paleozoic, Mesozoic and Cenozoic (BouDagher‐ Fadel, 2008). Based on life strategy, foraminifera are divided in two groups: benthic and planktonic foraminifera. Planktonic foraminifera passively float through the waters of open oceans moved by currents. Benthic foraminifera live on the sea floor; on the surface, buried into the sediment, or attached to plants, rocks or sediment particles. Based on their size and internal morphological structure benthic foraminifera can be divided into two groups; smaller and larger benthic foraminifera. The main criteria for identifying LBF is the complex internal structure which evolved to efficiently host photosymbionts, the key elements in the ecology of LBF. The symbiotic algae utilize the waste product of the foraminifera, allowing them to efficiently recycle of nutrients and to facilitate calcification (Ross, 1974; Leutenegger, 1984). This life strategy, LBF as a greenhouse, limits their occurrences to photic zone since algal symbionts are dependent on light for photosynthesis (Leutenegger, 1984). Besides light levels, the distribution and abundance of LBF is determined by relatively well‐known parameters, including hydrodynamic energy, water temperature, salinity, food availability and substrate type (Hottinger, 1983; Hohenegger, 1994; Renema, 2006). Therefore, the assemblage composition of fossil LBF can provide important and valuable data for paleoenvironmental reconstructions (Hallock and Glenn, 1986; Renema and Troelstra, 2001). Present day Southeast Asia represents the region that supports the most diverse marine ecosystems on Earth. The origin of this biodiversity is still unresolved, but it is proposed to be present at least since the Early Miocene (Renema et al., 2008). Therefore, the data acquired from the fossil assemblages may contribute to our understanding of this biodiversity hotspot. In this thesis Miocene LBF were investigated in order to provide new insights regarding their biostratigraphy and depositional paleonvironments of Indonesia. The focus of the research includes mixed carbonate‐siliciclastic (MCS) systems of the Kutai Basin in East Kalimantan. However, to provide a comparative model with the blue‐water systems (Wilson, 2012), the study also included localities from Bulu Formation with carbonate platform deposits in Central Java. Until recently, MCS systems were considered to be environments inhospitable for carbonate producers compared to the blue‐water marine systems, and hence were often neglected in biodiversity studies (Friedman, 1988). However, recent studies reveal high biodiversity in these turbid water settings, including corals (Santodomingo et al., in press), LBF (Novak and Renema, in press), algae (Rosler et al., in press), and bryozoans (Di Martino and Taylor, 2014). The Kutai Basin was a host for the development of numerous MCS systems, with a peak of their deposition during the Miocene (Wilson and Rosen, 1998; Wilson, 2005). Herein MCS systems are defined as in situ mixing (Mount, 1984) with the carbonate fraction consisting of autochthonous or parautochthonous death assemblages of calcareous organisms accumulated on or within siliciclastic substrates. In these systems LBF are important contributors to carbonate production, and combined with their high tolerance of terrigenous input, individually they are the most suitable taxa for paleoenvironmental reconstruction and interpretation in MCS systems (Lokier et al., 2009; Novak et al., 2013). By investigating LBF assemblages of Miocene MCS systems of the Kutai Basin by updating their biostratigraphy, providing environmental reconstructions, and comparing them with contemporaneous carbonate platform deposits, this research helps in untangling the origins of the Indo‐Pacific biodiversity hotspot.

Description: The jumbo squid, Dosidicus gigas, can survive extended forays into the oxygen minimum zone (OMZ) of the Eastern Pacific Ocean. Previous studies have demonstrated reduced oxygen consumption and a limited anaerobic contribution to ATP production, suggesting the capacity for substantial metabolic suppression during hypoxic exposure. Here, we provide a more complete description of energy metabolism and explore the expression of proteins indicative of transcriptional and translational arrest that may contribute to metabolic suppression. We demonstrate a suppression of total ATP demand under hypoxic conditions (1% oxygen, PO2=0.8 kPa) in both juveniles (52%) and adults (35%) of the jumbo squid. Oxygen consumption rates are reduced to 20% under hypoxia relative to air-saturated controls. Concentrations of arginine phosphate (Arg-P) and ATP declined initially, reaching a new steady state (~30% of controls) after the first hour of hypoxic exposure. Octopine began accumulating after the first hour of hypoxic exposure, once Arg-P breakdown resulted in sufficient free arginine for substrate. Octopine reached levels near 30 mmol g−1 after 3.4 h of hypoxic exposure. Succinate did increase through hypoxia but contributed minimally to total ATP production. Glycogenolysis in mantle muscle presumably serves to maintain muscle functionality and balance energetics during hypoxia. We provide evidence that post-translational modifications on histone proteins and translation factors serve as a primary means of energy conservation and that select components of the stress response are altered in hypoxic squids. Reduced ATP consumption under hypoxia serves to maintain ATP levels, prolong fuel store use and minimize the accumulation of acidic intermediates of anaerobic ATP-generating pathways during prolonged diel forays into the OMZ. Metabolic suppression likely limits active, daytime foraging at depth in the core of the OMZ, but confers an energetic advantage over competitors that must remain in warm, oxygenated surface waters. Moreover, the capacity for metabolic suppression provides habitat flexibility as OMZs expand as a result of climate change.

Description: Professor Dr. Achim Brauer lehnt an der Spüle. Ein kleines Glas Wein gönnt er sich, schließlich ist es keine alltägliche Situation für den GFZWissenschaftler. Gleich wird er einen Vortrag halten. In einem Wohnzimmer.

Description: Since 2000 a joint project between the Department of Earth Science of Florence and the Unit of Environment and Health of the Municipality of Arezzo has allowed to geochemically characterise the superficial and ground waters of the municipal territory of Arezzo in order to establish the water quality and to investigate the main natural and anthropic processes responsible of their composition. The available geochemical data-base consists of more than 500 samples sites (90% of which are private wells and 7 and 3% are springs and running waters, respectively) on which physical parameters (temperature and electrical conductivity) and major, minor and trace dissolved species (pH, Ca, Mg, Na, K, NH4, HCO3, SO4, NO3, NO2, Cl, Br, F, heavy metals) have been performed by using the same sampling procedure and analytical methodology in order to have a consistent set of data. Fifteen selected sites have been analysed twice per year to evidence possible seasonal effects. No significant differences have been recorded. The Arezzo Basin, formed since Upper Pliocene, is a structural depression limited to the North and to the East by the Pratomagno and Chianti belts, respectively, and to the South and to the East by two tectonic lineaments (Val d’Arbia-Val Marecchia transversal and Chitignano normal faults). Along these tectonic discontinuities CO2-rich manifestations either seep out or exploited by private companies. Hydrogeologically, three main aquifers are recognised: i) a relatively deep aquifer hosted in Tertiary sandstone formations; ii) an intermediate aquifer hosted in Quaternary fluvio-lacustrine sediments and iii) a shallow aquifer in recent alluvional sediments. The content in Total Dissolved Solids (TDS) allows to classify the Arezzo waters in: oligomineral (69%), medium-mineral (30%) and mineral (1%) and they can be regarded as Ca(Mg)-HCO3 (87 %), Na(K)-HCO3 (7%), Ca(Mg)-SO4 (5%) and Na(K)-Cl (1%). It is noteworthy to point of that the Na(K)-HCO3 waters are aligned along the above mentioned tectonic systems. The quality of Arezzo waters has been referred to the Italian legislation that is addressed to the definition of the Maximum Admissible Concentration (MAC, DPR 236/88, Dlgs 31/01) and the Reference Value (RV, DPR 236/88) in terms of waters for the human consumption. Waters from the northern area of Arezzo overcome MAC for chlorides, sulphates and sodium; if we consider nitrogen species (NH4, NO2, NO3) the values overcome CMA for those waters collected into the city, its peripheral areas and in the south-western suburbs. Thematic maps has been produced, on the basis of the principles of linear Geostatistics, in order to analyse the spatial behaviour of the analysed variables. The aim was to find correlations with lithology, use of the soils, drainage density, pressure of antrophic activities and so on, and to identify sensible areas to monitor in their time evolution. The investigation has been developed starting from a detailed variographic analysis by means of the geochemical behaviour of each variable has been analysed in the different directions of the space while the estimation procedure to obtain the maps has been based on the application of sequential Gaussian simulation procedures.

Description: Published

Description: Spoleto, Italy

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: EnCana’s CO2 injection EOR project at Weyburn (Saskatchewan, Canada) is the focal point of a multi-faceted research program, sponsored by IEA GHG R&D and numerous international industrial and government partners including the European Community (BGS, BRGM, INGV and GEUS research providers), to find co-optimization of “CO2-EOR Production” and “CO2 -Geological Storage”, addressed to environmental purposes, in the frame of the Kyoto Agreement Policies. The Weyburn oil-pull is recovered from Midale Beds (at the depth of 1300-1500 m). This formation consists of Mississipian shallow marine carbonate-evaporites that can be subdivided into two units: i) the dolomitic “Marly” and ii) the underlying calcitic “Vuggy”, sealed by an anhydrite cap. Presently, around 3 billions mc of supercritical CO2 have been injected into the “Phase A1”injection area that includes around 90 oil producers, 30 water injectors and 30 CO2 injection wells, build up since September 2000. INGV has carried out a geochemical monitoring programme -approximately thrice yearly from pre-injection (“Baseline” trip, August 2000) to September 2004- performing trace element and dissolved gas analysis along with fluids sampling surveys, the latter being performed by the Canadian partners. The experimental data are the base of a geochemical modelling, i.e. the main goal of the present study. In the past, assumptions and gap-acceptance have been made in the literature in the frame of the geochemical modelling of CO2 geological storage, in order to reconstruct the reservoir conditions (pressure, pH and boundary conditions). As these parameters of deep fluids cannot be measured in-situ, all this information must be computed by a a posteriori procedure involving the analytical data. In this work we applied a geochemical model to: i) reconstruct the in-situ reservoir chemical composition (including pH) and ii) evaluate the boundary conditions (pCO2, pH2S), necessary to implement the reaction path modelling. This is the starting point to assess the geochemical impact of CO2 into the oil reservoir and, as main target, to quantify water-gas-rock reactions. Our geochemical modelling procedure is based on the available data such as: a) bulk mineralogy of the Marly and Vuggy zones; b) gas-cap composition and c) pre-and post-CO2 injection selected water samples from Midale Beds. The PRHEEQC (V2.11) Software Package was used to reconstruct the in-situ reservoir composition by calculating the chemical equilibrium among the various phases at reservoir temperature (60°C) and pressure (150 bars) conditions by suitable thermodynamic corrections to code database. Then, we identified possible compositions of the initially reservoir liquid phases, always taking into account the case histories of the Marly and Vuggy units. Finally, we modelled the geochemical impact of CO2 injection on Weyburn reservoir subjected to both local equilibrium and kinetically controlled reactions. The inverse modelling simulation (IMS) was then performed in order to calculate the amounts of mass transfer of liquid, gas and solid phases that accounted for changes in the water chemistry between the 2000 and 2003 data-sets. IMS calculations suggest that the reservoir underwent mineralogical changes, such as precipitation of chalcedony, gypsum and kaolinite and dissolution of anhydrite and k-feldspar. Calcite dissolution is predicted, but the precipitation of others carbonates (dolomite, dawsonite and siderite) can also occur. All experimental data and geochemical modelling confirm that “solubility trapping” is prevailing in this early stage of CO2 injection. Further and detailed studies are necessary until all the kinetic parameters will fully be identified. Thermo-kinetic modeling of the evolution of the CO2-rich Weyburn brine interacting with host rock minerals over 1000 years is one of main aims of this study in the framework of a PhD programme between the INGV of Rome and the Department of Earth Sciences of Florence.

Description: Published

Description: Spoleto, Italy

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: In this paper thematic maps produced on the basis of the principles of linear geostatistics are described in order to characterise the superficial and ground waters of the municipal territory of Arezzo. The aim is to assess the correlation with lithology, use of soil, drainage density and anthropogenic pressure and identify sensible areas to be periodically monitored in time. This study has used an original geochemical data-base consisting of about 500 water samples. A statistical approach has been used for the identification of anomalous values and homogenous populations. This step was followed by a detailed variographic study in order to analyse the spatial behaviour of the variables. Subsequently, an estimation procedure based on the application of ordinary kriging algorithm and sequential Gaussian simulation methods was applied to obtain the maps.

Description: Published

Description: San Giovanni valdarno (AR), Italy

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: EnCana’s CO2 injection EOR project at Weyburn (Saskatchewan, Canada) is the focal point of a multi-faceted research program, sponsored by IEA GHG R&D and numerous international industrial and government partners including the European Community (BGS, BRGM, INGV and GEUS research providers), to find co-optimization of “CO2-EOR Production” and “CO2 -Geological Storage”, addressed to environmental purposes, in the frame of the Kyoto Agreement Policies. The Weyburn oil-pull is recovered from Midale Beds (at the depth of 1300-1500 m). This formation consists of Mississipian shallow marine carbonate-evaporites that can be subdivided into two units: i) the dolomitic “Marly” and ii) the underlying calcitic “Vuggy”, sealed by an anhydrite cap. Presently, around 3 billions mc of supercritical CO2 have been injected into the “Phase A1”injection area that includes around 90 oil producers, 30 water injectors and 30 CO2 injection wells, build up since September 2000. INGV has carried out a geochemical monitoring programme -approximately thrice yearly from pre-injection (“Baseline” trip, August 2000) to September 2004- performing trace element and dissolved gas analysis along with fluids sampling surveys, the latter being performed by the Canadian partners. The experimental data are the base of a geochemical modelling, i.e. the main goal of the present study. In the past, assumptions and gap-acceptance have been made in the literature in the frame of the geochemical modelling of CO2 geological storage, in order to reconstruct the reservoir conditions (pressure, pH and boundary conditions). As these parameters of deep fluids cannot be measured in-situ, all this information must be computed by a a posteriori procedure involving the analytical data. In this work we proposed an approach to geochemical modeling in order to:: i) reconstruct the in-situ reservoir chemical composition (including pH) and ii) evaluate the boundary conditions (e.g. pCO2, pH2S), necessary to implement the reaction path modelling. This is the starting point to assess the geochemical impact of CO2 into the oil reservoir and, as main target, to quantify water-gas-rock reactions. Our geochemical modelling procedure is based on the available data such as: a) bulk mineralogy of the Marly and Vuggy zones; b) average gas-cap composition and c) pre-and post-CO2 injection selected water samples from Midale Beds. The PRHEEQC (V2.11) Software Package was used to reconstruct the in-situ reservoir composition by calculating the chemical equilibrium among the various phases at reservoir temperature (60°C) and pressure (150 bars) conditions by suitable thermodynamic corrections to code database. Then, we identified possible compositions of the initially reservoir liquid phases, always taking into account the case histories of the Marly and Vuggy units. The inverse modelling simulation (IMS) was then performed in order to calculate the amounts of mass transfer of liquid, gas and solid phases that accounted for changes in the water chemistry between the 2000 and 2003 data-sets. IMS calculations suggest that the reservoir underwent mineralogical changes, such as precipitation of chalcedony, gypsum and kaolinite and dissolution of anhydrite and k-feldspar. Calcite dissolution is predicted, but the precipitation of others carbonates (dolomite, dawsonite and siderite) can also occur. Finally, we modelled the geochemical impact of CO2 injection on Weyburn reservoir subjected to both local equilibrium and kinetically controlled reactions. All experimental data and thermo-kinetic modeling of the evolution of the CO2-rich Weyburn brine interacting with host rock minerals performed over 100 years after injection confirm that “solubility trapping” is prevailing in this early stage of CO2 injection. Further and detailed studies on the evolution of the CO2-rich Weyburn brine is one of main aims of this study in the framework of a PhD programme between the INGV of Rome and the Department of Earth Sciences of Florence.

Description: Published

Description: Berkeley, California (USA)

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: CO2 Capture & Storage (CCS) is presently one of the most promising technologies for reducing anthropogenic emissions of CO2. The numerical modeling procedures of geochemical processes are one of the few approaches for investigating the short-long-term consequences of CO2 storage into a deep reservoir. We present the results of a new approach for the reconstruction of thermo-physical properties of an off-shore deep well (situated in the medium Tyrrhenian Sea, only 5 miles from the coast, in the frame of a distensive and relatively high heat flux regime as a whole,with good outcrops, on-shore, of its stratigraphy includes six Late Triassic-Early Jurassic carbonatic formations at the depth of 2500-3700 m b.s.l). We used the well-log coupled with temperature profile and new mineralogical analyses of the outcrops geological formations, being the original core data lacking. This kind of procedure is new as a whole, and it is useful to create background petro-physical data, for reservoir engineering numerical simulations both of mass-transport and geochemical as well as geo-mechanical, in order to asses its general properties, without re-opening the well itself for industrial use, such as CO2 geological storage. The profile of thermal capacity and conductivity, as well as porosity and permeability resulted very well constrained and detailed for further numerical simulation uses. Porosity is a very important parameter for reservoir engineering, mainly for numerical simulations including geochemical modelling, being strongly necessary for CO2 geological storage feasibility studies, because it allows to compute: i) the reservoir storage capacity for each trapping mechanisms (some algorithms are discussed in the presentation) and ii) the water/rock ratio (one of the input parameter requested by the geochemical software codes). A common problem, working with closed wells with, available the well-log report only, is to obtain data on the thermo-physical properties of the rock. Usually the available well-log report the temperature profile measured during drilling, the mud-loss and some other information on water and gas phase presence. In this work we present a procedure that allow to estimate porosity and permeability of the rock formation from the well-log data joint with a rough mineralogical analyses of the corresponding geological formations outcrop with the use of a boundary condition such as shallow heat flow measurements; a similar approach were presented from some authors that dealt with similar problems e.g. Singh V.K., (2007). The analyses of the rock samples proceed by using i) petro-graphical analyses; ii) calcimetry with Dietrich-Fruhling apparatus in order to analyse the carbonate content of each sample; iii) XRD Rietveld analyses in order to quantify the major mineralogy of each sample and to apply the dolomite correction to the results of calcimetry determination. Rietveld quantification procedure were performed by using Maud v 2.2.; iv) SEM analyses have been accomplished later in details. Successively, hints about the subsequent geochemical modelling approach are presented. Chemical composition of the aquifer pore water has been has been inferred by batch modeling assuming thermodynamic equilibrium between minerals and a NaCl equivalent brine at reservoir conditions (up to 70 °C and 200 bar). Numerical simulations has been carried out by the PRHEEQC (V2.11) Software Package via corrections to the code default thermodynamic to obtain a more realistic modeling.

Description: Published

Description: La Habana, Cuba

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: In this study numerical simulations of reactive transport in an off-shore deep saline aquifer for the geological sequestration of carbon dioxide are presented and discussed. The main goals are to assess: i) the CO2 injection impact in the reservoir and ii) the cap-rock stability, both being strategic requisites for feasibility studies that are about to be started in Italy. The stratigraphic succession is characterized by a sedimentary succession: from Triassic anhydrites to Jurassic Tuscan calcareous units, up to Cretaceous calcarenites, belonging to the Liguride units, and Quaternary shallow marine sediments. Stratigraphic data from a deep well indicate that below an 1,800 m thick cap-rock, constituted by allochtonous marly calcarenites and clay marls, a regional deep saline aquifer is present. This aquifer, hosted in six Late Triassic to Early Jurassic formations, belonging to the Tuscan Nappe units, consists of porous limestone (mainly calcite) and marly limestone deposits at 1900-3100 m b.s.l. A common problem working with off-shore closed wells, where only the well-log information are available, is that to obtain reliable physico-chemical parameters (e.g. petrophysical and mineralogical) to be used for numerical simulations. Available site-specific data include only basic physical parameters such as temperature, pressure, and salinity of the formation waters. Bulk and modal mineralogical composition were obtained after sampling each formation in contiguous on-shore zones. Mineralogy was determined by X-Ray diffraction analysis coupled with Rietfield refinement. The latter was performed using Maud v2.2. The surface reactive area of minerals was assumed as geometric area of a truncated sphere calculated on the basis of Scanning Electronic Microscopy analysis. Porosity and permeability were inferred by the well-log data along with the use of boundary conditions such as surficial measurements and temperature profiles. The chemical composition of the aquifer pore water is unknown. As a consequence, this was calculated by batch modeling, assuming thermodynamic equilibrium between minerals and a NaCl (0.45 M) equivalent brine at reservoir conditions (up to 118 °C and 300 bars). The reconstructed dataset represented the base of numerical simulations to evaluate the potential geochemical impact of CO2 storage and to quantify water-gas-rock reactions. Three dimensional simulations were performed by the TOUGHREACT code via the implementation to the source code and the correction of the chemical parameters at the theoretical CO2 injection pressure. A re-interpretation of the available seismic reflection data was carried out to: i) define the 3D geometry, and ii) evaluate the volume of the geological structure potentially suitable for CO2 storage. In particular the main surfaces where physicochemical modeling was applied, i.e. the top and the bottom of the cap-rock units and the spill point surface, to better define the 3D geometry of the potential injection reservoir, were reconstructed. Reactive transport simulations were conducted under multiphase advection, aqueous diffusion, gas phase participation in multiphase fluid flow and geochemical reaction in non-isothermal conditions. Feedbacks between flow and geochemical processes were taken into account to evaluate changes in porosity and permeability as kinetic reactions were proceeding. Twenty years of CO2 injection at the rate of 1.5 Mt/year were simulated, whereas water-gas-rock interactions between CO2-rich brines and minerals over a period of 100 years were performed. Preliminary results suggest that injected CO2 can safely be retained in the reservoir by mineral trapping and that the cap-rock can be considered as efficient barrier.

Description: Published

Description: Rimini (Italy)

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: In this paper, we propose a new model of the crustal structure and seismotectonics for central Sicily (southern Italy) through the analysis of the depth distribution and kinematics of the instrumental seismicity, occurring during the period from 1983 to 2010, and its comparison with individual geological structures that may be active in the area. The analysed data set consists of 392 earthquakes with local magnitudes ranging from 1.0 to 4.7. We defined a new, detailed 1-D velocity model to relocate the earthquakes that occurred in central Sicily, and we calculated a Moho depth of 37 km and a mean VP/VS ratio of 1.73. The relocated seismic events are clustered mainly in the area north of Caltanissetta (e.g. Mainland Sicily) and in the northeastern sector (Madonie Mountains) of the study area; only minor and greatly dispersed seismicity is located in the western sector, near Belice, and along the southern coast, between Gela and Sciacca. The relocated hypocentral distribution depicts a bimodal pattern: 50 per cent of the events occur within the upper crust at depths less than ~16 km, 40 per cent of the events occur within the middle and depth crust, at depths between 16 and 32 km, and the remaining 10 per cent occur at subcrustal depths. The energy release pattern shows a similar depth distribution. On the basis of the kinematic analysis of 38 newly computed focal plane solutions, two major geographically distinct seismotectonic domains are distinguished: the Madonie Mountain domain, with prevalent extensional and extensional-oblique kinematics associated with upper crust Late Pliocene–Quaternary faulting, and the Mainland Sicily domain, with prevalent compressional and compressional-oblique kinematics associated with thrust faulting, at mid to deep crust depth, along the north-dipping Sicilian Basal Thrust (SBT). The stress inversion of the Mainland Sicily focal solutions integrated with neighbouring mechanisms available in the literature highlights a regional homogeneous compressional tensor, with a subhorizontal NNW–SSE-striking σ1 axis. In addition, on the basis of geodetic data, the Mainland Sicily domain may be attributed to the SSE-ward thrusting of the Mainland Sicily block along the SBT plane. Seismogenic shearing along the SBT at mid-crustal depths was responsible for the unexpected Belice 1968 earthquake (Mw 6.1), with evident implications in terms of hazard assessment.

Description: Published

Description: 1237-2252

Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale

Description: 3.2. Tettonica attiva

Description: 3.3. Geodinamica e struttura dell'interno della Terra

Description: 5.2. TTC - Banche dati di sismologia strumentale

Description: JCR Journal

Description: restricted

Description: New high-resolution bathymetric and magnetic data from the western Aeolian sector, southern Tyrrhenian Sea, provide insights into structural and volcanic development of the area, suggesting a strong interaction between volcanism and tectonics. The analysis of these data combined with relocated earthquake distribution, focal plane solutions and strain rate evaluation indicates that the dextral strike-slip Sisifo-Alicudi shear zone is a complex and wide area of active deformation, representing the superficial expression of the deep seated lithospheric tear fault separating the subduction slab below Sicily and Calabria. Most of the observed volcanic features are aligned along a NW–SE trend, such as the Filicudi island-Alicudi North Seamount and Eolo-Enarete alignments, and are dissected by hundred-metre-high scarps along conjugate NNE–SSW trending fault systems. The magnetic field pattern matches the main trends of volcanic features. Spectral analysis and Euler deconvolution of magnetic anomalies show the existence of both deep and shallow sources. High-amplitude, high-frequency anomalies due to shallow sources are dominant close to the volcanic edifices of Alicudi and Filicudi, while the main contribution on the surrounding Eolo, Enarete, Alicudi North and Filicudi North seamounts is given by low-amplitude anomalies and/or deeper magnetic sources. This is probably related to different ages of the volcanic rocks, although hydrothermal processes may have played an important role in blanketing magnetic anomalies, in particular at Enarete and Eolo seamounts. Relative chronology of the eruptive centres and the inferred deformation pattern outline the Quaternary evolution of the western Aeolian Arc: Sisifo, Alicudi North and Filicudi North seamounts might have developed in an early stage, following the Late Pliocene–Early Pleistocene SE-ward migration of arc-related volcanism due to the Ionian subduction hinge retreat; Eolo, Enarete and Filicudi represent later manifestations that led volcanoes to develop duringMid-Late Pleistocene, when the stress regime in the area changed, due to the SSE-ward propagation of the subduction slab tear fault and the consequent reorientation and decrease of trench migration velocity. Finally, volcanic activity occurred in a very short time span at Alicudi, where an almost conical volcanic edifice emerged, suggesting negligible interactions with regional fault systems.

Description: Published

Description: 64-78

Description: 2.6. TTC - Laboratorio di gravimetria, magnetismo ed elettromagnetismo in aree attive

Description: 3.3. Geodinamica e struttura dell'interno della Terra

Description: 3.4. Geomagnetismo

Description: JCR Journal

Description: restricted

Description: A systematic analysis is made of static Coulomb stress changes and earthquake occurrence in the area of the North Aegean Sea, Greece, in order to assess the prospect of using static stress changes to construct a regional earthquake likelihood model.

Description: A systematic analysis is made of static Coulomb stress changes and earthquake occurrence in the area of the North Aegean Sea, Greece, in order to assess the prospect of using static stress changes to construct a regional earthquake likelihood model. The earthquake data set comprises all events of magnitude M ≥ 5.2 which have occurred since 1964. This is compared to the evolving stress field due to constant tectonic loading and perturbations due to coseismic slip associated with major earthquakes (M ≥ 6.4) over the same period. The stress was resolved for sixteen fault orientation classes, covering the observed focal mechanisms of all earthquakes in the region. Analysis using error diagrams shows that earthquake occurrence is better correlated with the constant tectonic loading component of the stress field than with the total stress field changes since 1964, and that little, if any, information on earthquake occurrence is lost if only the maximum of the tectonic loading over the fault orientation classes is considered. Moreover, the information on earthquake occurrence is actually increased by taking the maximum of the evolving stress field since 1964, and of its coseismic–slip component, over the fault orientation classes. The maximum, over fault orientation classes, of linear combinations of the tectonic loading and the evolving stress field is insignificantly better correlated with earthquake occurrence than the maximum of the tectonic loading by itself. A composite stress–change variable is constructed from ordering of the maximum tectonic loading component and the maximum coseismic–slip component, in order to optimize the correlation with earthquake occurrence. The results indicate that it would be difficult to construct a time–varying earthquake likelihood model from the evolving stress field that is more informative than a time–invariant model based on the constant tectonic loading.

Description: This research was supported by the Foundation for Research, Science and Technology under contract CO5X0402. Geophysics Department, AUTH, contribution number 741.

Description: Published

Description: 1049–1066

Description: 6T. Studi di pericolosità sismica e da maremoto

Description: JCR Journal

Description: open

Description: A geochemical survey of 197 fluid discharges (cold and thermal waters and bubbling pools) and 15 gas emissions from the western sector of the Sabatini Volcanic District and the Tolfa Mountains (Latium, Central Italy) was carried out in 2007–2008. The chemical and isotopic compositions of the fluid discharges indicate the occurrence of two main sources: 1) relatively shallow aquifers with Ca(Na,K)–HCO3 and Ca(Mg)–HCO3 compositions when trapped in volcanic and sedimentary formations, respectively; and 2) a deep reservoir, which is hosted in the Mesozoic carbonate sequence, rich in CO2 and having a Ca–SO4(HCO3) composition. Dissolution of a CO2-rich gas phase into the shallow aquifers produces high-TDS and high-pCO2 cold waters, while oxidation of deep-derived H2S to SO4 2− generates low-pH (b4) sulfate waters. The δ13C–CO2 values for gas emissions (from−2.8 to+2.7‰vs. VPDB) suggest that the origin of CO2 associated with the deep fluids ismainly related to thermo-metamorphic reactions within the carbonate reservoir, although significant mantle contribution may also occur. However, R/Ra values (0.37–0.62) indicate that He is mainly produced by a crustal source, with a minor component from a crust-contaminated mantle. On the basis of the δ13C–CH4 and δD–CH4 values (from −25.7 to −19.5‰ vs. VPDB and from −152 to −93.4‰ vs. VSMOW, respectively) CH4 production is associated with thermogenic processes, possibly related to abiogenic CO2 reduction within the carbonate reservoir. The δ34S–H2S values (from+9.3 to +10.4‰ vs. VCDT) are consistent with the hypothesis of a sedimentary source of sulfur from thermogenic reduction of Triassic sulfates. Geothermometric evaluations based on chemical equilibria CO2–CH4 and, separately, H2S suggest that the reservoir equilibriumtemperature is up to ~300 °C. The δDand δ18O data indicate thatwater recharging both the shallow and deep aquifers has a meteoric origin. Fluid geochemistry, coupled with gravimetric data and tectonic lineaments, supports the idea that significant contributions from a deep-seated geothermal brine are present in the Stigliano thermal fluid discharges. Exploration surveys investigated this area during 70's–90's for geothermal purposes. Nevertheless, presently the area is still under-exploited. The presence of thermal waters and anomalous heat flow together with the demographic growth of the last years,makes this site a suitable location for direct applications of the geothermal resource.

Description: Published

Description: 160-181

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: JCR Journal

Description: reserved

Description: CO2 Capture & Storage (CCS) in saline aquifer is one of the most promising technologies for reducing anthropogenic emission of CO2. Feasibility studies for CO2 geo-sequestration in Italy have increased in the last few years. Before planning a CCS plant an appropriate precision and accuracy in the prediction of the reservoir evolution during injection, in terms of both geochemical calculation and fluid flow properties, is demanded. In this work a geochemical model will be presented for an offshore well in the Tyrrhenian Sea where the injection of 1.5 million ton/year of CO2 is planned. The dimension of the trapping structure requires to study an area of about 100 km2 and 4 km deep. Consequently, three different simulations were performed by means of TOUGHREACT code with Equation Of State module ECO2N. The first simulation is a stratigraphic column with a size of 110*110*4,000 meters and a metric resolution in the injection/cap-rock area (total of 8,470 elements), performed in order to asses the geochemical evolution of the cap-rock and to ensure the sealing of the system. The second simulation is at large scale in order to assess the CO2 path from the injection towards the spill point (total of about 154,000 elements). During this simulation, the effect of the full coupling of chemistry with fluid flow and a relevant effect in the expected CO2 diffusion velocity was recognized. Owing to the effect of chemical reaction and coupling terms (porosity/permeability variation with mineral dissolution/precipitation), the diffusion velocity results to be 20% slower than in a pure fluid flow simulation. In order to give a better picture of this 'barrier' effect, where the diffusion of the CO2-rich acidic water into the carbonate reservoir originates a complex precipitation/dissolution area, a small volume simulation with a 0.1 m grid was elapsed. This effect may potentially i) have a big impact on CO2 sequestration due to the reduction of available storage volume reached by the CO2 plume in 20 years and/or the enhanced injection pressure and ii) outline the relevance of a full geochemical simulation in an accurate prediction of the reservoir properties.

Description: Published

Description: Lawrence Berkeley National Laboratory, Berkeley, California

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: We presents the results of a new approach for the reconstruction of thermo-physical properties of deep well from the well log and mineralogical analisys of the outcrops formation. This kind of procedure are generally new, and they are useful for creating the background data for reservoir engeneers and geochemist for modelling a well in order to asses its properties prior of re-opening the well itself for industrial use, such as CO2 sequestration. We used the temperature profile obtained from the well log and the bulk mineralogy analysed from the corresponding formation outcrops. The profile of thermal capacity and conductivity, and porosity and permeability as well, result well constrained and detaile for further use.

Description: Published

Description: Firenze, Italy

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: CO2 Capture & Storage in saline aquifers is presently one of the most promising technologies for reducing anthropogenic emissions of CO2. In these sites the short-longterm consequences of CO2 storage into a deep reservoir can be predicted by numerical modelling of geochemical processes. Unfortunately a common problem working with off-shore closed wells, where only the well-log information are available, is to obtain physico-chemical data (e.g. petrophysical and mineralogical) needed to reliable numerical simulations. Available site-specific data generally include only basic physical parameters such as temperature, pressure, and salinity of the formation waters. In this study we present a methodological procedure that allows to estimate and integrate lacking information to geochemical modelling of deep reservoirs such as: i) bulk and modal mineralogical composition, ii) porosity and permeability of the rock obtained from heat flow measurements and temperature, iii) chemical composition of formation waters (at reservoir conditions) prior of CO2 injection starting from sampling of analogue outcropping rock formations. The data sets in this way reconstructed constitute the base of geochemical simulations applied on some deep-seated Italian carbonatic and sandy saline aquifers potentially suitable for geological CO2 storage. Numerical simulations of reactive transport has been performed by using the reactive transport code TOUGHREACT via pressure corrections to the default thermodynamic database to obtain a more realistic modelling. Preliminary results of geochemical trapping (solubility and mineral trapping) potentiality and cap-rock stability as strategic need for some feasibility studies near to be started in Italy are here presented and discussed.

Description: Submitted

Description: Davos, Svizzera

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: Gli elementi chimici disciolti nelle acque continentali provengono dall’alterazione della crosta terrestre. L’acqua erode e dissolve i minerali delle rocce attraverso l’alterazione chimica avvalendosi del contributo dei gas presenti in atmosfera o nel sottosuolo. Il nitrato, una delle sostanze responsabili delle più gravi forme di inquinamento delle acque nei paesi in via di sviluppo, è un nutriente essenziale per la crescita delle piante e rappresenta un anello fondamentale del ciclo biogeochimico dell'azoto, in quanto viene prodotto dai batteri a partire dall'azoto atmosferico. In quantità eccessive il nitrato può essere dannoso per gli uomini e per gli animali. Elevati livelli di nitrato nell'acqua sono causati in larga misura dall'uso di fertilizzanti ricchi di nitrato e dal letame. In questo contesto, le condizioni redox delle acque naturali, che controllano la speciazione dei composti dell’azoto, sono altamente variabili perché controllate prevalentemente dall’attività biologica. In particolare, il bilancio fra i due processi dell’attività biologica, la fotosintesi e la respirazione (o decomposizione della sostanza organica), determina la presenza nel sistema di condizioni ossidanti o riducenti. I composti dell’azoto possono quindi essere considerati utili indicatori dello stato di salute di un acquifero superficiale. In questo lavoro sono analizzati i dati relativi ai tenori delle specie dell’azoto NH4 +, NO2 - e NO3 - relativi ad acque di falda campionate nell’area aretina nel corso della realizzazione dell’Atlante Geochimico delle Acque di Falda e di Scorrimento Superficiale del Comune di Arezzo. I dati sono analizzati proponendo nuove metodologie grafiche e numeriche per visualizzare lo stato del territorio nei confronti della pressione antropica come rilevata dal comportamento spaziale e temporale delle specie suddette.

Description: Published

Description: Accademia Nazionale dei Lincei, Roma

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: open

Description: Geological storage is presently one of the most promising options for reducing anthropogenic emissions of CO2. Among the several projects investigating the fate of CO2 stored at depth, the EnCana's CO2 injection EOR (Enhancing Oil Recovery) project at Weyburn (Saskatchewan, Canada) is the most important oil production development that hosts an international monitoring project. In the Weyburn EOR Project CO2 is used to increase recovery of heavy oil from the Midale Beds, a Mississippian reservoir consisting of shallow marine carbonate, where about 3 billions standard m3 of supercritical CO2 have been injected since 2000 with an injection rate of 5000 ton/day. In this work the available dataset (bulk mineralogy of the reservoir, gas-cap composition and selected preand post-CO2 injection water samples) provided by the International Energy Agency Weyburn CO2 Monitoring & Storage Project has been used in order to: i) reconstruct the pre-injection reservoir chemical composition (including pH and the boundary conditions at 62 °C and 15 MPa); ii) assess the evolution of the reservoir subjected to CO2 injection and predict dissolution/precipitation processes of the Weyburn brines over 100 years after injection; iii) validate the short-term (September 2000–2003) evolution of the in situ reservoir fluids due to the CO2 injection, by comparing the surface analytical data with the composition of the computed depressurized brines. To achieve these goals the PRHEEQC (V2.14) Software Package was used with both modified thermodynamic database and correction for supercritical CO2 fugacity. The oil–gas–water interaction and the non-ideality of the gas phase (with exception of CO2) were not considered in the numerical simulations. Despite intrinsic limitations and uncertainties of geochemical modeling, the main results can be summarized, as follows: 1) the calculated pre-injection chemical composition of the Midale Beds brine is consistent with the analytical data of the waters collected in 2000 (baseline survey), 2) the main reservoir reactions (CO2 and carbonate dissolution) take place within the first year of simulation, 3) the temporal evolution of the chemical features of the fluids in the Weyburn reservoir suggests that CO2 can safely be stored by solubility (as CO2(aq)) and mineral trapping (via dawsonite precipitation). The short-term validation performed by calculating chemical composition of the reservoir fluids (corrected for surface conditions) after the simulation of 3 years of CO2 injection is consistent (error ≤5%) with the analytical data of the wellhead water samples collected in 2003, with the exception of Ca and Mg (error N90%), likely due to complexation effect of carboxilic acid.

Description: Published

Description: 181-197

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: JCR Journal

Description: partially_open

Description: A geochemical survey of the main thermal waters discharging in the southwestern part of the Domuyo volcanic complex (Argentina),where the latest volcanic activity dates to 0.11 Ma, has highlighted the extraordinarily high heat loss from this remote site in Patagonia. The thermal water discharges are mostly Na-Cl in composition and have TDS values up to 3.78 g L−1 (El Humazo). A simple hydrogeochemical approach shows that 1,100 to 1,300 kg s−1 of boiling waters, which have been affected by shallow steam separation, flow into the main drainage of the area (Rio Varvarco). A dramatic increase of the most conservative species such as Na, Cl and Li from the Rio Varvarco fromupstreamto downstreamwas observed and related solely to the contribution of hydrothermal fluids. The equilibrium temperatures of the discharging thermal fluids, calculated on the basis of the Na-K-Mg geothermometer, are between 190 °C and 230 °C. If we refer to a liquid originally at 220 °C (enthalpy = 944 J g−1), the thermal energy release can be estimated as high as 1.1±0.2 GW, a value that ismuch higher than the natural release of heat in other important geothermal fields worldwide, e.g., Mutnovsky (Russia), Wairakei (New Zealand) and Lassen Peak (USA). This value is the second highest measured advective heat flux from any hydrothermal system on Earth after Yellowstone.

Description: Published

Description: 71–77

Description: 4V. Vulcani e ambiente

Description: JCR Journal

Description: restricted

Description: Abstract A geochemical survey of fumarolic and submerged gases from fluid discharges located in the Nea Kameni and Palea Kameni islets (Santorini Island, Greece) was carried out before, during, and after the unrest related to the anomalously high seismic and ground deformation activity that affected this volcanic system since January 2011. Our data show that from May 2011 to February 2012, the Nea Kameni fumaroles showed a significant increase of H2 concentrations. After this period, an abrupt decrease in the H2 contents, accompanied by decreasing seismic events, was recorded. A similar temporal pattern was shown by the F−, Cl−, SO4 2−, and NH4 + concentrations in the fumarolic condensates. During the sharp increase of H2 concentrations, when values up to 158 mmol/ mol were measured, the δ13C–CO2 values, which prior to January 2011 were consistent with a dominant CO2 thermometamorphic source, have shown a significant decrease, suggesting an increase of mantle CO2 contribution. Light hydrocarbons, including CH4, which are controlled by chemical reactions kinetically slower than H2 production from H2O dissociation, displayed a sharp increase in March 2012, under enhanced reducing conditions caused by the high H2 concentrations of May 2011–February 2012. The general increase in light hydrocarbons continued up to July 2012, notwithstanding the contemporaneous H2 decrease. The temporal patterns of CO2 concentrations and N2/Ar ratios increased similarly to that of H2, possibly due to sealing processes in the fumarolic conduits that diminished the contamination related to the entrance of atmospheric gases in the fumarolic conduits. The compositional evolution of the Nea Kameni fumaroles can be explained by a convective heat pulse from depth associated with the seismic activation of the NE–SW-oriented Kameni tectonic lineament, possibly triggered by either injection of new magma below Nea Kameni island, as apparently suggested by the evolution of the seismic and ground deformation activity, or increased permeability of the volcanic plumbing system resulting from the tectonic movements affecting the area. The results of the present study demonstrate that the geophysical and geochemical signals at Santorini are interrelated and may be precursory signals of renewed volcanic activity and encourage the development of interdisciplinary monitoring program to mitigate the volcanic risk in the most tourist-visited island of the Mediterranean Sea.

Description: Published

Description: 711

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi

Description: JCR Journal

Description: restricted

Description: After the 1999 Ìzmit earthquake (Mw7.4), along the North-Anatolian Fault (NAF), an increase in gas emissions from the seafloor of the Sea of Marmara was observed. Using a multidisciplinary approach, that includes a combined analysis of high-resolution marine geophysical and gas-geochemical data, we determined the character of gas/fluid emissions and their spatial relationship with tectonic structures in the Darıca Basin (Gulf of Ìzmit), close to the western termination of the 1999 earthquake surface rupture. Data collected during several oceanographic expeditions allowed us to investigate the fine structure of active fault branches, as well as the geochemical signature of the cold seeps. We observed that gas emissions at the seafloor of the Darıca Basin are mostly constituted by biogenic CH4, and are aligned along strike-slip and transtensional fault segments. Although maximum CH4 concentrations were measured in correspondence of transtensional strands, we suggest that the biogenic CH4 emissions found along strike-slip segments, showing a relatively low gas background noise and a potential to increase during seismic events, are more suitable to study relationships between gas expulsion and the earthquake cycle.

Description: Published

Description: 371-384

Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi

Description: JCR Journal

Description: restricted

Description: This paper describes the chemical and isotope features of water and dissolved gases from lake Paterno (max. depth 54 m), a sinkhole located in the NE sector of the S. Vittorino plain (Rieti, Central Italy), where evidences of past and present hydrothermal activity exists. In winter (February 2011) lake Paterno waters were almost completely mixed, whereas in summer time (July 2011) thermal and chemical stratifications established. During the stratification period, water and dissolved gas chemistry along the vertical water column were mainly controlled by biological processes, such as methanogenesis, sulfate-reduction, calcite precipitation, denitrification, and NH4 and H2 production. Reducing conditions at the interface between the bottom sediments and the anoxic waters are responsible for the relatively high concentrations of dissolved iron (Fe) and manganese (Mn), likely present in their reduced oxidation state. Minerogenic and biogenic products were recognized at the lake bottom even during the winter sampling. At relatively shallow depth the distribution of CH4 and CO2 was controlled by methanotrophic bacteria and photosynthesis, respectively. The carbon isotope signature of CO2 indicates a significant contribution of deep-originated inorganic CO2 that is related to the hydrothermal system feeding the CO2-rich mineralized springs discharging in the surrounding areas of lake Paterno. The seasonal lake stratification likely controls the vertical and horizontal distribution of fish populations in the different periods of the year.

Description: Published

Description: 245-260

Description: 4.4. Scenari e mitigazione del rischio ambientale

Description: JCR Journal

Description: open

Description: Twelve anomalous layers, marked by a high concentration of displaced epiphytic foraminifera (species growing in vegetated substrates like the Posidonia oceanica) and subtle grain-size changes were found in a 6.7 mlong, fine sediment core (MS-06), sampled 2 kmoff the shore of the Augusta Harbor (Eastern Sicily) at a depth of 72 m, recording the past 4500 yrs of deposition. Because concentrations of epiphytic foraminifera are quite common in infralittoral zones, but not expected at −72 m, we believe that these anomalous layers might be related to the occurrence of tsunamis causing substantial uprooting and seaward displacement of P. oceanica blades with their benthic biota. Our approach involved the study of geophysical data (morphobathymetry, seismic reflection, and seafloor reflectivity) and sediment samples, including X-ray imaging, physical properties, isotopic dating, tephrochronology, grain-size and micropaleontology. Correlations between anomalous layers and tsunami events have been supported by a multivariate analysis on benthic foraminifera assemblage and dates of historical tsunami records. We found that four out of the eleven layers were embedded in age intervals encompassing the dates of major tsunamis that hit eastern Sicily (1908, 1693, and 1169) and the broader Eastern Mediterranean (Santorini at about BP 3600). One more layer, even if less distinct than the others, was also defined and may be the evidence for the AD 365 Crete tsunami.

Description: Published

Description: 1-13

Description: 3.2. Tettonica attiva

Description: JCR Journal

Description: partially_open

Description: Copahue volcano is part of the Caviahue–Copahue Volcanic Complex (CCVC),which is located in the southwestern sector of the Caviahue volcano-tectonic depression (Argentina–Chile). This depression is a pull-apart basin accommodating stresses between the southern Liquiñe–Ofqui strike slip and the northern Copahue–Antiñir compressive fault systems, in a back-arc setting with respect to the Southern Andean Volcanic Zone. In this study, we present chemical (inorganic and organic) and isotope compositions (δ13C-CO2, δ15N, 3He/4He, 40Ar/36Ar, δ13C-CH4, δD-CH4, and δD-H2O and δ18O-H2O) of fumaroles and bubbling gases of thermal springs located at the foot of Copahue volcano sampled in 2006, 2007 and 2012. Helium isotope ratios, the highest observed for a Southern American volcano (R/Ra up to 7.94), indicate a non-classic arc-like setting, but rather an extensional regime subdued to asthenospheric thinning. δ13C-CO2 values (from −8.8‰ to −6.8‰ vs. V-PDB), δ15N values (+5.3‰ to +5.5‰ vs. Air) and CO2/3He ratios (from 1.4 to 8.8 × 109) suggest that the magmatic source is significantly affected by contamination of subducted sediments. Gases discharged from the northern sector of the CCVC show contribution of 3He-poor fluids likely permeating through local fault systems. Despite the clear mantle isotope signature in the CCVC gases, the acidic gas species have suffered scrubbing processes by a hydrothermal system mainly recharged by meteoric water. Gas geothermometry in the H2O-CO2-CH4-CO-H2 system suggests that CO and H2 re-equilibrate in a separated vapor phase at 200°–220 °C. On the contrary, rock–fluid interactions controlling CO2, CH4 production from Sabatier reaction and C3H8 dehydrogenation seem to occur within the hydrothermal reservoir at temperatures ranging from 250° to 300 °C. Fumarole gases sampled in 2006–2007 show relatively low N2/He and N2/Ar ratios and high R/Ra values with respect to those measured in 2012. Such compositional and isotope variations were likely related to injection of mafic magma that likely triggered the 2000 eruption. Therefore, changes affecting the magmatic systemhad a delayed effect on the chemistry of the CCVC gases due to the presence of the hydrothermal reservoir. However, geochemical monitoring activities mainly focused on the behavior of inert gas compounds (N2 and He), should be increased to investigate the mechanism at the origin of the unrest started in 2011.

Description: Published

Description: 44–56

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi

Description: JCR Journal

Description: restricted

Description: The genetic relationship between carbon-bearing species (CO, CO2, CH4, C2H6, C3H8, C2H4 and C3H6) was investigated in volcanic-hydrothermal gases emitted from Nisyros (Greece), Vesuvio, La Solfatara (Campi Flegrei) and Pantelleria (all Italy). Apparent carbon isotopic temperatures of the CH4-CO2 system are ~360°C at Nisyros, 420-460°C at Vesuvio, ~450°C at La Solfatara and ~540°C at Pantelleria. These temperatures are confirmed by measured propene/propane and H2/H2O concentration ratios. CH4 and CO2 equilibrate in the single liquid phase prior to the onset of boiling, whereas propene and propane attain equilibrium in the saturated water vapor phase. Boiling in these high-enthalpy hydrothermal systems might occur isothermally. Once vapor has been extracted from the parental liquid, CO/CO2 responds most sensitively to the temperature gradient encountered by the ascending gases. Our results imply that the CH4-CO2 isotopic geothermometer can provide reliable information about temperatures of deep hydrothermal liquids associated with volcanism. Propene/propane and H2/H2O concentration ratios should be measured along with the carbon isotopic composition of CO2 and CH4 to provide independent constraints on the geological significance of the apparent carbon isotopic temperatures.

Description: Published

Description: 66–75

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: JCR Journal

Description: restricted

Description: In this paper, fluid source(s) and processes controlling the chemical composition of VOCs (Volatile Organic Compounds) in gas discharges from Mt. Etna and Vulcano Island (Sicily, Italy) were investigated. The main composition of the Etnean and Volcano gas emissions is produced by mixing, to various degrees, of “magmatic” and “hydrothermal” components. VOCs are dominated by alkanes, alkenes and aromatics, with minor, though significant, concentrations of O-, S- and Cl(F)-substituted compounds. The main mechanism for the production of alkanes is likely related to pyrolysis of organic matter-bearing sediments that interact with the ascending magmatic fluids. Alkanes are then converted to alkene and aromatic compounds via catalytic reactions (dehydrogenation and dehydroaromatization, respectively). Nevertheless, an abiogenic origin for the light hydrocarbons cannot be ruled out. Oxidative processes of hydrocarbons at relatively high temperatures and oxidizing conditions, typical of these volcanic-hydrothermal fluids, may explain the production of alcohols, esters, aldehydes, as well as O- and S-bearing heterocycles. By comparing the concentrations of hydrochlorofluorocarbons (HCFCs) in the fumarolic discharges with respect to those of background air, it is possible to highlight that they have a geogenic origin likely due to halogenation of both methane and alkenes. Finally, CFC (chlorofluorocarbon) abundances appear to be consistent with background air, although the strong air contamination that affects the Mt. Etna fumaroles may mask a possible geogenic contribution for these compounds. On the other hand, no CFCs were detected in the Vulcano gases, which are characterized by low air contribution. Nevertheless, a geogenic source for these compounds cannot be excluded on the basis of the present data.

Description: Published

Description: D17305

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: JCR Journal

Description: open

Description: Measurements of soil fluxes of hydrothermal gases, with special emphasis on C6H6, as well as chemical composition of mono-aromatic compounds in fumaroles and air, were carried out in April 2012 at the Solfatara crater (Campi Flegrei, Southern Italy) to investigate the distribution and behavior of these species as they migrate through the soil from their deep source to the atmosphere. Soil fluxes of CO2, CH4 and C6H6 exhibit good spatial correlation, suggesting that diffuse degassing is mainly controlled by local fractures. The calculated total output of diffuse C6H6 from Solfatara is 0.10 kg day 1, whereas fluxes of CO2 and CH4 are 79 103 and 1.04 kg day 1, respectively. A comparison between soil gas fluxes and fumarole composition reveals that within the crater soil CH4 is significantly affected by oxidation processes, which are more efficient for low gas fluxes, being dependent on the residence time of the uprising hydrothermal gases at shallow depth. Benzene degradation, mainly proceeding through oxidation via benzoate, seems to be strongly controlled by the presence of a shallow SO2 4 -rich aquifer located in the central and southwestern sectors of the crater, suggesting that the process is particularly efficient when SO2 4 acts as terminal electron acceptor (SO4 reduction). Relatively high C6H6/C7H8 ratios, typical of hydrothermal fluids, were measured in air close to the main fumarolic field of Solfatara crater. Here, C6H6 concentrations, whose detection limit is 0.1 lgm 3, are more than one order of magnitude higher than the limit value for ambient air (5 lgm 3). This suggests that hydrothermal fluids have a strong impact on air quality in the immediate surroundings of the fumarolic vents. Significant concentrations of endogenous mono-aromatics were also detected in air samples collected from the northern and western sides of the crater, where these gas compounds are mostly fed by diffuse degassing through the crater bottom soil.

Description: Published

Description: 142–153

Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi

Description: JCR Journal

Description: restricted

Description: We carried out a combined geophysical and gas-geochemical survey on an active fault strand along the North-Anatolian Fault (NAF) system in the Gulf of İzmit (eastern Sea of Marmara), providing for the first time in this area data on the distribution of methane (CH4) and other gases dissolved in the bottom seawater, as well as the CH4 isotopic composition. Based on high-resolution morphobathymetric data and chirp-sonar seismic reflection profiles we selected three areas with different tectonic features associated to the NAF system, where we performed visual and instrumental seafloor inspections, including in-situ measurements of dissolved CH4, and sampling of the bottom water. Starting from background values of 2-10 nM, methane concentration in the bottom seawater increases abruptly up to 20 nM over the main NAF trace. CH4 concentration peaks up to ~120 nM were detected above mounds related probably to gas and fluids expulsion. Methane is microbial (δ13CCH4: -67.3 and -76 ‰ vs. VPDB), and was found mainly associated with pre- Holocene deposits topped by a 10-20 m thick draping of marine mud. The correlation between tectonic structures and gas-seepages at the seafloor suggests that the NAF in the Gulf of İzmit could represent a key site for long-term combined monitoring of fluid exhalations and seismicity to assess their potential as earthquake precursors.

Description: Published

Description: Q10018

Description: 1.8. Osservazioni di geofisica ambientale

Description: JCR Journal

Description: restricted

Description: Lake Albano (Alban Hills volcanic complex, Central Italy) is located in a densely populated area near Rome. The deep lake waters have significant dissolved CO2 concentrations, probably related to sub-lacustrine fluid discharges fed by a pressurized CO2-rich reservoir. The analytical results of geochemical surveys carried out in 1989 2010 highlight the episodes of CO2 removal from the lake. The total mass of dissolved CO2 decreased from ∼5.8× 107 kg in 1989 to ∼0.5×107 kg in 2010, following an exponential decreasing trend. Calculated values of both dissolved inorganic carbon and CO2 concentrations along the vertical profile of the lake indicate that this decrease is caused by CO2 release from the epilimnion, at depth 〈9 m, combined with (1) water circulation at depth 〈95 m and (2) CO2 diffusion from the deeper lake layers. According to this model, Lake Albano was affected by a large CO2 input that coincided with the last important seismic swarm at Alban Hills in 1989, suggesting an intimate relationship between the addition of deep-originated CO2 to the lake and seismic activity. In the case of a CO2 degassing event of an order of magnitude larger than the one that occurred in 1989, the deepest part of Lake Albano would become CO2-saturated, resulting in conditions compatible with the occurrence of a gas outburst. These results reinforce the idea that a sudden CO2 input into the lake may cause the release of a dense gas cloud, presently representing the major volcanic threat for this densely populated area

Description: Published

Description: 861-871

Description: 2.4. TTC - Laboratori di geochimica dei fluidi

Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi

Description: JCR Journal

Description: reserved

Description: Episodic gas seepage occurs at the seafloor in the Gulf of Izmit (Sea of Marmara, NW Turkey) along the submerged segment of the North Anatolian Fault (NAF), which ruptured during the 1999 Mw7.4 Izmit earthquake, and caused tectonic loading of the fault segment in front of the Istanbul metropolitan area. In order to study gas seepage and seismic energy release along the NAF, a multiparametric benthic observatory (SN-4) was deployed in the gulf at the western end of the 1999 Izmit earthquake rupture, and operated for about 1 yr at 166 m water depth. The SN-4 payload included a three-component broad-band seismometer, as well as gas and oceanographic sensors. We analysed data collected continuously for 161 d in the first part of the experiment, from 2009 October to 2010 March. The main objective of our work was to verify whether tectonic deformation along the NAF could trigger methane seepage. For this reason, we considered only local seismicity, that is, within 100 km from the station. No significant (ML ≥ 3.6) local earthquakes occurred during this period; on the other hand, the seismometer recorded high-frequency SDEs (short duration events), which are not related to seismicity but to abrupt increases of dissolved methane concentration in the sea water that we called MPEs (methane peak events). Acquisition of current velocity, dissolved oxygen, turbidity, temperature and salinity, allowed us to analyse the local oceanographic setting during each event, and correlate SDEs to episodic gas discharges from the seabed. We noted that MPEs are the result of such gas releases, but are detected only under favourable oceanographic conditions. This stresses the importance of collecting long-term multiparametric time-series to address complex phenomena such as gas and seismic energy release at the seafloor. Results from the SN-4 experiment in the Sea of Marmara suggest that neither low-magnitude local seismicity, nor regional events affect intensity and frequency of gas flows from the seafloor.

Description: Published

Description: 850-866

Description: 1T. Geodinamica e interno della Terra

Description: 3A. Ambiente Marino

Description: 7A. Geofisica di esplorazione

Description: JCR Journal

Description: restricted

Description: Background: The determination of the plant-induced Fe-isotopic fractionation is a promising tool to better quantify their role in the geochemical Fe cycle and possibly to identify the physiological mechanisms of Fe uptake and translocation in plants. Here we explore the isotope fractionation caused by translocation of Fe during growth of bean and oat as representatives of strategy I and II plants. Methods: Plants were grown on a nutrient solution supplemented with Fe(III)-EDTA and harvested at three different ages. We used the technique of multi-collector ICP-MS to resolve the small differences in the stable iron isotope compositions of plants. Results: Total bean plants, regardless of their age, were found to be enriched in the light iron isotopes by -1.2‰ relative to the growth solution throughout. During growth plants internally redistributed isotopes where young leaves increasingly accumulated the lighter isotopes whereas older leaves and the total roots were simultaneously depleted in light iron isotopes. Oat plants were also enriched in the light iron isotopes but during growth the initial isotope ratio maintained in all organs at all growth stages. Conclusions: We conclude that isotope fractionation in bean as a representative of strategy I plants is a result of translocation or re-translocation processes. Furthermore we assume that both uptake and translocation of Fe in oat maintains the irons’ ferric state, or that Fe is always bound to high-mass ligands, so that isotope fractionation is virtually absent in these plants. However, in contrast to our previous study in which strategy II plants were grown on soil substrate, oat plants grown on Fe(III)-EDTA contain iron that enriches 54Fe by 0.5 permil over 56Fe. A possible explanation for the enrichment is the prevalence of a constitutive reductive uptake mechanism of iron in the nutrient solution used which is non-deficient in iron.

Description: Based on cosmogenic 10Be and 26Al analyses in 15 individual detrital quartz pebbles (16e21 mm) and cosmogenic 10Be in amalgamated medium sand (0.25e0.50 mm), all collected from the outlet of the upper Gaub River catchment in Namibia, quartz pebbles yield a substantially lower average denudation rate than those yielded by the amalgamated sand sample. 10Be and 26Al concentrations in the 15 indi- Accepted 9 April 2012 Available online xxx vidual pebbles span nearly two orders of magnitude (0.22 ± 0.01 to 20.74 ± 0.52 x 10 6 10 Be atoms g-1 and 1.35 ± 0.09 to 72.76 ± 2.04 x 106 26Al atoms g-1, respectively) and yield average denudation rates of w0.7 m Myr-1 (10Be) and w0.9 m Myr-1 (26Al). In contrast, the amalgamated sand yields an average Keywords: Beryllium-10 10Be concentration of 0.77 ± 0.03 x 106 atoms g-1, and an associated mean denudation rate of Aluminium-26 Neon-21 Cosmogenic nuclide Grain size bias Namibia 9.6 ± 1.1 m Myr-1, an order of magnitude greater than the rates obtained for the amalgamated pebbles. The inconsistency between the 10Be and 26Al in the pebbles and the 10Be in the amalgamated sand is likely due to the combined effect of differential sediment sourcing and longer sediment transport times for the pebbles compared to the sand-sized grains. The amalgamated sands leaving the catchment are an aggregate of grains originating from all quartz-bearing rocks in all parts of the catchment. Thus, the cosmogenic nuclide inventories of these sands record the overall average lowering rate of the landscape. The pebbles originate from quartz vein outcrops throughout the catchment, and the episodic erosion of the latter means that the pebbles will have higher nuclide inventories than the surrounding bedrock and soil, and therefore also higher than the amalgamated sand grains. The order-of-magnitude grain size bias observed in the Gaub has important implications for using cosmogenic nuclide abundances in deposi- tional surfaces because in arid environments, akin to our study catchment, pebble-sized clasts yield substantially underestimated palaeo-denudation rates. Our results highlight the importance of carefully considering geomorphology and grain size when interpreting cosmogenic nuclide data in depositional surfaces.

Description: Working plan

Description: Supported by IOC for IODE.

Description: Document available in English.

Description: Unpublished

Description: The Amazonian rainforest is arguably the most species-rich terrestrial ecosystem in the world, yet the timing of the origin and volutionary causes of this diversity are a matter of debate. We review the geologic and phylogenetic evidence from Amazonia and compare it with uplift records from the Andes. This uplift and its effect on regional climate fundamentally changed the Amazonian landscape by reconfiguring drainage patterns and creating a vast influx of sediments into the basin. On this “Andean” substrate, a region-wide edaphic mosaic developed that became extremely rich in species, particularly in Western Amazonia. We show that Andean uplift was crucial for the evolution of Amazonian landscapes and ecosystems, and that current biodiversity patterns are rooted deep in the pre-Quaternary.

Description: Frozen sediments from three cores bored in the permafrost surrounding the El’gygytgyn Impact Crater Lake have been studied for pollen, non-pollen palynomorphs, plant macrofossils and rhizopods. The palynological study of these cores contributes to a higher resolution of time intervals presented in a poor temporal resolution in the lacustrine sediments; namely the Allerød and succeeding periods. Moreover, the permafrost records better reflect local environmental changes, allowing a more reliable reconstruction of the local paleoenvironments. The new data confirm that shrub tundra with dwarf birch, shrub alder and willow dominated the lake surroundings during the Allerød warming. Younger Dryas pollen assemblages reflect abrupt changes to grass-sedge-herb dominated environments reflecting significantly drier and cooler climate. Low shrub tundra with dwarf birch and willow dominate the lake vicinity at the onset of the Holocene. The find of larch seeds indicate its local presence around 11 000 cal yr BP and, thus a northward shift of treeline by about 100 km during the early Holocene thermal optimum. Forest tundra with larch and shrub alder stands grew in the area during the early Holocene. After ca. 3500 cal yr BP similar-to-modern plant communities became common in the lake vicinity.

Description: The combination of permafrost history and dynamics, lake level changesRussian Arctic. The purpose of this study is to propose a depositional framework based on analyses of the core strata from the lake margin and historical reconstructions from various studies at the site. A sedimentological program has been conducted using frozen core samples from the 141.5m long El’gygytgyn 5011-3 permafrost well. The drill site is located in sedimentary permafrost west of the lake that partly fills the El’gygytgyn Crater. The total core sequence is interpreted as strata building up a progradational alluvial fan delta. Four macroscopically distinct sedimentary units are identified. Unit 1 (141.5–117.0 m) is comprised of ice-cemented, matrix-supported sandy gravel and intercalated sandy layers. Sandy layers represent sediments which rained out as particles in the deeper part of the water column under highly energetic conditions. Unit 2 (117.0–24.25 m) is dominated by ice-cemented, matrix-supported sandy gravel with individual gravel layers. Most of the Unit 2 diamicton is understood to result from alluvial wash and subsequent gravitational sliding of coarse-grained (sandy gravel) material on the basin slope. Unit 3 (24.25–8.5 m) has icecemented, matrix-supported sandy gravel that is interrupted by sand beds. These sandy beds are associated with flooding events and represent near-shore sandy shoals. Unit 4 (8.5–0.0 m) is ice-cemented, matrix-supported sandy gravel with varying ice content, mostly higher than below. It consists of slope material and creek fill deposits. The uppermost metre is the active layer (i.e. the top layer of soil with seasonal freeze and thaw) into which modern soil organic matter has been incorporated. The nature of the progradational sediment transport taking place from the western and northern crater margins may be related to the complementary occurrence of frequent turbiditic layers in the central lake basin, as is known from the lake sediment record. Slope processes such as gravitational sliding and sheet flooding occur especially during spring melt and promote mass wasting into the basin. Tectonics are inferred to have initiated the fan accumulation in the first place and possibly the off-centre displacement of the crater lake.

Description: 〈jats:p〉Abstract. The spatial and temporal variability of a low-centred polygon on the eastern floodplain area of the lower Anabar River (72.070° N, 113.921° E, northern Yakutia, Siberia) has been investigated using a multi-method approach. The present-day vegetation in each square metre was analysed revealing a community of Larix shrubby Betula and Salix on the polygon rim, a dominance of Carex and Andromeda polifolia in the rim-to-pond transition zone, and a predominantly monospecific Scorpidium scorpioides coverage within the pond. The TOC content, TOC/TN ratio, grain-size, vascular plant macrofossils, moss remains, diatoms, and pollen were analysed for two vertical sections and a sediment core from a transect across the polygon. Radiocarbon dating indicates that the formation of the polygon started at least 1500 yr ago; the general positions of the pond and rim have not changed since that time. Two types of pond vegetation were identified, indicating two contrasting development stages of the polygon. The first was a well-established moss association dominated by submerged or floating Scorpidium scorpioides and/or Drepanocladus spp. and overgrown by epiphytic diatoms such as Tabellaria flocculosa and Eunotia taxa. This stage coincides temporally with a period in which the polygon was only drained by lateral subsurface water flow, as indicated by mixed grain sizes. A different moss association occurred during times of repeated river flooding (indicated by homogeneous medium-grained sand that probably accumulated during the annual spring snow melt), characterized by an abundance of Meesia triquetra and a dominance of benthic diatoms (e.g. Navicula vulpina), indicative of a relatively high pH and a high tolerance of disturbance. A comparison of the local polygon vegetation (inferred from moss and macrofossil spectra) with the regional vegetation (inferred from pollen spectra) indicated that the moss association with Scorpidium scorpioides became established during relatively favourable climatic conditions while the association dominated by Meesia triquetra occurred during periods of harsh climatic conditions. Our study revealed a strong riverine influence (in addition to climatic influences) on polygon development and the type of peat accumulated. 〈/jats:p〉

Description: Many database systems share a need for large amounts of fast storage. However, economies of scale limit the utility of extending a single machine with an arbitrary amount of memory. The recent broad availability of the zero-copy data transfer protocol RDMA over low-latency and high-throughput network connections such as InfiniBand prompts us to revisit the long-proposed usage of memory provided by remote machines. In this paper, we present a solution to make use of remote memory without manipulation of the operating system, and investigate the impact on database performance.

Description: The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habitat specialists and only dominant in one or two regions of the basin. We discuss some implications of the finding that a small group of species—less diverse than the North American tree flora—accounts for half of the world’s most diverse tree community.

Description: In Noordwest-Europa is de taxonomie van bramen (Rubus L. subgenus Rubus) goed op orde en de verspreiding van bramen in de verschillende landen goed bekend dankzij herbarium- en veldonderzoek vanaf de jaren 1970. De meeste soorten zijn gestabileerde apomicten die zonder bevruchting zaad vormen. De nakomelingen van een zich apomictisch voortplantende braam zijn hierdoor genetisch gelijk aan de moederplant. In Nederland dateert onderzoek aan bramen pas van na 1900 met een actieve periode na de Tweede Wereldoorlog. Dit resulteerde in 1956 in de Rubi Neerlandici door W. Beijerinck, een overzicht gebaseerd op de kunstmatig soortsopvatting van H. Sudre (Rubi Europae; 1908–1913). Het moderne, op typemateriaal en veldwerk gebaseerde onderzoek startte begin jaren 1970 en resulteerde in de decennia erna tot de herkenning en beschrijving van tal van nieuwe regionale soorten en nieuwe namen voor verkeerd geïnterpreteerde soorten. Door de meeste Europese bramendeskundigen wordt een soortsopvatting gehanteerd die inhoudt dat taxa met een areaaldiameter kleiner dan 50 km niet worden beschreven als soort. Deze opvatting wordt ook door ons gehanteerd. Op de naamlijst van Nederlandse bramen van het subgenus Rubus staan 191 soorten verdeeld over 4 secties: Rubus (Zwarte braam; ‘Rubus fruticosus agg.’; 147 soorten), Corylifolii Lindl. (Wasbraam; ‘Rubus corylifolius agg.’; 34 soorten), Caesii Lej. & Courtois (Dauwbraam; 2 soorten) en Subidaei (Focke) A.Beek (Purperbraam; 8 soorten). De laatste sectie omvat gestabiliseerde soorten met R. idaeus L. (Framboos) als voorouder. Nomenclatorische aspecten van de Nederlandse taxa en de beschrijving van enkele nieuwe wasbramen zijn in begeleidende artikelen ondergebracht. Alle taxa – secties, subsecties, series en soorten – zijn voorzien van Nederlandse namen. Aangezien areaalgrootte een belangrijke rol speelt in de taxonomie, is elke soort toegekend aan een areaalcategorie: W1 (zeer wijdverbreid; areaaldiameter 〉1500 km), W2 (wijdverbreid; idem 500–1500 km), R1 (bovenregionaal; idem 250–500 km) of R2 (regionaal; idem 50–250 km). Van de Nederlandse bramen hebben 97 soorten (51%) een regionale verspreiding; slechts 32 soorten (17%) zijn zeer wijdverbreid. Alle digitaal beschikbare verspreidingsgegevens van soorten uit het subgenus Rubus (excl. R. caesius L.) zijn samengebracht in een database, in totaal ruim 43.000 records waarvan 37.000 met een nauwkeurigheid op km-hokniveau of beter. Van alle soorten (excl. Rubus caesius) is de landelijke zeldzaamheid bepaald op grond van Rode Lijst-criteria. Bijna 80 soorten zijn landelijk zeer zeldzaam, 60 zeldzaam, 25 vrij zeldzaam en ongeveer 20 vrij algemeen of algemeen. Zeer algemene soorten ontbreken, wat niet alleen heeft te maken met het hoge aandeel regionale soorten, maar ook met het feit dat in de klei- en veengebieden zeer weinig bramen voorkomen. De regionale verspreiding wordt per soort gegeven als percentage van het aantal uurhokken per floradistrict. Hotspots van soortenrijkdom met meer dan 40 soorten per uurhok liggen in oude boslandschappen in het Rijk van Nijmegen, de Liemers, de Oude IJsselstreek en aangrenzende Veluwezoom en de omgeving van Winterswijk (Achterhoek), Epen-Vijlen (Zuid Limburg) en Oldenzaal (Twente). De regionale soorten dragen sterk bij aan de identiteit van de regio’s. De relatief grote landelijke soortenrijkdom met regionale hotspots onderstreept de ligging van ons land in het centrum van de (sub)atlantische bramendiversiteit in Europa. The taxonomy and distribution of brambles (Rubus L. subgenus Rubus) are well-known in northwestern Europe due to herbarium studies and extensive field work from the 1970s onwards. Most brambles are stabilized apomictic species that form fruits without prior fertilization. Therefore, offspring is genetically identical with the mother plant. In the Netherlands, the study of brambles did not start until 1900, with a relatively active period occuring after World War II. This resulted in the publication of Rubi Neerlandici by W. Beijerinck in 1956, an overview based on the artificial species circumscription of H. Sudre (Rubi Europae; 1908–1913). Modern research, based on the study of type material supplemented with field work began in the 1970s and lead to the recognition of several newly described regional species as well as new names for misapplied species. Most bramble experts in Europe agree on a species circumscription that includes a geographic constraint: taxa with a range less than 50 km in diameter are not described as species. We adhere to this view as well. The Dutch checklist of subgenus Rubus comprises 191 species in 4 sections: Rubus (‘Rubus fruticosus agg.’; 147 species), Corylifolii Lindl. (‘Rubus corylifolius agg.’; 34 species), Caesii Lej. & Courtois (2 species) and Subidaei (Focke) A.Beek (8 species). The latter section includes stabilized species with Rubus idaeus L. as an ancestor. Nomenclatural aspects of the Dutch taxa and the description of some new Corylifolii taxa are dealt with in accompanying papers. All taxa on the checklist are provided with Dutch names, including sections, subsections and series. Since range size is taxonomically important, this feature has been classified and assigned to each species as W1 (very widespread; range diameter 〉1500 km), W2 (widespread; 500–1500 km), R1 (supraregional; 250–500 km) or R2 (regional; 50–250 km). The Dutch checklist contains 97 regional species (51%); only 32 species (17%) are very widespread. All digitally available distribution data for species of Rubus subgenus Rubus (excluding Rubus caesius L.) have been merged into a database, currently comprising about 43,000 records, including 37,000 with an accuracy of one kilometer or better. National rarity of species (Rubus caesius excluded) has been coded according to Dutch Red List criteria based on the number of occupied 5×5 km-squares. Almost 80 species are nationally very rare, 60 rare, 25 rather rare and about 20 rather common or common. Very common species are absent from the section Rubus, which is not only caused by the large proportion of regional species, but also by the low frequency of brambles on clay and peat soils in the western and northern parts of the country. Regional occurrence is expressed as percentage occupied relative to the total number of 5×5 km-squares for each flora district. Hotspots of species richness with more than 40 species per 5×5 km-square occur in old woodland landscapes in physiogeographic gradients with sandy and loamy soils. The national species richness in a European context, the high numbers of regional species, and the occurrence of hotspots of bramble diversity emphasize the central position of the Netherlands within the (sub) atlantic range of brambles in Europe.

Description: Ice thickness data over much of East Antarctica are sparse and irregularly distributed. This poses difficulties for reconstructing the homogeneous coverage needed to properly assess underlying sub-glacial morphology and fundamental geometric constraints on sea level rise. Here we introduce a new physically-based ice thickness interpolation scheme and apply this to existing ice thickness data in the Aurora Subglacial Basin region. The skill and robustness of the new reconstruction is demonstrated by comparison with new data from the ICECAP project. The interpolated morphology shows an extensive marine-based ice sheet, with considerably more area below sea-level than shown by prior studies. It also shows deep features connecting the coastal grounding zone with the deepest regions in the interior. This has implications for ice sheet response to a warming ocean and underscores the importance of obtaining additional high resolution data in these marginal zones for modelling ice sheet evolution.

Description: Published

Description: 551-560

Description: 3.8. Geofisica per l'ambiente

Description: JCR Journal

Description: open

Description: We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60 S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1) in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1. In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved datacoverage has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km3) and its potential contribution to sea-level rise (58 m) are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6% greater, the mean depth of the bed beneath the grounded ice sheet is 72m lower and the area of ice sheet grounded on bed below sea level is increased by 10 %. The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets.

Description: Published

Description: 375–393

Description: 1.8. Osservazioni di geofisica ambientale

Description: 3.8. Geofisica per l'ambiente

Description: JCR Journal

Description: open

Description: On two separate occasions during fieldwork in Semporna (eastern Sabah, Malaysia), sea anemones of the family Edwardsiidae were observed attempting to feed on the nudibranch species Nembrotha lineolata and Phyllidia ocellata. These are the first in situ observations of nudibranch predation by sea anemones. This new record is compared with known information on sea slug predators.

Description: We present a review of astrophorid species possessing calthrops megascleres as structural megascleres (including species with dichotriaene modifi cations, but excluding mesotriaene and trichotriaene bearing species). Radiating oxeas characteristic of most astrophorids are lacking in such sponges, but auxiliary oxeas are apparently present in some species. Th ese sponges are currently assigned to two families, Pachastrellidae with four nominal genera Dercitus, Stoeba, Dercitancorina, Halinastra (the latter two generally considered junior synonyms of Stoeba), and Calthropellidae with nominal genera Calthropella, Corticellopsis (usually considered a junior synonym), Pachataxa and Pachastrissa. Our review of many original specimens and extensive new material demonstrates the existence of considerable morphological similarity in megasclere shape and arrangement, and possible overlap of some microscleres of these sponges: pseudasters in Dercitus resembling euasters in Calthropella, ataxasters and other modifi ed types in Calthropellidae resembling rhabds in a species of Dercitus. Pachastrellid representatives are proposed to be united in a single genus Dercitus, recognizable as (dicho–)calthrops bearing sponges with sanidaster–like microrhabds. Th ree subgenera, Dercitus s.s., Stoeba and the revived Halinastra are distinguished to accommodate species groups sharing additional characters. Dercitancorina is merged with Dercitus (Stoeba), because the type species, D. lesinensis was found to be barely distinct from D. (S.) plicatus. Similarly, the calthropellid representatives are proposed to be united in a single genus Calthropella recognizable as calthrops bearing sponges with oxyasters. Th ree subgenera, Calthropella s.s., Pachataxa and Corticellopsis are distinguished to accommodate species groups sharing additional characters. Th e calthropellid genus Pachastrissa is considered a junior synonym of Calthropella s.s. because its type species, Pachastrella geodioides, is barely distinct from the type species of Calthropella, C. simplex. Two species previously assigned to Dercitus or Stoeba (Dercitus loricatus and Stoeba natalensis) are excluded from the genus Dercitus as they do not fi t with the emended and improved defi nition of the genus. One species assigned to Calthropella, C. digitata, is excluded from that genus and assigned to the ancorinid genus Stelletta. Based on the similarity of the megascleres and their structure-less arrangement, we predict that the two reviewed genera will be found to be closely related and eventually will need to be accomodated in a single family, but independent molecular evidence is awaited before changes in the family classifi cation, including a verdict on the validity of the family Calthropellidae, will be proposed. Our review included 38 valid species among which fourteen species and one subspecies appear to be new to science. Four of these were represented by insuffi cient material for a proper description, but the remaining ten are described as new species: Dercitus (Stoeba) senegalensis sp. n., Dercitus (Stoeba) verdensis sp. n., Dercitus (Stoeba) fi jiensis sp. n., Dercitus (Stoeba) bahamensis sp. n., Dercitus (Halinastra) berau sp. n., Dercitus (Halinastra) japonensis sp. n., Dercitus (Halinastra) arubensis sp. n., Dercitus (Halinastra) sibogae sp. n., Calthropella (Calthropella) xavierae sp. n., and Calthropella (Pachataxa) pyrifera sp. n. Th e new subspecies, Dercitus (Dercitus) bucklandi lusitanicus ssp. n. is described for southern East Atlantic populations of the nominal species. Several specimens assigned to existing species were found to be deviating to the extent that they are likely members of further undescribed species. Th ese are briefl y discussed to facilitate further studies of the diversity of the two genera. Species of both genera and the six subgenera, including deviating or insuffi ciently characterized specimens belonging to species not yet properly described, are keyed out. Distribution patterns are discussed.

Description: Sea urchins as broadcasting spawners, release their gametes into open water for fertilization, thus being particularly vulnerable to ocean acidification. In this study, we assessed the effects of different pH scenarios on fertilization success of Strongylocen- 5 trotus droebachiensis, collected at Spitsbergen, Arctic. We achieved acidification by bubbling CO2 into filtered seawater using partial pressures (pCO2) of 180, 380, 980, 1400 and 3000 μatm. Untreated filtered seawater was used as control. We recorded fertilization rates and diagnosed morphological aberrations after post-fertilization periods of 1 h and 3 h under different exposure conditions in experiments with and without 10 pre-incubation of the eggs prior to fertilization. In parallel, we conducted measurements of intracellular pH changes using BCECF/AM in unfertilized eggs exposed to a range of acidified seawater. We observed increasing rates of polyspermy in relation to higher seawater pCO2, which might be due to failures in the formation of the fertilization envelope. In addition, our experiments showed anomalies in fertilized eggs: incomplete 15 lifting-off of the fertilization envelope and blebs of the hyaline layer. Other drastic malformations consisted of constriction, extrusion, vacuolization or degeneration (observed as a gradient from the cortex to the central region of the cell) of the egg cytoplasm, and irregular cell divisions until 2- to 4-cell stages. The intracellular pH (pHi) decreased significantly from 1400 μatm on. All results indicate a decreasing fertilization success 20 at CO2 concentrations from 1400 μatm upwards. Exposure time to low pH might be a threatening factor for the cellular buffer capacity, viability, and development after fertilization.

Description: Future impacts of ocean acidification on reproduction of exposed marine organisms with consequences at the population level still have to be properly analyzed and understood. For fertilization, eggs of echinoderms are directly released into seawater where the acrosome reaction takes place. Therefore, gametes are directly exposed unprotected to the detrimental conditions of an acidified environment. There is evidence that internal pH levels of cells change within 15-30 min conditioned by the external pH to which the eggs are exposed. Internal pH of the eggs plays an important role in the metabolic functionality of the signaling pathways and enzymatic activations induced by the contact with the sperm. These processes prohibit polyspermy and initiate normal embryonic development. We selected a species of sea urchin from the Arctic (Strongylocentrotus droebachiensis) to study the effect of sea water acidification on fertilization success. First results on fertilization experiments under various pH conditions (180 µatm, 380 µatm, 980 µatm, 1400 µatm and 3000 µatm) at natural temperatures and with two different approaches (with or without pre-incubation of the eggs) will be presented. Dramatic effects on fertilization success and embryonic development were identified under prognostic future pH conditions. We will discuss the vulnerability of the process of fertilization under past, present and future conditions.

Description: Fertilization depends on distribution and aggregation patterns of sea urchins which influence gamete contact time and may potentially enhance their vulnerability to ocean acidification. In this study, we conducted fertilization experiments to assess the effects of selected pH scenarios on fertilization success of Strongylocentrotus droebachiensis, from Spitsbergen, Arctic. Acidification was achieved by aerating seawater with different CO2 partial pressures to represent preindustrial and present conditions (measured*180–425 latm) and future acidification scenarios (*550–800, *1,300, *2,000 latm). Fertilization success was defined as the proportion of successful/unsuccessful fertilizations per treatment; eggs were classified according to features of their fertilization envelope (FE), hyaline layer (HL) and achievement of cellular division. The diagnostic findings of specific pathological aberrations were described in detail. We additionally measured intracellular pH changes in unfertilized eggs exposed for 1 h to selected acidification treatments using BCECF/AM. We conclude that (a) acidified conditions increase the proportion of eggs that failed fertilization, (b) acidification may increase the risk of polyspermy due to failures in the FE formation supported by the occasional observation ofmultiple sperms in the perivitelline space and (c) irregular formation of the embryo may arise due to impaired formation of the HL. The decrease in fertilization success could be also related to the observed changes in intracellular pH at pCO2 * 1,000 latm or higher.

Description: There are ten known species of Amorphophallus in the Philippines, and an eleventh is herein described and named as Amorphophallus adamsensis. It resembles A. dactylifer and A. rostratus. Diagnostic characters of this new species are provided.

Description: We describe and illustrate Paepalanthus aleurophyllus (Eriocaulaceae, Paepalanthoideae). The species is narrowly distributed, restricted to the Pico do Itambé in Minas Gerais, Brazil. Detailed comparisons are made with P. diplobetor and P. ciliolatus. Paepalanthus aleurophyllus is distinguished by its densely ciliated leaves with dolabriform to fusiform trichomes in the adaxial leaf surface, conspicuous venation on the abaxial leaf surface, trichomes between the scape ribs, general habit, and other floral features. We provide detailed line drawings and commentaries on distribution, ecology, and conservation.

Description: Hieracium L. (Havikskruid) is een van de lastigste geslachten van de Nederlandse flora en de determinatie van de taxa binnen Hieracium subgen. Hieracium is erg lastig. Van oudsher worden twee systemen gehanteerd om de variatie binnen het subgenus te ordenen: met behulp van hoofden tussensoorten, waarbinnen talloze ondersoorten, variëteiten en forma’s worden onderscheiden (Midden-Europese systeem), en door het onderscheiden van elke apomictische voortplantingseenheid als zelfstandige soort, die worden samengevat in secties en series (Noord-Europese systeem). Van Soest, die in de jaren 20 en 30 van de 20e eeuw aan Hieracium werkte, gebruikte het MiddenEuropese systeem, maar het Noord-Europese systeem sluit beter aan bij de biologische structuur van het genus. De taxa die thans worden onderscheiden in Heukels’ Flora zijn de hoofdsoorten die Van Soest onderscheidde en deze komen overeen met secties in het Noord-Europese systeem. Omdat veelvuldig fouten worden gemaakt met de determinatie van havikskruiden wordt een nieuwe sleutel van de secties gepresenteerd. Samenvattend wordt een overzicht gegeven van de secties van het geslacht in Nederland, met een korte impressie van het aantal soorten dat is aangetroffen. Hieracium L. (Hawkweed) is one of the most diverse and challenging genera in the Dutch flora. Historically, two systems were developed to address variation within Hieracium subgen. Hieracium: recognition of numerous subspecies, varieties, and forms with the help of ‘Hauptarten’ and ‘Zwischenarten’ (Central-European system), and grouping in sections and series of every apomictic progenitive unit as a separate species (North-European system). The Central-European system has been used in the Netherlands since Van Soest introduced it in the 1920s and 1930s. The taxa in the recent Heukels’ Flora6 are the ‘Hauptarten’ as recognised by Van Soest and they correspond well with the sections of the North-European system. Because Hieracium species are frequently misidentified, this paper presents a new key to the sections of Hieracium subgen. Hieracium. In addition, an overview is provided of the sections of Hieracium subgen. Hieracium in the Netherlands, including the number of species in each sections.

Description: Magnolia sulawesiana is described as new species and a modified key of Magnolia subsect. Elmerrillia is included. In addition, a new key of the ten Magnolia species occurring in Sulawesi is provided based on vegetative characters for easy identification in the field.

Description: Mapania sapuaniana, a spectacular new sedge species from Lanjak Entimau, Sarawak, is described and illustrated. It is closely related to M. richardsii and M. borneensis but differs in having broad leaves with a distinct pseudopetiole, reddish purple or maroon coloration on the underside of the leaf and petiole and an inflorescence composed of several spikes.

Description: Magnolia biondii var. purpurascens var. nov. and Magnolia cylindrica var. purpurascens var. nov. (Magnoliaceae) are described as two new varieties endemic to China. Magnolia biondii var. purpurascens is mainly restricted to forests of Shaanxi and SE Gansu provinces. It differs from the typical variety, M. biondii var. biondii, in the dense indumentum of white hairs on twigs and the cup-shaped purplish red flowers. Magnolia cylindrica var. purpurascens occurs in secondary forests of Jingning and Songyang counties of southern Zhejiang province. It differs from the typical variety, M. cylindrica var. cylindrica, in the cup-shaped flowers of purplish red colour. The two new varieties are distinct in their distributions in both cases but share the chromosome numbers with their typical varieties. Magnolia biondii var. purpurascens is a diploid with 2n = 38, whereas M. cylindrica var. purpurascens is a tetraploid with 2n = 76.

Description: β-tubulin (benA, tub-2) and calmodulin (caM) are crucial genes in the taxonomy of Aspergillus section Nigri. Widely used β-tubulin primers are not specific for the benA gene for some taxa and preferentially amplify the tubC paralogue. Sequences of the tubC paralogue are widely combined with benA sequences in recent taxonomical works as well as other works, resulting in incongruent trees. In this study we newly provide benA sequences for several ex-type strains, which were characterised using the tubC gene only. We designed a highly specific forward primer to benA designated Ben2f for use in Aspergillus section Nigri, and tested specificity of numerous primer combinations to β-tubulin paralogs. The primer pairs with the highest specificity to the benA gene and functional across species in section Nigri includes Ben2f/Bt2b, Ben2f/T22 and T10/T22. We also provide tools based on codon usage bias analysis that reliably distinguish both paralogues. Exon/intron arrangement is the next distinctive characteristic, although this tool is not valid outside section Nigri. The species identity of taxa from the ʽA. aculeatus cladeʼ used in previous molecular studies was revised using combined molecular data (ITS, benA, caM). These data together with two different PCR-fingerprinting methods indicated that A. japonicus should be treated as a synonym of A. violaceofuscus. Similarly, A. fijiensis is reduced to synonymy with A. brunneoviolaceus.

Description: I made use of the known dates of reclamation (and of afforestations) in the IJsselmeerpolders in The Netherlands to assess evolutionary adaptation in Cepaea nemoralis. At 12 localities (three in each polder), I sampled a total of 4390 adult individuals in paired open and shaded habitats, on average 233m apart, and scored these for genetic shell colour polymorphisms. The results show (highly) significant differentiation at most localities, although the genes involved differed per locality. Overall, though, populations in shaded habitats had evolved towards darker shells than those in adjacent open habitats, whereas a 'Cain & Sheppard' diagram (proportion yellow shells plotted against ‘effectively unbanded’ shells) failed to reveal a clear pattern. This might suggest that thermal selection is more important than visual selection in generating this pattern. Trait differentiation, regardless of whether they were plotted against polder age or habitat age, showed a linear increase of differentiation with time, corresponding to a mean rate of trait evolution of 15–31 kilodarwin. In conclusion, C. nemoralis is capable of rapid and considerable evolutionary differentiation over 1–25 snail generations, though equilibrium may be reached only at longer time scales.

Description: Recently, N. baramensis and N. rafflesiana var. subglandulosa were described from Borneo as new taxa closely related to N. rafflesiana. However, comparison of new collections made in Borneo with N. baramensis and N. rafflesiana var. subglandulosa indicated a synonymy. Furthermore, they were identical to N. hemsleyana, an older taxon formerly treated as synonym of N. rafflesiana. Acknowledging the taxonomic differences to N. rafflesiana, the name N. hemsleyana is reinstated following the priority rule. New evidence is presented that strengthens the interpretation to split N. rafflesiana and N. hemsleyana.

Description: Fragmentation of the former broadly circumscribed genus Acacia (Leguminosae: Mimosoideae) necessitates combinations in Senegalia (syn. Acacia subg. Aculeiferum) and Vachellia (syn. former Acacia subg. Acacia) for the following 40 taxa that are recorded for the region encompassed by Southeast Asia and China. Senegalia andamanica, S. borneensis, S. caesia, S. comosa, S. delavayi, S. delavayi var. kunmingensis, S. donnaiensis, S. gageana, S. intsia, S. kekapur, S. kostermansii, S. meeboldii, S. megaladena, S. megaladena var. garrettii, S. megaladena var. indochinensis, S. merrillii, S. palawanensis, S. pennata subsp. hainanensis, S. pennata subsp. insuavis, S. pluricapitata, S. pluriglandulosa, S. pruinescens, S. pseudointsia, S. sulitii, S. tawitawiensis, S. teniana, S. thailandica, S. tonkinensis, S. torta, S. verheijenii, S. vietnamensis and S. yunnanensis. Vachellia harmandiana, V. inopinata, V. kingii, V. leucophloea, V. leucophloea var. microcephala, V. myaingii, V. siamensis (syn. Acacia craibii) and V. tomentosa. Senegalia rugata replaces the well-known name Acacia concinna. There are four doubtful names for the region, namely, Acacia brunnescens, A. microcephala, A. obcordata and A. pseudoarabica.