Real-time setup to measure radon emission during rock deformation. Implications for geochemical surveillance

Laboratory experiments can represent a valid approach to unravel the complex interplay between the geochemical behaviour of radon and rock deformation mechanisms. In light of this, we present a new real-time experimental setup for analysing in continuum the alpha-emitting 222Rn and 220Rn daughters over variable stress–strain regimes. The most innovative segment of this setup consists of the radon accumulation chamber obtained from a tough and durable material that can host large cylindrical rock samples. The accumulation chamber is connected, in a closed-loop configuration, to a gas-drying unit and to a RAD7 radon monitor. A recirculating pump moves the gas from the rock sample to a solid-state detector for alpha counting of radon and thoron progeny. The measured radon signal is enhanced by surrounding the accumulation chamber with a digitally controlled heating belt. As the temperature is increased, the number of effective collisions of radon atoms increases favouring the diffusion of radon through the material and reducing the analytical uncertainty. The accumulation chamber containing the sample is then placed into a uniaxial testing apparatus where the axial deformation is measured throughout a linear variable displacement transducer. A dedicated software allows obtaining a variety of stress–strain regimes from fast deformation rates to long-term creep tests. Experiments conducted with this new real-time setup have important ramifications for the interpretation of geochemical anomalies recorded prior to volcanic eruptions or earthquakes

Testing the Properties of Radon Barrier Materials and Home Ventilation to Mitigate Indoor Radon

Indoor radon is the second cause of lung cancer. Mitigation strategies are based on (i) building protection with radon barrier materials, (ii) increasing home ventilation or (iii) room pressurization. A scale model room created with a porous ignimbrite rich in radon precursors was used as an analogue to test the indoor radon reduction ability of various radon barrier materials in a real room. The properties of these materials were tested with and without room pressurization by introducing outdoor air at different flow rates. The best materials reduced indoor radon up to 80% and, when the highest pressurization was applied, to 93%

Deliverable # 3.01.1 Technical report illustrating the results obtained in the Crotone Peninsula based on geological and InSAR data

This work was aimed at collecting data to estimating the rate of uplift over several temporal scales. The analysis includes a very short-term analysis (tens of years) of InSAR data, a middle-term analysis of Holocene geological data, and a long-term analysis of Middle-Late Pleistocene geological data. After a preliminary reconnaissance in a large area, all final datasets focus strictly on the area of the Crotone Peninsula. The techniques applied span from Small Baseline Subset Interferometric SAR, to classic geomorphic and stratigraphic analysis aided by radiocarbon and U/Th dating.Agreement INGV-DPC 2007-2009 Project S1: Analysis of the seismic potential in Italy for the evaluation of the seismic hazardPublished3.2. Tettonica attiva4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionaleope

Deliverable # 3.01.1 Technical report illustrating the results obtained in the Crotone Peninsula based on geological and InSAR data

This work was aimed at collecting data to estimating the rate of uplift over several temporal scales. The analysis includes a very short-term analysis (tens of years) of InSAR data, a middle-term analysis of Holocene geological data, and a long-term analysis of Middle-Late Pleistocene geological data. After a preliminary reconnaissance in a large area, all final datasets focus strictly on the area of the Crotone Peninsula. The techniques applied span from Small Baseline Subset Interferometric SAR, to classic geomorphic and stratigraphic analysis aided by radiocarbon and U/Th dating

Upper Pleistocene deposits and karst features in the littoral landscape of Mallorca Island (Western Mediterranean): a field trip

Abstract not availabl

Hazardous gas emissions from the flanks of the quiescent Colli Albani volcano (Rome, Italy)

Gas hazard was evaluated in the three most important cold gas emission zones on the flanks of the quiescent Colli Albani volcano. These zones are located above structural highs of the buried carbonate basement which represents the main regional aquifer and the main reservoir for gas rising from depth. All extensional faults affecting the limestone reservoir represent leaking pathways along which gas rises to the surface and locally accumulates in shallow permeable horizons forming pressurized pockets that may produce gas blowout when reached by wells. The gas, mainly composed by CO2 (>90 vol.%), contains appreciable quantities of H2S (0.35-6 vol.%), and both represent a potentially high local hazard. Both gases are denser than air and accumulate near ground where they may reach hazardous concentrations, and actually lethal accidents frequently occur to animals watering at local ponds. In order to evaluate the rate of degassing and the related hazard, CO2 and H2S diffuse soil flux surveys have been repeatedly carried out by accumulation chamber. The viscous gas flux of some important discrete emissions has been also evaluated and the CO2 and H2S air concentration measured by portable devises and by Tunable Diode Laser profiles. The minimum potential lethal concentration of the two gases (250 ppm for H2S and 8 vol.% for CO2) is 320 times higher for CO2, whereas the CO2/H2S concentration ratio in the emitted natural gas is significantly lower (15-159). This explains why H2S reaches hazardous, even lethal, concentrations more frequently than CO2. A relevant hazard exists for both gases in the depressed zones (channels, excavations) particularly in the non-windy early hours of the day

Exceptionally stable pre-industrial sea level inferred from the western Mediterranean Sea

An accurate record of pre-industrial (pre-1900 CE) sea level is necessary to place modern global mean sea-level rise in context with respect to natural variability. We present new results from precisely dated phreatic overgrowths on speleothems (POS) that preserve a detailed history of Late Holocene sea level. These data indicate that the largest sea-level jump occurred between 0.12 and 0.31 m (95% confidence) from 3.26 to 2.84 ka BP (2σ). Our results show that relative sea level stayed within 0.08 m (95% confidence) of pre-industrial levels from 2.84 ka BP to 1900 CE. This sea-level history is consistent with models of glacial isostatic adjustment that adopt a relatively weak upper mantle viscosity of ~1020 Pa s. Models indicate virtual certainty (> 0.999 probability) that rates of sea-level rise over the past 4 ka (including the 400-year jump) have not approached the global average since 1900 CE; therefore, recent sea-level rise cannot be explained by natural variability

Body Shape and Life Style of the Extinct Balearic Dormouse Hypnomys (Rodentia, Gliridae): New Evidence from the Study of Associated Skeletons

Hypnomys is a genus of Gliridae (Rodentia) that occurred in the Balearic Islands until Late Holocene. Recent finding of a complete skeleton of the chronospecies H. morpheus (Late Pleistocene-Early Holocene) and two articulated skeletons of H. cf. onicensis (Late Pliocene) allowed the inference of body size and the calculation of several postcranial indexes. We also performed a Factorial Discriminant Analysis (FDA) in order to evaluate locomotory behaviour and body shape of the taxa. Using allometric models based on skull and tooth measurements, we calculated a body weight between 173 and 284 g for H. morpheus, and direct measurements of articulated skeletons yielded a Head and Body Length (HBL) of 179 mm and a Total Body Length of 295 mm for this species. In addition to the generally higher robustness of postcranial bones already recorded by previous authors, H. morpheus, similar to Canariomys tamarani, another extinct island species, displayed elongated zygopodium bones of the limbs and a wider distal humerus and femur than in an extant related taxon, Eliomys quercinus. Indexes indicated that Hypnomys was more terrestrial and had greater fossorial abilities than E. quercinus. This was also corroborated by a Discriminant Analysis, although no clear additional inference of locomotory abilities could be calculated

Uranium-series and trapped charge dating of tufa and travertines

Speleothems, fresh-water tufa and travertines are generally dated using methods based on uranium-series disequilibria, but also on cosmogenic radionuclides and radiation damage. The basic theory of these methods is introduced and related applications in the study of continental carbonates are shown with examples derived from recent research. U-Th is the most popular method and is based on the measurement of 230Th formed in situ by radioactive decay of uranium (234U and 238U) co-precipitated with CaCO3. In the absence of detrital minerals (see for example pure speleothems) the extent to which the 230Th/234U activity ratio has returned towards unity is a function of time, taking into account also the state of disequilibrium between 234U and 238U. Tufa and travertines, however, are impure mixtures of calcium carbonate and incorporated detrital minerals and deserve the recourse to specific correction schemes to determine the authigenic radionuclide component and thus a fitting age. The method extends back to at least 350,000 years. The disequilibria between other parent-daughter pairs in 238U and 235U decay chains (namely, 234U/238U, 231Pa/235U, 226Ra/230Th) are also used in carbonate dating. 234U/238U method can be applied to dating carbonates as old as 1.25 Ma, assuming that the uranium activity ratio in the parent fluids has remained constant over time. 226Ra/230Th method is used to date continental carbonates younger than 8 ka, presupposing that 226Ra/230Th initial activity ratio can be determined on present-day deposition. Recently, the use of the classic U-Pb method has been extended to speleothems dating, opening new perspectives on the study of older speleothems, not datable using standard U-series methods. The use of radiocarbon dating in carbonate chronology is considered problematic, principally because of potential variability in the contribution of “dead carbon” from the host limestone. Actually, precipitating waters may contain a proportion of carbon inherited from the dissolution of a 14C-free carbonate component in the bedrock. Another problem could arise from the contamination of the material with younger carbon from soil organic matter that might be deposited in the original structure of porous carbonate. In addition to that, bomb-14C may affect modern precipitation, leading to an inconsistently too young age. Because of these problems, relatively few speleothem chronologies are based on 14C ages. Radiation damage dating methods (electron spin resonance, thermoluminescence, optical stimulated luminescence) are based on the time-dependent accumulation of electrons in the crystal lattice of certain common minerals, acting as natural radiation dosimeters. Assuming a constant radiation dose, the extent of trapped electrons is proportional to the accumulated radiation and to the time elapsed since a “zeroing” event. Unfortunately, not all the samples are suited for radiation damage dating: indeed, the presence of cationic impurities such as Mn2+, Fe2+, or Fe3+, humic acids (organic matter), can mask the signal of interest, or interfere with it. These methods can be applied to date materials ranging in age from a few hundreds years to about a million year