Mapping the bedrock K2O, U and Th concentration in Italy - Towards the European Atlas of Natural Radiation

The Joint Research Center, the European Commission’s science and knowledge service, started the European Atlas of Natural Radiation project with the objective of gathering all the data related to natural radioactivity from the European countries. The estimate of the terrestrial natural radioactivity is one of the priority of the project and it includes the realisation of concentration maps of the radioactive elements naturally occurring in the environment, that are the elements of the U and Th families together with 40K. The aim of this work is to study the methodology to develop the first complete K2O, U and Th concentration maps of the bedrock in Italy through the creation of geological units identified on a pre-compiled basis and the collection of geochemical data from scientific literature. The geological units were determined based on litho-, chrono- and tectono-stratigraphic features of the bedrock. The dataset was created using global open-access database and peer-reviewed articles; the data, more than 15000 in total, was checked for outliers and representativeness and then studied with statistical analysis, in order to evaluate the methodology and to assign an average K2O, U and Th concentration to the geological units. The results confirm that the methodology is reliable and allows to create K2O, U and Th concentration maps at 1:1M scale. The main sources of errors come from the high lithological variability of the units, which implies a high variability in the distribution of the concentration values, and from the heterogeneity of the data coverage. Focusing on these problems, it’s still possible to improve the methodology, especially by increasing the amount of available geochemical data and, subsequently, by realising more accurate maps on a smaller scale

Fate of terrigenous organic carbon in muddy clinothems on continental shelves revealed by stratal geometries: Insight from the Adriatic sedimentary archive

Continental shelves host 90% of modern Organic Carbon (OC) burial and play a key role in the sequestration of terrigenous OC over geological timescales. The efficiency of OC burial in these systems, however, varies greatly depending on the duration of exposure to oxic-suboxic conditions during sediment transport. In this study, we use observations across a wide range of stratigraphic and sedimentological scales coupled with geochemistry data from muddy shelf deposits along the western Adriatic to investigate the relation between sediment transport and burial of terrigenous (land-derived) fraction of OC (OCTerr). Our analysis focused on the Little Ice Age (LIA, 1500-1850 CE) interval, which was characterized by wet, cold, and stormy weather conditions, before the time of widespread regulation and damming of rivers. On the Adriatic shelf, LIA deposits are organized as clinothem: strata that dip gently seawards. The LIA clinothem becomes progressively steeper and deeper from north to south. Basin-scale seismic-stratigraphic analysis and biogeochemical data show evidence of elongated stratal units associated with low OCTerr content in the northern sector of the LIA clinothem, whereas farther south, where clinoforms are steeper, the LIA clinothem exhibits wavy stratal units with limited cross-shelf continuity and high OCTerr concentrations. Based on these data we infer two contrasting scenarios for OCTerr deposition during the LIA: 1) protracted sediment redistribution under the influence of coastal currents with efficient OCTerr degradation prior to final burial in the northern sector; and (2) rapid deposition of OCTerr-rich event beds as a result of flood-driven hyperpycnal flows with limited dispersion across the shelf in the southern sector. The latter scenario of deposition resulted in scattered hot spots of OCTerr burial along the apparently homogeneous western Adriatic shelf deposit. Our work documents significant lateral variability of a fine-grained system in which hot spots of OCTerr can be preserved in scattered prodelta bedsets (<1 km in across-shelf lateral continuity) over a 600 km long shelf. Shelfal clinothems worldwide should not be considered as homogeneous pools of OCTerr because of the influence of river, storm, and oceanic currents

The first version of the Pan-European Indoor Radon Map

A hypothetical Pan-European Indoor Radon Map has been developed using summary statistics estimated from 1.2 million indoor radon samples. In this study we have used the arithmetic mean (AM) over grid cells of 10 km10 km to predict a mean indoor radon concentration at ground-floor level of buildings in the grid cells where no or few data (N &lt; 30) are available. Four interpolation techniques have been tested: inverse distance weighting (IDW), ordinary kriging (OK), collocated cokriging with uranium concentration as a secondary variable (CCK), and regression kriging with topsoil geochemistry and bedrock geology as secondary variables (RK). Cross-validation exercises have been carried out to assess the uncertainties associated with each method. Of the four methods tested, RK has proven to be the best one for predicting mean indoor radon concentrations; and by combining the RK predictions with theAMof the grids with 30 or more measurements, a Pan-European Indoor Radon Map has been produced. This map represents a first step towards a European radon exposure map and, in the future, a radon dose map

Rapid Atlantification along the Fram Strait at the beginning of the 20th century.

The recent expansion of Atlantic waters into the Arctic Ocean represents undisputable evidence of the rapid changes occurring in this region. Understanding the past variability of this “Atlantification” is thus crucial in providing a longer perspective on the modern Arctic changes. Here, we reconstruct the history of Atlantification along the eastern Fram Strait during the past 800 years using precisely dated paleoceanographic records based on organic biomarkers and benthic foraminiferal data. Our results show rapid changes in water mass properties that commenced in the early 20th century—several decades before the documented Atlantification by instrumental records. Comparison with regional records suggests a poleward expansion of subtropical waters since the end of the Little Ice Age in response to a rapid hydrographic reorganization in the North Atlantic. Understanding of this mechanism will require further investigations using climate model simulations

European Atlas of Natural Radiation

Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose. This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources. It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations. This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to: • familiarize itself with natural radioactivity; • be informed about the levels of natural radioactivity caused by different sources; • have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor; • and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.JRC.G.10-Knowledge for Nuclear Security and Safet

European Atlas of Natural Radiation

Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose.This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources. It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations.This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to: • familiarize itself with natural radioactivity;• be informed about the levels of natural radioactivity caused by different sources;• have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor;• and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.Additional information at: https://remon.jrc.ec.europa.eu/About/Atlas-of-Natural-Radiatio

Rilevamento di dettaglio della zona del Passo Val Clapa (Austroalpino superiore, Alta Val di Non)

Questo elaborato ha come obiettivo il rilevamento geologico di dettaglio di alcuni affioramenti del basamento polimetamorfico della Falda del Tonale, nella zona del Passo Val Clapa (Alta Val di Non, TN), e di verificare l’attribuzione delle litologie all’Unità d’Ultimo, di alto grado metamorfico, o a quella del Tonale, di più basso grado. In due affioramenti nelle immediate vicinanze del Passo Val Clapa sono stati rinvenuti principalmente gneiss e gneiss migmatitici a granato e cianite, anfiboliti e miloniti, mentre in un affioramento a E del passo gneiss migmatitici a granato e cianite, migmatiti (stromatiti e nebuliti) e ultramafiti. Le foliazioni, definite dall’orientazione preferenziale dei minerali, indicano due direzioni principali: un’orientazione NNE-SSW, immergente verso ESE, rilevata nelle rocce milonitiche, che è stata correlata alla presenza della linea della Val Clapa; un’orientazione NW-SE, immergente verso NE, insieme ad una blanda piega con asse orientato NNE-SSW, rilevata nelle ultramafiti e nelle loro rocce incassanti. Sono state inoltre misurate le giaciture dei principali set di fratture che interessano gli ammassi ed è stata documentata la presenza di pseudotachiliti all’interno delle miloniti. Il corpo ultramafico è stato cartografato al contatto fra stromatiti e nebuliti e quindi all’interno dell’Unità d’Ultimo. Le miloniti, invece, rimangono di attribuzione incerta, anche se il loro ritrovamento in associazione con anfiboliti retrocesse in facies scisti verdi e di pegmatiti faccia propendere per un’assegnazione all’Unità del Tonale. Un’analisi di dettaglio degli gneiss affioranti nelle vicinanze delle miloniti permetterebbe di classificarli come paragneiss a sillimanite, caratteristici dell’Unità del Tonale, o come paragneiss a granato e cianite, diagnostici dell’Unità d’Ultimo, contribuendo alla corretta attribuzione geologica di questi terreni

The first version of the Pan-European Indoor Radon Map

A hypothetical Pan-European Indoor Radon Map has been developed using summary statistics estimated from 1.2 million indoor radon samples. In this study we have used the arithmetic mean (AM) over grid cells of 10 km × 10 km to predict a mean indoor radon concentration at ground-floor level of buildings in the grid cells where no or few data (N<30) are available. Four interpolation techniques have been tested: inverse distance weighting (IDW), ordinary kriging (OK), collocated cokriging with uranium concentration as a secondary variable (CCK), and regression kriging with topsoil geochemistry and bedrock geology as secondary variables (RK). Cross-validation exercises have been carried out to assess the uncertainties associated with each method. Of the four methods tested, RK has proven to be the best one for predicting mean indoor radon concentrations; and by combining the RK predictions with the AM of the grids with 30 or more measurements, a Pan-European Indoor Radon Map has been produced. This map represents a first step towards a European radon exposure map and, in the future, a radon dose map.JRC.G.10-Knowledge for Nuclear Security and Safet

Coastal permafrost was massively eroded during the Bølling-Allerød warm period

Acknowledgements: We thank all the people working in the Marine Geochemistry group at the Alfred Wegener Institute in Bremerhaven for the help and support. The Master and crew of the R/V Helmer Hanssen are gratefully acknowledged for their help during the coring. This study was supported by Ca’ Foscari University of Venice as part of the PhD programme in Polar Sciences. T.T. acknowledges the Italian Research Program in the Arctic (PRA-2019) for financial support (PAST-HEAT project). A.N., T.T. and G.M. acknowledge the Italian-German partnership on “Chronologies for Polar Paleoclimate Archives (PAIGE)” and the funding from the Helmholtz European Partnering.The Bølling-Allerød interstadial (14,700–12,900 years before present), during the last deglaciation, was characterized by rapid warming and sea level rise. Yet, the response of the Arctic terrestrial cryosphere during this abrupt climate change remains thus far elusive. Here we present a multi-proxy analysis of a sediment record from the northern Svalbard continental margin, an area strongly influenced by sea ice export from the Arctic, to elucidate sea level - permafrost erosion connections. We show that permafrost-derived material rich in biospheric carbon became the dominant source of sediments at the onset of the Bølling-Allerød, despite the lack of direct connections with permafrost deposits. Our results suggest that the abrupt temperature and sea level rise triggered massive erosion of coastal ice-rich Yedoma permafrost, possibly from Siberian and Alaskan coasts, followed by long-range sea ice transport towards the Fram Strait and the Arctic Ocean gateway. Overall, we show how coastal permafrost is susceptible to large-scale remobilization in a scenario of rapid climate variability

Coastal permafrost was massively eroded during the Bølling-Allerød warm period

Acknowledgements: We thank all the people working in the Marine Geochemistry group at the Alfred Wegener Institute in Bremerhaven for the help and support. The Master and crew of the R/V Helmer Hanssen are gratefully acknowledged for their help during the coring. This study was supported by Ca’ Foscari University of Venice as part of the PhD programme in Polar Sciences. T.T. acknowledges the Italian Research Program in the Arctic (PRA-2019) for financial support (PAST-HEAT project). A.N., T.T. and G.M. acknowledge the Italian-German partnership on “Chronologies for Polar Paleoclimate Archives (PAIGE)” and the funding from the Helmholtz European Partnering.AbstractThe Bølling-Allerød interstadial (14,700–12,900 years before present), during the last deglaciation, was characterized by rapid warming and sea level rise. Yet, the response of the Arctic terrestrial cryosphere during this abrupt climate change remains thus far elusive. Here we present a multi-proxy analysis of a sediment record from the northern Svalbard continental margin, an area strongly influenced by sea ice export from the Arctic, to elucidate sea level - permafrost erosion connections. We show that permafrost-derived material rich in biospheric carbon became the dominant source of sediments at the onset of the Bølling-Allerød, despite the lack of direct connections with permafrost deposits. Our results suggest that the abrupt temperature and sea level rise triggered massive erosion of coastal ice-rich Yedoma permafrost, possibly from Siberian and Alaskan coasts, followed by long-range sea ice transport towards the Fram Strait and the Arctic Ocean gateway. Overall, we show how coastal permafrost is susceptible to large-scale remobilization in a scenario of rapid climate variability.</jats:p