65 research outputs found

    Time-lapse capacitive resistivity imaging: a new technology concept for the monitoring of permafrost

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    The British Geological Survey, in partnership with the Universities of Sussex and Bonn, is investigating and seeking to prove a new technology concept for the non-invasive volumetric imaging and routine temporal monitoring of the thermal state of permafrost (Figure 1), a key indicator of global climate change. Capacitive Resistivity Imaging (CRI), a technique based upon a low-frequency, capacitively-coupled measurement approach (Kuras et al., 2006) is applied in order to emulate Electrical Resistivity Tomography (ERT) methodology, but without the need for galvanic contact on frozen soils or rocks. Recent work has shown that temperature-calibrated ERT using galvanic sensors (Figure 2) is capable of imaging recession and re-advance of rock permafrost in response to the ambient temperature regime. However, the use of galvanic sensors can lead to significant practical limitations on field measurements due to high levels of and large variations in contact resistances between sensors and the host material as it freezes and thaws Figure 3). The capacitive technology developed here overcomes this problem and provides a more robust means of making high-quality resistance measurements with permanently installed sensors over time. Reducing the uncertainty associated with uncontrolled noise from galvanic sensors increases the value of time-lapse ERT datasets in the context of monitoring permafrost

    Stream sediment geochemistry as a tool for enhancing geological understanding: an overview of new data from south west England

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    The requirements for quantitative data in geological surveillance are ever increasing; traditional geological maps and 3D models are evolving into quantitative conceptual models based on a broad range of analytical measurements of surface and subsurface properties. The British Geological Survey's Geochemical Baseline Survey of the Environment (G-BASE) project provides one such source of data: national coverage of stream sediment, stream water and soil geochemistry. While this geochemical data is of obvious benefit to our understanding of the present day surface environment, the rich geological diversity of south west England provides an ideal setting in which to showcase the potential of such data to enhance our understanding of the underlying bedrock. In this paper we use compositional data analysis to extract lithostratigraphic information from G-BASE stream sediment data. We find that variations in G-BASE stream sediment geochemistry correspond very closely to mapped variations in bedrock geology. Geochemical variations between the 16 lithostratigraphic domains into which we classify the region provide insight into the distinct geological histories of the lithologies within each domain, particularly in relation to depositional environments and sediment provenance

    Geological mapping using high resolution regression modelled soil geochemistry

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    Geological mapping, the classification of bedrock into distinct identifiable units, has traditionally been conducted at the discretion of the field geologist on the basis of human-observable properties such as those of mineralogical composition and texture. In recent years technological developments have allowed the collection and analysis of ever more advanced quantitative geoscientific datasets. We are now approaching a point where migration of traditional mapping procedures to the digital domain is a feasible reality, with such benefits as consistency, transferability and transparency. One issue that we encounter is that the most geologically informative measurements, such as those of chemical composition, tend to have their sampling density limited by their high cost. Meanwhile, remote sensed data will tend towards extremely high sampling density, but may lack stand-alone geological significance. Nonparametric regression techniques have the potential to negate this issue by modelling the most geologically informative measurements as complex interactions of multiple remote sensed covariates. In this poster we present the use of random forest regression to model soil geochemistry in south west England using remote sensed data, and demonstrate how clustering of the predicted high resolution soil geochemistry is able to differentiate geological units – a process that can be trained to match pre-existing rock classifications. We find that random forest regression based on remote sensed data is capable of predicting element concentrations in soils with superior accuracy to that of ordinary kriging of sparsely sampled point data. Crucially the random forest predictions incorporate the high resolution structure of the remote sensed covariates. This allows geological units, in this case defined purely on the basis of the geochemical composition of their soils, to be mapped with sharp boundaries limited only by the resolution of the remote sensed covariates. It seems likely that such techniques could take centre stage in the future of geological mapping: improving not only on the consistency of classified maps based on human observations, but also allowing the continuous mapping of any geologically constrained variables, such as radon potential, to the best resolution and accuracy that our covariate datasets can support

    The geochemical quality of soils in the Clyde basin, Scotland, UK : main controls and anthropogenic impacts [abstract only]

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    Recently, the British Geological Survey’s (BGS) Geochemical Baseline Survey of the Environment (G-BASE) project carried out extensive surveys of rural and urban soil quality in the River Clyde catchment (Clyde basin) on the west coast of Scotland. The Clyde basin is interesting as it extends from a rural upland environment in the south, to the River Clyde estuary in the north. The catchment contains an historic lead mining area known as Leadhills that was active until the mid 20th century. In addition, the estuary and lower reaches of the river formed the transport and shipping links that drove the development of Scotland’s main conurbation – the city of Glasgow, which is centred on the River Clyde. Although heavy industry and mining have now declined, the newly available G-BASE soil datasets demonstrate the impacts of urbanisation and the post-industrial legacy of the Glasgow conurbation as well as of historical mining activities on environmental quality

    Data release notes : UK Geoenergy Observatories Glasgow Geothermal Energy Research Field Site (GGERFS) ground gas, 2018 and 2019 surveys

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    In 2014, the British Geological Survey (BGS) and the Natural Environment Research Council (NERC) were tasked with developing new centres for research into the sub-surface environment to aid the responsible development of new low-carbon energy technologies in the United Kingdom (UK) and internationally. Under the United Kingdom Geoenergy Observatories (UKGEOS) project, two sites were chosen, including the Glasgow Geothermal Energy Research Field Site (GGERFS) in the Cuningar Loop-Dalmarnock area in the east of Glasgow (Figure 1). The aims of the GGERFS facility include de-risking technical aspects of mine water geothermal to assess the feasibility of extracting/storing heat energy in an urbanised former coal mine setting (Monaghan 2019; Monaghan et al. 2017; Monaghan et al. 2018). The initial phase of the GGERFS project entails installing a network of boreholes into the superficial deposits and bedrock in the Cuningar Loop-Dalmarnock area of Glasgow to characterise the geological and hydrogeological setting and assess the potential for shallow geothermal energy. The borehole network is also designed for baseline monitoring to assess the environmental status before and during the lifetime of the project. A ground gas baseline is considered important at the GGERFS site to enable us to determine if there are significant ongoing ground gas contributions from sources such as (i) leakage from mine workings/features related to legacy mine workings (ii) gas generated from components of the made ground (building rubble, mine water, other waste) and (iii) natural soil processes. The made ground at Cuningar Loop is known to have been formed from a range of prior land uses (see Ramboll 2018 a, b) and is commonly around 10 m thick. Ground gas measurement is an important tool for monitoring geoenergy sites since sensitive measurements of, for example, CO2, CH4 and associated gases can be made directly within the biosphere in which we live. Monitoring of ground gas in the vadose zone has been undertaken as part of a broader GGERFS environmental monitoring effort that includes groundwater, soil and surface water chemistry, ground movement and seismicity. The intention of ground gas monitoring, indeed the environmental monitoring effort as a whole, is to characterise pre-existing i.e. pre-operational or baseline conditions, particularly with respect to former coal mining, building demolition, waste disposal/landfill, or other industrial activities, before significant development occurs in relation to GGERFS. As such, it should be noted that the August 2018 survey precedes any development of GGERFS and can be considered ‘baseline’ in the conventional sense, whereas the May and October 2019 surveys were conducted alongside site construction but ahead of site operation. Approaches to monitoring ground gas may include long term continuous monitoring using permanently deployed instruments, and discrete surveys involving mobile, wide area screening techniques (for example open path laser, cavity ring down laser) to augment high density grids of detailed point measurements. Point measurement data from ground gas surveys conducted at the Glasgow Geothermal Energy Research Field Site (GGERFS) in August 2018, and May and October 2019 are reported. Ground gas is defined here as: a. gas concentrations in the shallow (c.70-100 cm below ground level) unsaturated zone of the subsurface, and b. gas flux at the soil-atmosphere interfac

    Geochemistry and related studies of Clyde Estuary sediments

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    Geochemical and related studies have been made of near-surface sediments from the River Clyde estuary and adjoining areas, extending from Glasgow to the N, and W as far as the Holy Loch on the W coast of Scotland, UK. Multibeam echosounder, sidescan sonar and shallow seismic data, taken with core information, indicate that a shallow layer of modern sediment, often less than a metre thick, rests on earlier glacial and post-glacial sediments. The offshore Quaternary history can be aligned with onshore sequences, with the recognition of buried drumlins, settlement of muds from quieter water, probably behind an ice dam, and later tidal delta deposits. The geochemistry of contaminants within the cores also indicates shallow contaminated sediments, often resting on pristine pre-industrial deposits at depths less than 1 m. The distribution of different contaminants with depth in the sediment, such as Pb (and Pb isotopes), organics and radionuclides, allow chronologies of contamination from different sources to be suggested. Dating was also attempted using microfossils, radiocarbon and 210Pb, but with limited success. Some of the spatial distribution of contaminants in the surface sediments can be related to grain-size variations. Contaminants are highest, both in absolute terms and in enrichment relative to the natural background, in the urban and inner estuary and in the Holy Loch, reflecting the concentration of industrial activity

    Base-Pair Resolution DNA Methylation Sequencing Reveals Profoundly Divergent Epigenetic Landscapes in Acute Myeloid Leukemia

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    We have developed an enhanced form of reduced representation bisulfite sequencing with extended genomic coverage, which resulted in greater capture of DNA methylation information of regions lying outside of traditional CpG islands. Applying this method to primary human bone marrow specimens from patients with Acute Myelogeneous Leukemia (AML), we demonstrated that genetically distinct AML subtypes display diametrically opposed DNA methylation patterns. As compared to normal controls, we observed widespread hypermethylation in IDH mutant AMLs, preferentially targeting promoter regions and CpG islands neighboring the transcription start sites of genes. In contrast, AMLs harboring translocations affecting the MLL gene displayed extensive loss of methylation of an almost mutually exclusive set of CpGs, which instead affected introns and distal intergenic CpG islands and shores. When analyzed in conjunction with gene expression profiles, it became apparent that these specific patterns of DNA methylation result in differing roles in gene expression regulation. However, despite this subtype-specific DNA methylation patterning, a much smaller set of CpG sites are consistently affected in both AML subtypes. Most CpG sites in this common core of aberrantly methylated CpGs were hypermethylated in both AML subtypes. Therefore, aberrant DNA methylation patterns in AML do not occur in a stereotypical manner but rather are highly specific and associated with specific driving genetic lesions

    European Atlas of Natural Radiation

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    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

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    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
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