Stream water geochemistry from selected catchments on the Kola Peninsula (NW Russia)and in neighbouring areas of Finland and Norway: 1. Elements levels and sources     

Patrice de Caritat  Clemens Reimann  Matti Äyräs  Heikki Niskavaara  Viktor A. Chekushin  Vladimir A. Pavlov 《Aquatic Geochemistry》1996,2(2):149-168

The pH, electrical conductance and concentration of six anions and 33 cations were determined in stream waters sampled in 1994 from eight arctic catchments on and adjacent to the Kola Peninsula (Russia, Finland and Norway). The catchments are located at various distances (5–300 km) from the major industrial emissions centres of Monchegorsk, Nikel and Zapoljarniy in Russia. The source of the elements can be (1) natural, marine (sea spray), (2) natural, geogenic (blowing soil/dust, till, bedrock), and/or (3) anthropogenic, industrial (emissions from smelters, dust from mining, etc.), each source showing a distinct signature. The median concentration of many contaminants can vary by up to three orders of magnitude from polluted to remote locations, and the concentration ranges observed in different catchments often do not overlap. This implies that contamination falls sharply with distance from source, but is quite profound and lasting close to the emission centres. Elevated trace metal contents in the most polluted streams indicates that deposited contaminants are transferred to the aquatic ecosystem, and eventually can reach the ocean.  相似文献   

Stream water geochemistry from selected catchments on the Kola Peninsula (NW Russia) and in neighbouring areas of Finland and Norway: 2. Time-series     

Patrice de Caritat  Clemens Reimann  Matti Äyräs  Heikki Niskavaara  Viktor A. Chekushin  Vladimir A. Pavlov 《Aquatic Geochemistry》1996,2(2):169-184

Stream water composition, measured weekly for 8–9 months in 1994 in three arctic catchments on and around the Kola Peninsula (Russia, Finland and Norway), is presented in the form of time-series. In all three catchments, snowmelt causes a major dilution of the stream water, as reflected by marked dips in electrical conductance. In the most polluted catchment (C2), the snowmelt flood (the major hydrological event at these latitudes) is reflected in the stream water by a pH dip and a pulse in technogenic heavy metals (Cu, Ni, etc.), Al and S. This results from melting of the snow laden with heavy metals and sulphate, and from leaching of the topsoil layer. In the most pristine catchment (C8), snowmelt causes no heavy metal pulse (remote location) but yields an increase in stream water Al (acidic lithology/overburden). In the intermediate catchment (C5), very subdued heavy metal and S increases are noticeable in the stream water, whilst its pH increases steadily until summer (basic lithology). Some elements (Cl, S) may be mobilised out of the snowpack before its complete thawing and reach the stream 1–2 weeks ahead of the heavy metals. The substrate (soil, overburden and bedrock) of a catchment controls to a large extent its ability to buffer acid inputs.  相似文献   

Aerial photosieving of exposed gravel bars for the rapid calibration of airborne grain size maps     

Stephen J. Dugdale  Patrice E. Carbonneau  David Campbell 《地球表面变化过程与地形》2010,35(6):627-639

In recent years, fluvial remote sensing has seen considerable progress in terms of methods capable of system scale characterisation of river catchments. One key development is automated grain size mapping. It has been shown that high resolution aerial photography can be used to automatically produce grain size maps over entire rivers. However, current aerial grain size mapping procedures all require field calibration data. The collection of such data can be costly and problematic in the case of remote areas. This paper presents a method developed to remove the need for field based calibration data. Called ‘aerial photosieving’, this method consists of using the same very high resolution aerial imagery intended for grain size map production to visually measure particle sizes on‐screen in order to provide calibration data. The paper presents a rigorous comparison of field‐based photosieving calibration data and aerial photosieving calibration data. Statistical tests are used to demonstrate that aerial photosieving gives similar results when compared with field‐based data with only a slight systematic overprediction. The new aerial photosieving method therefore simplifies the overall procedure required for the production of grain size maps and thus improves the cost‐effectiveness and potential availability of this new fluvial remote sensing technology. Copyright © 2010 John Wiley &Sons, Ltd.  相似文献   

Interactive effects of metal contamination and pathogenic organisms on the marine bivalve Cerastoderma edule     

Ika Paul-Pont  Patrice Gonzalez  Florence Jude  Line Bourrasseau  Frances Haynes  Christine Paillard 《Marine pollution bulletin》2010,60(4):515-118

The present study evaluated the interactive effects of cadmium contamination and pathogenic organisms (trematodes Himasthla elongata and bacteria Vibrio tapetis) singularly and in combination during 7 days on the bivalve Cerastoderma edule. Some defense-related activities were analyzed such as genetic expression, metallothionein and immune responses. Trematode metacercarial infection, similar whatever the treatment, induced the strongest responses of immune parameters. Particularly, the interaction between cadmium and parasite exposures induced unusual responses on gene expression and immune responses. No effect of bacterial challenge appeared on bivalve responses, nevertheless a strong mortality of V. tapetis infected cockles occured between 7 and 14 days. Cadmium bioaccumulation was significantly modulated by both pathogenic organisms. Furthermore, an antagonistic effect of trematodes and bacteria was shown on metal bioaccumulation of co-infected cockles. These results highlighted the importance of considering the multiplicity of perturbation sources in coastal ecosystems to assess the health status of organisms.  相似文献   

Cost‐effective non‐metric photogrammetry from consumer‐grade sUAS: implications for direct georeferencing of structure from motion photogrammetry          下载免费PDF全文

Patrice E. Carbonneau  James T. Dietrich 《地球表面变化过程与地形》2017,42(3):473-486

The declining costs of small Unmanned Aerial Systems (sUAS), in combination with Structure‐from‐Motion (SfM) photogrammetry have triggered renewed interest in image‐based topography reconstruction. However, the potential uptake of sUAS‐based topography is limited by the need for ground control acquired with expensive survey equipment. Direct georeferencing (DG) is a workflow that obviates ground control and uses only the camera positions to georeference the SfM results. However, the absence of ground control poses significant challenges in terms of the data quality of the final geospatial outputs. Notably, it is generally accepted that ground control is required to georeference, refine the camera calibration parameters, and remove any artefacts of optical distortion from the topographic model. Here, we present an examination of DG carried out with low‐cost consumer‐grade sUAS. We begin with a study of surface deformations resulting from systematic perturbations of the radial lens distortion parameters. We then test a number of flight patterns and develop a novel error quantification method to assess the outcomes. Our perturbation analysis shows that there exists families of predictable equifinal solutions of K₁‐K₂ which minimize doming in the output model. The equifinal solutions can be expressed as K₂ = f (K₁) and they have been observed for both the DJI Inspire 1 and Phantom 3 sUAS platforms. This equifinality relationship can be used as an external reliability check of the self‐calibration and allow a DG workflow to produce topography exempt of non‐affine deformations and with random errors of 0.1% of the flying height, linear offsets below 10 m and off‐vertical tilts below 1°. Whilst not yet of survey‐grade quality, these results demonstrate that low‐cost sUAS are capable of producing reliable topography products without recourse to expensive survey equipment and we argue that direct georeferencing and low‐cost sUAS could transform survey practices in both academic and commercial disciplines. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

UVolution: Compared photochemistry of prebiotic organic compounds in low Earth orbit and in the laboratory     

Yuan Yong Guan  Patrice Coll  Didier Chaput  Hervé Cottin 《Planetary and Space Science》2010,58(10):1327-1996

Solar UV radiation is a major source of energy for chemical evolution of organic materials in the Solar System. Therefore studies on the photostability of organic compounds in extraterrestrial environments are of prime importance for the understanding of the extraterrestrial origin of organic materials on Earth. A series of organic samples have been photolysed in Earth orbit during the ESA BIOPAN 6 mission (14-26/09/2007). Their photochemical lifetime has been measured and compared to results recorded in the laboratory using a lamp that simulates the solar radiation in the VUV domain. The half-lives at a distance of 1 AU from the Sun have been measured for glycine, xanthine, hypoxanthine, adenine, guanine, urea, carbon suboxide polymer ((C₃O₂)_n) and HCN polymer. They range from a few days to a lower limit of a few tens of days for the most photoresistant (e.g. adenine, guanine, hypoxanthine). Lifetimes measured in terrestrial orbit are very different from those derived with laboratory experiments. These measurements confirm that it is difficult to simulate the solar spectrum below 200 nm in the laboratory. Results are discussed and highlight the necessity to conduct experiments in orbit, and for longer duration. It also appears that the laboratory measurements made in VUV must be extrapolated very cautiously to the different environments they are supposed to simulate.  相似文献   

Provenance record of late Maastrichtian–late Palaeocene Andean Mountain building in the Amazonian retroarc foreland basin (Madre de Dios basin,Peru)          下载免费PDF全文

Mélanie Louterbach  Martin Roddaz  Pierre‐Olivier Antoine  Laurent Marivaux  Sylvain Adnet  Julien Bailleul  Elton Dantas  Roberto Ventura Santos  Farid Chemale Jr  Patrice Baby  Caroline Sanchez  Ysabel Calderon 《地学学报》2018,30(1):17-23

Biostratigraphic, sedimentological and provenance analyses suggest that a proto‐Andean Cordillera already existed in southern Peru by late Maastrichtian–late Palaeocene times. A 270‐m‐thick stratigraphic section shows changes in depositional environments from shallow marine (early Maastrichtian) to non‐marine (late Maastrichtian) then back to estuarine (late Palaeocene) conditions. An erosional surface separates lower Maastrichtian from upper Maastrichtian deposits. Above this surface, the late Maastrichtian unit exhibits moderately developed palaeosols and syn‐sedimentary normal faults. The sedimentary evolution is accompanied by a decrease in sedimentation rate and by changes in provenance. Shallow marine lower Maastrichtian deposits have a cratonic provenance as shown by their low εNd(0) values (?15 to ?16) and the presence of Precambrian inherited zircon grains. The upper Maastrichtian deposits have a mixed Andean and cratonic origin with εNd(0) values of ~12.6 and yield the first Cretaceous and Permo‐Triassic zircon grains. Estuarine to shallow marine upper Palaeocene deposits have an Andean dominant source as attested by higher εNd(0) values (?6 to ?10) and by the presence of Palaeozoic and Late Cretaceous zircon grains. The changes in depositional environments and sedimentation rates, as well as the shift in detrital provenance, are consistent with a late Maastrichtian–late Palaeocene period of Andean mountain building. In agreement with recently published studies, our data suggest that an Andean retroarc foreland basin was active by late Maastrichtian–late Palaeocene times.  相似文献   

Erratum: New constraints on the thickness of the Semail ophiolite in the Northern Emirates     

Charles Naville  Martine Ancel  Paul Andriessen  Patrice Ricarte  François Roure 《Arabian Journal of Geosciences》2011,4(3-4):687-687

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A Compilation of Silicon and Thirty One Trace Elements Measured in the Natural River Water Reference Material SLRS-4 (NRC-CNRC)   总被引：1，自引：0，他引：1  

Delphine Yeghicheyan  Jean Carignan  Michel Valladon  Martine Bouhnik Le  Coz  Florence Le Cornec  Maryse Castrec-Rouelle  Michel Robert  Luc Aquilina  Emmanuel Aubry  Carine Churlaud  Aline Dia  Samuel Deberdt  Bernard Dupré  Rémi Freydier  Gérard Gruau  Odile Hénin  Anne-Marie de  Kersabiec  Joël Macé  Luc Marin  Nicole Morin  Patrice Petitjean  Elodie Serrat 《Geostandards and Geoanalytical Research》2001,25(2-3):465-474

The natural river water certified reference material SLRS-4 (NRC-CNRC, National Research Council-Conseil National de Recherches Canada) has been routinely analysed for major and trace elements by six French laboratories. Most measurements were made using inductively coupled plasma-mass spectrometry. For silicon and thirty one trace elements (rare earth elements, Ag, B, Br, Cs, Ga, Ge, Li, P, Pd, Rb, Se, Th, Ti, Tl, W, Y and Zr), no certified values are assigned by NRC-CNRC. We propose some compilation values and related uncertainties according to the results obtained by the different laboratories.  相似文献   

Erratum to: Towards a More Equitable Use of Mineral Resources     

Patrice Christmann 《Natural Resources Research》2018,27(2):179-180

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