Accumulation of Copper and Zinc in Danish Agricultural Soils in Intensive Pig Production Areas     

Ilse Gräber  Jørgen F. Hansen  Svend E. Olesen  Jens Petersen  Hans S. Østergaard  Lars Krogh 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):15-22

Geografisk Tidsskrift, Danish Journal of Geography 105(2):15–22, 2005

The change of Cu and Zn concentrations in Danish agricultural soils was studied in areas with intensive pig production. Cu and Zn are found in pig manure as the metals are added to pig feed as growth promoters. The changes in concentrations of total and 0.02 MEDTA extractable Cu and Zn in soils from 1986 to 1998 were determined from samples taken at two depths (0–25 cm and 25–50 cm) from 73 sites. Pig manure and mineral fertilizer was added to 60 sites whereas fertilizer only was used on 13 sites. During the survey period soil Cu concentrations increased in both depths but mostly in the sites where pig manure was added. Furthermore, the results indicated that some plant-available Cu and Zn were transported from the topsoil to the subsoil. No significant change in soil Zn concentration was found although a slight reduction was observed. Comparing soil metal concentrations observed in 1998 to the total pig manure application in a 12-year period, it was observed that application of manure caused an accumulation of Cu and of Zn in the upper 50 cm soil. The accumulation rates correspond to the Cu and Zn concentrations in the pig manure.  相似文献   

Precise 14C ages of the Vedde and Saksunarvatn ashes and the Younger Dryas boundaries from western Norway and their comparison with the Greenland Ice Core (GICC05) chronology     

ØYSTEIN S. LOHNE  JAN MANGERUD  HILARY H. BIRKS 《第四纪科学杂志》2013,28(5):490-500

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Deeply rooted glaciotectonism in western Denmark: geological composition,structural characteristics and the origin of Varde hill‐island     

A.‐S. HØYER  F. JØRGENSEN  J. A. PIOTROWSKI  P. R. JAKOBSEN 《第四纪科学杂志》2013,28(7):683-696

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BIBLIOGRAPHIES     

S. E. JØRGENSEN 《水文科学杂志》2013,58(2):143-149

Abstract

On a regional scale (from about 10 to 10⁵km²) estimations of actual evapotranspiration ET for water balance equations are generally missing. The various methods available at present are briefly described and discussed. The use of remote sensing, in particular infra-red thermometry by satellite, in conjunction with soil energy budget data, is the only method to provide satisfactory data on the same scale in space and lime for water balance models. This method is being studied at the INRA Bioclimatology Station at Avignon in the framework of the European ‘Tellus’ project for using HCMM satellite data. Systems for continuously recording the components of the energy budget and ET have been installed in the Crau plain, north of Marseilles, in both a dry area and a large area of irrigated pastures. By combining the recorded measurements with the satellite data and starting from values for elements of 25 ha (500 m × 500 m), the ET for the whole of the Crau plain can be estimated. First results are analysed and the possibilities and limitations of the method are discussed.  相似文献   

Timing of the younger dryas glacial maximum in western Norway     

Øystein S. Lohne  Jan Mangerud  John Inge Svendsen 《第四纪科学杂志》2012,27(1):81-88

This study precisely constrains the timing of the Younger Dryas (YD) glacial maximum in south‐western Norway by utilizing sediment records from lake basins. Two of the basins, located on the distal side of the mapped Herdla–Halsnøy Moraine, received meltwater directly from the ice sheet only when the ice margin reached its maximum extent during the YD. In the cores, the ice maximum is represented by well‐defined units with meltwater deposits, dominantly laminated silt. Plant macrofossils in the sediment sequences are common and we obtained 18 radiocarbon ages from one of the cores. By applying Bayesian age–depth modelling we obtained a precise date for this meltwater event and thereby also for the timing of the YD glacial maximum. We conclude that the ice‐sheet advance culminated at the Halsnøy Moraine at 11 760 ± 120 cal a BP, and that the ice margin stayed in this position for 170 ± 120 years. The subsequent retreat started at 11 590 ± 100 cal a BP, i.e. close to the YD/Holocene boundary. Withdrawal was probably triggered by abrupt climatic warming at this time. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Late-Quaternary biogeographic scenarios for the brown bear (Ursus arctos), a wild mammal model species     

John Davison  Simon Y.W. Ho  Sarah C. Bray  Marju Korsten  Egle Tammeleht  Maris Hindrikson  Kjartan Østbye  Eivind Østbye  Stein-Erik Lauritzen  Jeremy Austin  Alan Cooper  Urmas Saarma 《Quaternary Science Reviews》2011,30(3-4):418-430

This review provides an up-to-date synthesis of the matrilineal phylogeography of a uniquely well-studied Holarctic mammal, the brown bear. We extend current knowledge by presenting a DNA sequence derived from one of the earliest known fossils of a polar bear (dated to 115 000 years before present), a species that shares a paraphyletic mitochondrial association with brown bears. A molecular clock analysis of 140 mitochondrial DNA sequences, including our new polar bear sequence, provides novel insights into the times of origin for different brown bear clades. We propose a number of regional biogeographic scenarios based on genetic data, divergence time estimates and paleontological records. The case of the brown bear provides an example for researchers working with less well-studied taxa: it shows clearly that phylogeographic models based on patterns of modern genetic variation alone can be substantially improved by including data on historical patterns of genetic diversity in the form of ancient DNA sequences derived from accurately dated samples and by using an approach to divergence-time estimation that suits the data under analysis. Using such approaches it has been possible to (i) establish that the processes shaping modern genetic diversity in brown bears acted recently, within the last three glacial cycles; (ii) distinguish among hypotheses concerning species’ responses to climatic oscillations in accordance with the lack of phylogeographic structure that existed in brown bears prior to the last glacial maximum (LGM); (iii) reassess theories linking monophyletic brown bear populations to particular LGM refuge areas; and (iv) identify vicariance events and track analogous patterns of migration by brown bears out of Eurasia to North America and Japan.  相似文献   

Synthetic pulsational line profile variations     

R. Oreiro  J. H. Telting  R. H. Østensen  M. Briquet  C. Aerts  U. Heber  M. Vučković 《Astrophysics and Space Science》2010,329(1-2):211-216

We have produced simulated time series of high resolution spectroscopy for sdBs. We present the first results of testing classical mode identification techniques. Here, in particular, we analyse the behaviour of individual spectral lines and discuss the results and applicability of the moment method.  相似文献   

The HYPER-MUCHFUSS project—target selection and analysis     

A. Tillich  S. Geier  U. Heber  H. Hirsch  P. F. L. Maxted  T. Marsh  B. Gänsicke  R. Napiwotzki  R. Østensen  R.-D. Scholz 《Astrophysics and Space Science》2010,329(1-2):63-68

The HYPER-MUCHFUSS project targets a population of high velocity subluminous B stars to discover either close binaries with massive unseen companions or hyper-velocity stars. Our starting point is the enormous database of SDSS. We preselected sdO/B candidates by colour and classified them by visual inspection of their spectra. We measured the radial velocity from the coadded SDSS spectra, which serves as first epoch measurement. Stars with high Galactic rest-frame velocities were selected and second epoch observations were obtained starting in 2007 at several sites. For the brighter targets we also included the SDSS individual spectra as additional information. In the course of our survey we observed 88 out of 265 stars from our target list. We discovered 39 HVS candidates as well as 49 close binaries. In addition we analysed all single spectra of sdBs from SDSS and found 120 close binaries. For the targets with constant RVs we performed a proper motion analysis with the highest possible accuracy from the available digitised photographic plates. Together with the analysed spectra and the calculation of the spectroscopic distance, we calculated complete trajectories and deduced the origins of these stars. Targets with high RV variability on short timescales were selected for follow-up. Numerical simulations based on the period and companion mass distribution of the known sdB binary sample were carried out to optimise the target selection and single out candidate binaries with massive companions. The follow-up campaign using WHT/ISIS and CAHA-3.5m/TWIN started in 2009.  相似文献   

Towards a calculation of organic carbon release from erosion of Arctic coasts using non-fractal coastline datasets     

H. Lantuit  V. Rachold  W.H. Pollard  F. Steenhuisen  R. Ødegård  H.-W. Hubberten 《Marine Geology》2009,257(1-4):1-10

Changing environmental conditions in the Arctic will affect patterns of coastal erosion processes and thus modify the carbon cycle in the Arctic Ocean. To address this issue, a coastal classification of the Arctic was established to provide the first reliable estimate of organic carbon input from coastal erosion to the Arctic Ocean. The calculation relies on geomorphic parameters and the length of the coastline in the form of a line dataset used in geographical information systems (the World Vector Shoreline). The statistical self-similarity of Arctic shorelines (i.e. the fact that they exhibit similar features and hence different lengths at different scales) hampers the calculation process. Delineating the same section of shoreline at different spatial scales produces changes in the calculated length of the coastline and therefore in the volume of sediment released by up to 30% in some cases. The amount of change differs depending on the type and morphology of the coastline. The length of the World Vector Shoreline does not correlate well to any one scale and is inappropriate for use at the global level. Computations of erosion based on areas instead of lengths (i.e. buffers instead of shoreline lengths) provide a valuable yet simple substitute to the length-based method. Differences in quantities of eroded sediment are, on average, 70% less affected by scale changes when areas are used. Area-based methods are therefore recommended for circum-polar, computation-demanding, shoreline-based erosion calculations.  相似文献   

Analysis of shallow gas and fluid migration within the Plio-Pleistocene sedimentary succession of the SW Barents Sea continental margin using 3D seismic data     

Karin Andreassen  Espen Glad Nilssen  Christian M. Ødegaard 《Geo-Marine Letters》2007,27(2-4):155-171

Three-dimensional (3D) seismic data acquired for hydrocarbon exploration reveal that gas accumulations are common within the 2–3 km thick Plio-Pleistocene stratigraphic column of the south-western Barents Sea continental margin. The 3D seismic data have relatively low-frequency content (<40 Hz) but, due to dense spatial sampling, long source-receiver offsets, 3D migration and advanced interpretation techniques, they provide surprisingly detailed images of inferred gas accumulations and the sedimentary environments in which they occur. The presence of gas is inferred from seismic reflection segments with anomalously high amplitude and reversed phase, compared with the seafloor reflection, so-called bright spots. Fluid migration is inferred from vertical zones of acoustic masking and acoustic pipes. The 3D seismic volume allows a spatial analysis of amplitude anomalies inferred to reflect the presence of gas and fluids. At several locations, seismic attribute maps reveal detailed images of flat spots, inferred to represent gas–water interfaces. The data indicate a focused fluid migration system, where sub-vertical faults and zones of highly fractured sediments are conduits for the migration of gas-bearing fluids in Plio-Pleistocene sediments. Gas is interpreted to appear in high-porosity fan-shaped sediment lobes, channel and delta deposits, glacigenic debris flows and sediment blocks, probably sealed by low-permeability, clayey till and/or (glacio)marine sediments. Gas and fluid flow are here attributed mainly to rapid Plio-Pleistocene sedimentation that loaded large amounts of sedimentary material over lower-density, fine-grained Eocene oozes. This probably caused pore-fluid dewatering of the high-fluid content oozes through a network of polygonal faults. The study area is suggested to have experienced cycles of fluid expulsion and hydrocarbon migration associated with glacial–interglacial cycles.  相似文献