Exploration for concealed orebodies by the analysis of volatile organic compounds contained in surface rocks: Trèves Zn-Pb deposit (Gard, France)     

J.R. Disnar  B. Gauthier 《Journal of Geochemical Exploration》1988,30(1-3)

A previous study (Disnar et al., 1986a) indicated significant volatile hydrocarbon compounds (nC₁ to C₅) in mineralized carbonate rocks of the Trèves Pb-Zn deposit (Gard Dept., France) as well as an accumulation of methane, ethylene and ethane in the hanging wall of the deposit. The present study analyzed rock samples taken from outcrops vertically above and at a distance from the deposit and identified three anomalous zones indicating the presence of concealed mineralization. The first zone is due to methane (radius about 3 km), the second, to alkenes (about 2 km) and the third, to alkanes, higher homologues of methane (about 1 km). These anomalies are interpreted as resulting from migration of these compounds through the sedimentary cover from the deposit where they could have been generated during mineralizing events, or during subsequent diagenesis. Their specific signature with regard to that given by samples taken at a distance from the orebodies can be attributed to the hydrothermal and biological processes responsible for the deposition of the ore.  相似文献   

Reply to discussion of “Magnetic studies of magma-supply and sea-floor metamorphism: Troodos ophiolite dikes” (Borradaile and Gauthier, 2005)     

G.J. Borradaile  D. Gauthier 《Tectonophysics》2007,433(1-4):149-153

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Karrat Fjord (Greenland) tsunamigenic landslide of 17 June 2017: initial 3D observations     

Dave Gauthier  Scott A. Anderson  Hermann M. Fritz  Thomas Giachetti 《Landslides》2018,15(2):327-332

On 17 June 2017, a landslide-generated tsunami reached the village of Nuugaatsiaq, Greenland, leaving four persons missing and presumed dead. Here, we present a preliminary high-resolution analysis of the tsunamigenic landslide scar based on three-dimensional (3D) reconstructions of oblique aerial photographs taken during a post-failure reconnaissance helicopter overflight. Through a 3D quantitative comparison with pre-failure topography, we estimate that approximately 58 million m³ of rock and colluvium (talus) was mobilized during the landslide, 45 million m³ of which reached the fjord, resulting in a destructive tsunami. We classify this event as a “tsunamigenic extremely rapid rock avalanche,” which likely released along a pre-existing metamorphic fabric, bounded laterally by slope-scale faults. Further analysis is required to properly characterize this landslide and adjacent unstable slopes, and to better understand the tsunami generation.  相似文献   

Cadmium accumulation by marine bacteria     

G.N. Flatau  M.J. Gauthier 《Marine environmental research》1985,17(2-4)

Complexation of metals by marine bacteria is a well known phenomenon.¹ In the marine environment it may play a determining role in the mobilisation of metals and their transfer into sediments² or through food chains.³ However, only a limited number of studies have analysed metal binding mechanisms in marine bacteria, the cell structure of which depends more closely on the ionic composition of the environment.⁴ The aim of this work was to investigate the mechanisms responsible for the accumulation of cadmium by Gram negative marine bacteria.  相似文献   

A new flow for Canadian young hydrologists: Key scientific challenges addressed by research cultural shifts     

Caroline Aubry-Wake  Lauren D. Somers  Haley Alcock  Aspen M. Anderson  Amin Azarkhish  Samuel Bansah  Nicole M. Bell  Kelly Biagi  Mariana Castaneda-Gonzalez  Olivier Champagne  Anna Chesnokova  Devin Coone  Tasha-Leigh J. Gauthier  Uttam Ghimire  Nathan Glas  Dylan M. Hrach  Oi Yin Lai  Pierrick Lamontagne-Hallé  Nicolas R. Leroux  Laura Lyon  Sohom Mandal  Bouchra R. Nasri  Nataša Popović  Tracy E. Rankin  Kabir Rasouli  Alexis Robinson  Palash Sanyal  Nadine J. Shatilla  Brandon Van Huizen  Sophie Wilkinson  Jessica Williamson  Majid Zaremehrjardy 《水文研究》2020,34(8):2001-2006

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Adaptation of the SNOWMAP algorithm for snow mapping over eastern Canada using Landsat-TM imagery     

Karem Chokmani  Kristell Dever  Monique Bernier  Yves Gauthier  Lisa-Marie Paquet 《水文科学杂志》2013,58(4):649-660

Abstract

The snow mapping algorithm SNOWMAP was adapted to Landsat-TM data and to the context of eastern Canada. Six Landsat-5 TM scenes were used. It was found that the original version of SNOWMAP greatly underestimates snow cover extent. The modification made to the original algorithm, by cancelling the minimum threshold of 0.1 on the NDVI value, allows gaps to be filled in. In addition, a spatial correction procedure applied to the modified SNOWMAP algorithm results improves snow detection under coniferous forests. Based on a limited data set of ground-based observations (only 40 sites were available), the modified SNOWMAP seems to perform better in snow detection than the original version of the algorithm. An application case is presented in order to demonstrate the relevance of the modified SNOWMAP results as a high spatial-resolution reference for the validation of historical snow maps derived from medium spatial-resolution satellite data.

Citation Chokmani, K., Dever, K., Bernier, M., Gauthier, Y. & Paquet, L.-M. (2010) Adaptation of the SNOWMAP algorithm for snow mapping over eastern Canada using Landsat-TM imagery. Hydrol. Sci. J. 55(4), 649–660.  相似文献   

Comment on “Coal-tar pavement sealant use and polycyclic aromatic hydrocarbon contamination in urban stream sediments” Physical Geography 34, 4–5, 392–415 (2013)     

Thomas D. Gauthier  Robert P. DeMott 《自然地理学》2013,34(1):84-86

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Sensitivity and evolution of sea-turtle magnetoreception: observations, modelling and constraints from geomagnetic secular variation     

Vincent Courtillotl  Gauthier Hulot  Mioara Alexandrescu  Jean-Louis le  Mouë Joseph L. Kirschvink 《地学学报》1997,9(5-6):203-207

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The Canadian Meteorological Centre's Atmospheric Transport and Dispersion Modelling Suite     

Réal D'Amours  Alain Malo  Thomas Flesch  John Wilson  Jean-Philippe Gauthier  René Servranckx 《大气与海洋》2015,53(2):176-199

This paper describes the integrated suite of Lagrangian transport and dispersion models in operation at the Canadian Meteorological Centre. These models have been in use for several years and are applied to many types of environmental emergencies covering spatial scales from the very local to the global. The Modèle Lagrangien Courte Distance (MLCD) is used for atmospheric spills of the order of a few kilometres. The Modèle Lagrangien de dispersion de particules d'ordre 1 (MLDP1) is normally used for events affecting areas less than 100?km; Modèle Lagrangien dispersion de particules d'ordre zéro (MLDP0) is used for events of continental and global consequences. The Modèle Lagrangien dispersion de particules mode mixte (MLDPmm) alternates between first-order and zeroth-order depending on criteria specified by the user. The theoretical bases of the models are presented, and the main algorithms used in their implementation are discussed. Modelling of the diffusion processes is based on a stochastic differential equation with the assumption of quasi-stationary Gaussian turbulence, locally homogeneous in the horizontal. The practical aspects of the operational implementation are also described. Using these models, results from simulations of real cases on scales ranging from the very local, to a few kilometres, to regional (approximately 100?km) to continental (approximately 1000?km) and to global (approximately 10,000?km) are compared and validated with available observational data.  相似文献   

Variability and change in the Canadian cryosphere   总被引：2，自引：1，他引：1  

C. Derksen  S. L. Smith  M. Sharp  L. Brown  S. Howell  L. Copland  D. R. Mueller  Y. Gauthier  C. G. Fletcher  A. Tivy  M. Bernier  J. Bourgeois  R. Brown  C. R. Burn  C. Duguay  P. Kushner  A. Langlois  A. G. Lewkowicz  A. Royer  A. Walker 《Climatic change》2012,115(1):59-88

During the International Polar Year (IPY), comprehensive observational research programs were undertaken to increase our understanding of the Canadian polar cryosphere response to a changing climate. Cryospheric components considered were snow, permafrost, sea ice, freshwater ice, glaciers and ice shelves. Enhancement of conventional observing systems and retrieval algorithms for satellite measurements facilitated development of a snapshot of current cryospheric conditions, providing a baseline against which future change can be assessed. Key findings include: 1. surface air temperatures across the Canadian Arctic exhibit a warming trend in all seasons over the past 40?years. A consistent pan-cryospheric response to these warming temperatures is evident through the analysis of multi-decadal datasets; 2. in recent years (including the IPY period) a higher rate of change was observed compared to previous decades including warming permafrost, reduction in snow cover extent and duration, reduction in summer sea ice extent, increased mass loss from glaciers, and thinning and break-up of the remaining Canadian ice shelves. These changes illustrate both a reduction in the spatial extent and mass of the cryosphere and an increase in the temporal persistence of melt related parameters. The observed changes in the cryosphere have important implications for human activity including the close ties of northerners to the land, access to northern regions for natural resource development, and the integrity of northern infrastructure.  相似文献