A Dasymetric Map of Maine Lobster Trap Distribution Using Local Knowledge     

Christopher E. Brehme  Patrice McCarron  Heather Tetreault 《The Professional geographer》2013,65(1):98-109

As coastlines face increased development pressure, it is important to have the best available spatial information on coastal activities, including commercial fishing. This article describes the creation of a fine-scale spatial representation of lobster fishing activity along the Maine coast of the United States using a combination of participatory geographic information systems (GIS) and dasymetric mapping methods. These methods are employed here to support data collection from a large number of active lobster harvesters while maintaining individual privacy. The resulting representation of the fishery is designed as a planning tool for identifying potential interactions between marine resources and human activities.  相似文献   

Fluid escape features as relevant players in the enhancement of seafloor stability?     

Vincent Riboulot  Patrice Imbert  Antonio Cattaneo  Michel Voisset 《地学学报》2019,31(6):540-548

Fluid migration within the sedimentary column contributes significantly to slope failure and pockmark formation and can be an effective triggering mechanism to generate submarine landslides. Pockmarks are thus commonly listed among geohazards. Contrary to these accepted notions, we propose here an alternative view of pockmarks with an example from the Eastern Niger Submarine Delta: Pockmarks and associated chimneys may increase or modify the shear strength of sedimentary layers and locally enhance seafloor stability. The analysis of two 3D seismic volumes shows that a landslide deposit divides into two branches around a cluster of three pockmark chimneys, interpreted to impede its further development. The morphological characteristics of a slide constrained by fluid seepage features show the potential role of fluid escape in marine sediment strengthening.  相似文献   

Global warming of the mantle beneath continents back to the Archaean     

Nicolas Coltice  Hervé Bertrand  Patrice Rey  Fred Jourdan  Benjamin R. Phillips  Yanick Ricard 《Gondwana Research》2009,15(3-4):254-266

Throughout its history, the Earth has experienced global magmatic events that correlate with the formation of supercontinents. This suggests that the distribution of continents at the Earth's surface is fundamental in regulating mantle temperature. Nevertheless, most large igneous provinces (LIPs) are explained in terms of the interaction of a hot plume with the lithosphere, even though some do not show evidence for such a mechanism. The aggregation of continents impacts on the temperature and flow of the underlying mantle through thermal insulation and enlargement of the convection wavelength. Both processes tend to increase the temperature below the continental lithosphere, eventually triggering melting events without the involvement of hot plumes. This model, called mantle global warming, has been tested using 3D numerical simulations of mantle convection [Coltice, N., Phillips, B.R., Bertrand, H., Ricard, Y., Rey, P. (2007) Global warming of the mantle at the origin of flood basalts over supercontinents. Geology 35, 391–394.]. Here, we apply this model to several continental flood basalts (CFBs) ranging in age from the Mesozoic to the Archaean. Our numerical simulations show that the mantle global warming model could account for the peculiarities of magmatic provinces that developed during the formation of Pangea and Rodinia, as well as putative Archaean supercontinents such as Kenorland and Zimvaalbara.  相似文献   

Stratigraphic responses to a major tectonic event in a foreland basin: the Ecuadorian Oriente Basin from Eocene to Oligocene times   总被引：2，自引：0，他引：2  

Frdric Christophoul  Patrice Baby  Celso Dvila 《Tectonophysics》2002,345(1-4)

The Eocene to Oligocene sediments of the Ecuadorian Oriente Basin record two kinds of second-order stratigraphic response to the tectonic evolution. Lower Eocene shows evidences of local scale syntectonic deposits. This tectonic activity can be related to right lateral convergent movements inverting pre-cretaceous extensional structures. Upper Eocene and Oligocene sediments are integrated as the expression of an isostatic rebound characterizing a basin scale syntectonic deposition. This response is evidenced by a reciprocal architecture of the depositional sequences identified in the sedimentary formations. These data have allowed us to propose a new geodynamic model for the Paleogene evolution of the Oriente Basin.  相似文献   

The threshold effect of image resolution on image‐based automated grain size mapping in fluvial environments     

Patrice E. Carbonneau 《地球表面变化过程与地形》2005,30(13):1687-1693

It has recently been demonstrated that surficial grain sizes in fluvial environments could be derived with automated methods applied to airborne digital imagery having a ground resolution of 3 cm. This letter seeks to further examine the potential of digital imagery for automated grain size mapping. In order to broaden the application of automated grain size mapping from airborne imagery, the effect of image resolution needs further study. Automated grain size mapping was attempted on an airborne digital image with a ground resolution of 10 cm. The results show that meaningful grain size information can be derived from 10 cm imagery. However, the ground resolution of the image acts as a size threshold below which no grain size information is detectable. Therefore, these results strongly suggest that future applications of automated grain size mapping will always be dependent on the ground resolution made available by the technology in use at the time of image acquisition. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Intensifying groundwater acidification at Birkenes, southern Norway     

Patrice de Caritat 《Journal of Hydrology》1995,170(1-4):47-62

Groundwater chemical data from Birkenes, southern Norway, collected during the period October 1980 to November 1993, reveal intensifying acidification in the 1990s, as evidenced by decreases in pH, acid-neutralising capacity and alkalinity, and increases in hardness/alkalinity ratio, ‘acidification’, nitrate, non-marine sulphate (SO₄^*), non-marine hardness (Ca^* + Mg^*) and dissolved aluminium. The whole monitoring period is characterised by slopes of four or more on a plot of (Ca^* + Mg^*) vs. alkalinity.

Owing to its proximity to the sea, the Birkenes catchment receives seasalt-influenced precipitation, which results in episodic, natural acidification of the groundwater via cation exchange of marine Na⁺ with soil-bound H⁺ and/or Al³⁺. However, it is uncertain whether all of the recent groundwater acidification can be attributed to intensifying seasalt deposition alone: the steep slopes on the (Ca^* + Mg^*) vs. alkalinity plot and the increase in groundwater SO₄^* suggest that strong acids, of possible anthropogenic origin, may be involved. Additionally, seasalt deposition appears not to have increased during the 1990s: Cl⁻ content in precipitation has not increased significantly and river water pH has not decreased significantly over the period 1990–1993. The suggestion is made that the observed intensification in groundwater acidification at Birkenes partly results from the exhaustion or weakening of an acid buffering system caused by soil acidification, under persisting, even if abating, anthropogenic acid loading.  相似文献   

Composition and origin of fluids associated with lode gold deposits in a Mesoarchean greenstone belt (Warrawoona Syncline, Pilbara Craton, Western Australia) using synchrotron radiation X-ray fluorescence     

Nicolas Thébaud  Pascal Philippot  Patrice Rey  Jean Cauzid 《Contributions to Mineralogy and Petrology》2006,152(4):485-503

Microthermometry and Raman spectroscopy techniques are routinely use to constrain ore-fluids δ¹⁸O and molar proportions of anhydrous gas species (CO₂, CH₄, N₂). However, these methods remain imprecise concerning the ore-fluids composition and source. Synchrotron radiation X-ray fluorescence allows access to major and trace element concentrations (Cl, Br and K, Ca, Fe, Cu, Zn, As, Rb, Sr) of single fluid inclusion. In this paper, we present the results of the combination of these routine and newly developed techniques in order to document the fluids composition and source associated with a Mesoarchaean lode gold deposit (Warrawoona Syncline, Western Australia). Fluid inclusion analyses show that quartz veins preserved records of three fluid inclusion populations. Early fluids inclusions, related to quartz veins precipitation, are characterized by a moderate to high Br/Cl ratio relative to modern seawater, CO₂ ± CH₄ ± N₂, low to moderate salinities and significant base metal (Fe, Cu, Zn) and metalloid (As) concentrations. Late fluid inclusions trapped in secondary aqueous fluid inclusions are divided into two populations with distinct compositions. The first population consists of moderately saline aqueous brines, with a Br/Cl ratio close to modern seawater and a low concentration of base metals and metalloids. The second population is a fluid of low to moderate salinity, with a low Br/Cl ratio relative to modern seawater and significant enrichment in Fe, Zn, Sr and Rb. These three fluid inclusion populations point to three contrasting sources: (1) a carbonic fluid of mixed metamorphic and magmatic origin associated with the gold-bearing quartz precipitation; (2) a secondary aqueous fluid with seawater affinity; and (3) a surface-derived secondary aqueous fluid modified through interaction with felsic lithologies, before being flushed into the syncline. Primary carbonic fluids present similar characteristics than those ascribed to Mesoarchaean lode gold deposits. This suggests similar mineralization processes for mid- and Mesoarchaean lode gold deposits despite contrasting fluid–rock interaction histories. However, in regard to the protracted history documented in the Warrawoona Syncline, we question the robustness of the epigenetic crustal continuum model, as ore-fluid characteristics equally support an epigenetic or a polyphased mineralization process.  相似文献   

Miocene tidal-influenced sedimentation to continental Pliocene sedimentation in the forebulge–backbulge depozones of the Beni–Mamore foreland Basin (northern Bolivia)     

Martin Roddaz  Stphane Brusset  Patrice Baby  Grard Hrail 《Journal of South American Earth Sciences》2006,20(4):351-368

Mio-Pliocene deposits of the forebulge–backbulge depozones of the Beni-Mamore foreland Basin indicate tidally to fluvially dominated sedimentation. Seven facies assemblages have been recognized: FAA–FAG. FAA represents a distal bottom lake assemblage, FAB and FAD are interpreted as tidal flat deposits, FAC and FAG are interpreted as fluvial systems, FAE sediments are deposited in a subtidal/shoreface setting, and FAG represents a meandering fluvial system. The identification of stratigraphic surfaces (SU, MFS, and MRS) and the relationship among the facies assemblages permit the characterization of several systems tracts: a falling-stage systems tract (FSST) followed by a lowstand systems tract (LST), a transgressive systems tract (TST), and a highstand systems tract (HST). The FSST and LST may have been controlled by the uplift of the Beni-Mamore forebulge, whereas TST may result from a quiescent stage in the forebulge. Subaerial unconformity two (SU2) records the passage from a tide-influenced depositional system to a fully continental depositional system. The Miocene tidal-influenced deposits in the Beni–Mamore Basin suggest that it experienced a connection, either with the South Atlantic Ocean or the Caribbean Sea or both.  相似文献   

The surface energy balance and the mixing height in urban areas—activities and recommendations of COST-Action 715     

Martin Piringer  Sylvain Joffre  Alexander Baklanov  Andreas Christen  Marco Deserti  Koen De Ridder  Stefan Emeis  Patrice Mestayer  Maria Tombrou  Douglas Middleton  Kathrin Baumann-Stanzer  Aggeliki Dandou  Ari Karppinen  Jerzy Burzynski 《Boundary-Layer Meteorology》2007,124(1):3-24

The specific problems of determining and simulating the surface energy balance (SEB) and the mixing height (MH) over urban areas are examined. The SEB and MH are critical components of algorithms and numerical models for the urban boundary layer, though the constituent parts of the SEB and the MH are not routinely measured by national weather services. Parameterisations are thus needed in applications. In this investigation, several recently developed algorithms and models for estimating the SEB and MH were applied to new datasets and assessed. Results are discussed in terms of the need for spatial resolution and the parameters needed to describe the urban atmosphere. Limitations of models are identified and recommendations for further development and observations are given. Having identified gaps in knowledge, key findings from new urban experiments and numerical modelling for the SEB and MH are given. The diurnal cycle for the SEB is significantly different from rural conditions—urban heat storage is needed in urban parameterisations. The urban MH is increased over the rural MH, as shown by several numerical schemes and careful sodar analyses. This work has been carried out within the COST-715 Action “Meteorology applied to urban air pollution problems (1998–2004). COST 715 reached a consensus proposing representatively sited measurements of meteorological parameters and turbulent fluxes above roof-tops, and recognised that such data are needed to improve numerical models of the urban surface processes.  相似文献   

Technosols made with various urban wastes showed contrasted performance for tree development during a 3-year experiment     

Patrice Cannavo  René Guénon  Gilles Galopin  Laure Vidal-Beaudet 《Environmental Earth Sciences》2018,77(18):650

Vegetation in urban areas is generally living in a stress-inducing environment. Sustaining good soil quality is crucial to improve tree development and heath in such (artificial) environment. This study investigates the dynamics of the physico-chemical properties of Technosol, and compares tree development performances in various waste mixtures. A 3-year experiment was conducted with Acer platanoïdes L. grown in three distinct constructed soils, in three replicates, in 0.480-m³ lysimeters in Angers (France). Four combinations of artefacts were studied either as “growing material” (GM) or “structural material” (SM). Three different SMs were used: (1) a mixture of fine mineral material, demolition rubble and green waste (SM-DR/GW), (2) a mixture of fine mineral material, track ballast and sewage sludge (SM-TB/SS), and (3) the SM currently used by Angers city for green space settlements (SM-CT). Waste characteristics and mixing proportions both affected tree development. Physical properties were not a limiting factor for tree development, despite a relatively low soil water reservoir due to high stone content. Moreover, the chemical properties of the materials, more particularly low water pH and CEC, led to poor tree development in SM-CT, whereas the other two SMs did not affect tree development. SM-TB/SS was the most suitable constructed soil after 3 years because it exhibited satisfactory soil nutrient contents that promoted the best tree crown quality. Waste mixtures can sustain soil functions for tree development. As for urban street tree pits that are 2–8 m³ in volume, soil water, and nutrient autonomy should satisfactorily sustain tree development.  相似文献