Exploring the link between climate change and migration   总被引：1，自引：1，他引：0  

Sabine L. Perch-Nielsen  Michèle B. Bättig  Dieter Imboden 《Climatic change》2008,91(3-4):375-393

Previous research has postulated that climate change will lead to mass migration. However, the linkages postulated between the two have not been explicitly demonstrated but have rather been derived from ‘common sense’. In this paper, the connection between climate change and migration via two mechanisms, sea level rise and floods, is investigated and depicted in conceptual models. In both cases, a connection can be traced and the linkages are made explicit. However, the study also clearly shows that the connection is by no means deterministic but depends on numerous factors relating to the vulnerability of the people and the region in question.  相似文献   

Changes in climate extremes, variability and signature on sub-Antarctic Marion Island     

Peter C. le Roux  Melodie A. McGeoch 《Climatic change》2008,86(3-4):309-329

The ecological consequences of climate change are determined by many climate parameters, not just by the commonly investigated changes in mean temperature and rainfall. More comprehensive studies, including analyses of climate variability, extremes and aggregate changes in the climate system, can improve the understanding of the nature, and therefore possible consequences, of recent changes in climate. Here climate trends on the sub-Antarctic Marion Island are documented (between 1949 and 2003) in more detail than previously. Significant trends in biologically-relevant, and previously unexplored, parameters were observed, and the potential ecological consequences of these changes discussed. For example, the decline in precipitation experienced on the island comprises a trend for longer dry spells punctuated by fewer and smaller precipitation events. This more detailed understanding of the island’s drying trends enables more accurate predictions about its impacts, including, for example, particularly severe effects on plant species growing in soils with poor water-holding capacity. Therefore, in addition to changes in average conditions, more inclusive climate analyses should also examine trends in climatic variability and extremes, for individual climate parameters as well as for the climate system as a whole.  相似文献   

Re-Os isotopic composition of peridotitic sulphide inclusions in diamonds from Ellendale, Australia: Age constraints on Kimberley cratonic lithosphere   总被引：3，自引：0，他引：3  

K.V. Smit  S.B. Shirey  A.P. le Roex 《Geochimica et cosmochimica acta》2010,74(11):3292-3306

Sulphide-bearing diamonds recovered from the ∼20 Ma Ellendale 4 and 9 lamproite pipes in north-western Australia were investigated to determine the nitrogen aggregation state of the diamonds and Re-Os isotope geochemistry of the sulphide inclusions. The majority of diamond studies have been based on diamonds formed in the sub-continental lithospheric mantle (SCLM) below stable cratons, whereas the Ellendale lamproites intrude the King Leopold Orogen, south of the Kimberley craton. The sulphide inclusions consist of pyrrhotite-pentlandite-chalcopyrite assemblages, and can be divided into peridotitic and eclogitic parageneses on the basis of their Ni and Os contents. A lherzolitic paragenesis for the high-Ni sulphide inclusions is suggested from their Re and Os concentrations. Regression analysis of the Re-Os isotope data for the lherzolitic sulphides yields an age of 1426 ± 130 Ma, with an initial ¹⁸⁷Os/¹⁸⁸Os ratio of 0.1042 ± 0.0034. The upper limit of the uncertainty on the ¹⁸⁷Os/¹⁸⁸Os initial ratio gives a Re depletion age of 2.96 Ga, indicating the presence of SCLM beneath Ellendale since at least the Mesoarchaean, with the lherzolitic diamond-forming event much younger and unrelated to the craton keel stabilisation. The nitrogen aggregation state of the diamonds and calculated mantle residence temperatures suggest an origin and storage of the Ellendale diamonds in a stable cratonic SCLM, consistent with the King Leopold Orogen being cratonised by about 1.8 Ga. The diamonds do not show evidence for pervasive deformation or platelet degradation, which suggests that the diamonds had a relatively undisturbed 1.4 billion year mantle storage history.  相似文献   

Interaction between tectonic and erosion processes on the morphogenesis of an Alpine valley: geological and geophysical investigations in the lower Romanche valley (Belledonne massif, western Alps)     

Olivier Le Roux  Stéphane Schwartz  Jean François Gamond  Denis Jongmans  Pierre Tricart  Michel Sebrier 《International Journal of Earth Sciences》2010,99(2):427-441

In the Belledonne massif, the steep Paleozoic Belledonne Middle Fault (BMF) separates micaschists, displaying numerous landslides, from amphibolites. The massif is incised by the lower Romanche river valley. When crossing the BMF, the valley widens into a lozenge-shaped basin recently interpreted as an active pull-apart type structure associated with a major N110 striking Quaternary fault. Multidisciplinary investigations were carried out in the basin to check if this model has implications on the seismic and landslide hazard assessment. This study demonstrated the existence of a N80 sinistral strike slip Séchilienne Fault Zone (SFZ). This fault zone is suspected to offset the BMF by 375 m across the basin. Geophysical experiments revealed that the bedrock depth increases strongly in the basin, up to 350 m. Our study invalidates the active pull-apart origin of the basin and suggests it results from Quaternary glacial and fluvial erosion processes, magnified by the intersection of two inherited structures, the BMF and the SFZ.  相似文献   

Fractures,hydrothermal alterations and permeability in the Soultz Enhanced Geothermal System     

Béatrice Ledésert  Ronan Hebert  Albert Genter  Danièle Bartier  Norbert Clauer  Céline Grall 《Comptes Rendus Geoscience》2010,342(7-8):607-615

Borehole studies of the Soultz-sous-Forêts granite are dedicated to deep geothermics. The hydraulic properties of the reservoir are mainly controlled by the occurrence of some altered cataclastic shear zones showing a low natural permeability characterized by the occurrence of brines. Those zones show a fracture cluster organisation with sealed fractures of various types (post-filled joints, sheared fractures, veins). The main hydrothermal deposits observed within the permeable zones are geodic quartz, carbonates, illite and more locally sulphides. The fracture wall–rocks are intensely transformed: dissolution of igneous minerals, crystallization of new minerals, porosity and permeability increase. It is important to characterize the newly-formed minerals in order to choose the reagents used to improve the permeability of the exchanger by chemical stimulations. This article represents a synthesis of the studies completed by the authors between 1990 and 2008 on the fracture networks, hydrothermal alterations and mineral crystallizations they induced and data about the flow pathways in the exchanger.  相似文献   

Structural features of South-Adamawa (Cameroon) inferred from magnetic anomalies: Hydrogeological implications     

Constant Tatchum Noutchogwe  Fidèle Koumetio  Eliezer Manguelle-Dicoum 《Comptes Rendus Geoscience》2010,342(6):467-474

Structural directions of the southern part of the Adamawa plateau in Cameroon are highlighted by filters applied on the magnetic anomaly map. Determination of the magnitude maxima of (1) the horizontal gradient of the field reduced to the pole, and (2) the analytic signal, allowed a map to be produced showing various lineaments interpreted as the fault system of the studied area. In particular, the faults on the shaded relief map of the horizontal gradient magnitude suggest a slide to the left of the Foumban shear zone in the studied area. Interpretation of the observed anomaly along a profile directed SSE-NNW shows the presence of a magnetized body considered as an intrusion into the granitic basement of probably basaltic volcanic rocks, put in place during the reactivation of the Foumban shear zone. In addition, the observed correlation between the mapped structural directions, the sites of thermo-mineral springs and the hydrographical network shows that the results of this study will be helpful for further hydrogeological research in the studied area.  相似文献   

Plasma Jet Experiments Using LULI 2000 Laser Facility     

B. Loupias  E. Falize  M. Koenig  S. Bouquet  N. Ozaki  A. Benuzzi-Mounaix  C. Michaut  M. Rabec le Goahec  W. Nazarov  C. Courtois  Y. Aglitskiy  A. YA. Faenov  T. Pikuz 《Astrophysics and Space Science》2007,307(1-3):103-107

We present experiments performed with the LULI2000 nanosecond laser facility. We generated plasma jets by using specific designed target. The main measured quantities related to the jet such as its propagation velocity, temperature and emissive radius evolution are presented. We also performed analytical work, which explains the jet evolution in some cases.  相似文献   

Ubiquitination and carbonylation as markers of oxidative-stress in Ruditapes decussatus.     

Suze Chora  Brian McDonagh  David Sheehan  Mireille Starita-Geribaldi  Michèle Roméo  Maria J Bebianno 《Marine environmental research》2008,66(1):95-97

Environmental pollutants, such as metals, are widespread in aquatic environments and can lead to the formation of reactive oxygen species (ROS). ROS are highly toxic in marine species since they can cause serious reversible and irreversible changes in proteins including ubiquitination and modifications such as carbonylation. This study aimed to confirm the potential of ubiquitination and carbonylation as markers of oxidative stress in the clam Ruditapes decussatus (Veneroida, Veneridae) exposed to cadmium (40 microg/L). After 21 days of exposure clams were dissected into gills and digestive gland. Cytosolic proteins of both tissues were separated by two-dimensional electrophoresis (2-D SDS-PAGE) and analysed by immunobloting. Higher ubiquitination and carbonylation levels were in digestive gland of contaminated organisms. These results confirm the potential of ubiquitination and carbonylation as a sensitive and specific marker of oxidative stress in marine bivalves. In this approach, changes in protein structure provide options for affinity selection of sub-proteomes for 2D SDS-PAGE, simplifying the detection of protein biomarkers using proteomic approach.  相似文献   

阿尔金断裂晚新生代左旋走滑位错的地质新证据   总被引：20，自引：5，他引：20  

张岳桥  陈正乐  杨农 《现代地质》2001,15(1):8-12

通过对沿阿尔金断裂中段 (位于东经 88°至 92°)发育的晚第三纪走滑盆地沉积历史和走滑变形过程的野外观测以及对第四纪索尔库里盆地形成和演化过程的沉积环境复原的分析 ,提出了阿尔金断裂中段晚新生代左旋走滑位错的地质新证据。研究表明 ,晚第三纪走滑盆地经历了中新世晚期至上新世早期斜张走滑拉分和上新世晚期以来左旋错动的演化过程 ,沉积体沿断裂的错位分布特征指示至少发生了 80 km的左旋走滑位错。发育于阿尔金山链内部的索尔库里盆地起源于晚第三纪早期强烈的侵蚀作用 ,成为柴达木盆地快速沉积的主要物源区。该侵蚀盆地于中晚更新世闭合并演化成一个独立的沉积盆地。通过侵蚀盆地外流通道的复原指示阿尔金断裂自晚第三纪以来累积了 80～ 1 0 0 km的左旋位错。在此基础上 ,结合穿越断裂构造的 级区域水系形成的洪积裙宽度和主干河道沿断裂迹线的拐折长度 ,探讨了阿尔金断裂晚新生代左旋走滑位错量沿走向分布的特征 ,估算了左旋走滑速率  相似文献   

Palaeomagnetic dating of widespread remagnetization on the southeastern border of the French Massif Central and implications for fluid flow and Mississippi Valley-type mineralization     

Bernard Henry  Henri Rouvier  Maxime le Goff  David Leach  Jean-Claude Macquar  Jacques Thibieroz  Michael T. Lewchuk 《Geophysical Journal International》2001,145(2):368-380

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