Victims from volcanic eruptions: a revised database   总被引：2，自引：1，他引：1  

J.-C. Tanguy  C. Ribière  A. Scarth  W. S. Tjetjep 《Bulletin of Volcanology》1998,60(2):137-144

 The number of victims from volcanism and the primary cause(s) of death reported in the literature show considerable uncertainty. We present the results of investigations carried out either in contemporary accounts or in specific studies of eruptions that occurred since A.D. 1783. More than 220 000 people died because of volcanic activity during this period, which includes approximately 90% of the recorded deaths throughout history. Most of the fatalities resulted from post-eruption famine and epidemic disease (30.3%), nuées ardentes or pyroclastic flows and surges (26.8%), mudflows or lahars (17.1%), and volcanogenic tsunamis (16.9%). At present, however, international relief efforts might reduce the effects of post-eruption crop failure and disease, and at least some of the lahars could be anticipated in time by adequate scientific and social response. Thus, mitigation of hazards from pyroclastic flows and tsunamis will become of paramount importance to volcanologists and civil authorities. Received: 3 August 1997 / Accepted: 10 April 1998  相似文献   

Impact de la vie benthique sur la genèse de nodules calcaires dans les black shales     

Jean-Gabriel Bréhéret  Micheline Hanzo  Abderrazzak El Albani  Agnès Iatzoura 《Comptes Rendus Geoscience》2004,336(15):1355-1362

The study of calcareous nodules from four organic-rich black shale series allows us to suggest a prominent part for benthic organisms in creating heterogeneities in the sediment, thus favouring microbially mediated early diagenesis based on organic matter consumption. To cite this article: J.-G. Bréhéret et al., C. R. Geoscience 336 (2004).  相似文献   

Weathering processes on the rock surface in natural outcrops: the case of an ancient marble quarry (Belevi, Turkey)     

M. Garcia-Vallès  C. Urzì  M. Vendrell-Saz 《Environmental Geology》2002,41(8):889-897

. Weathering and mineralogical processes observed in a marble quarry in Turkey are compared with similar processes occurring on monument surfaces. Patina formations (microstromatolitic, microlaminated, monolayered) as well as destructive processes (mainly biopitting and bioerosion) are associated with microbial colonisation of the rock surfaces and one influenced by microclimatic conditions. Patina stratification is independent of substrate rock, but is affected by the position and orientation of rock surfaces. The different layers formed by mineralisation processes may reflect the seasonality of climatic events and the consequent colonisation. Bio-deteriorative processes take place mainly when the climatic conditions cause the organisms to live below the surface.  相似文献   

Systematic use of trace elements in igneous processes   总被引：11，自引：0，他引：11  

J. F. Minster  C. J. Allègre 《Contributions to Mineralogy and Petrology》1978,68(1):37-52

This paper develops an application of the inverse method proposed by Allégre et al. (1977) and Minster et al. (1977). Using a set of trace element data in a suite of primary lavas, it is possible to statistically test whether the data can be described by batch partial melting. Once this is achieved, one can inverse the problem and calculate the parameters which govern the process, that is: the degrees of melting corresponding to each lava, the initial source concentrations and partition coefficients for each element. This is a non-linear, strongly underdetermined problem, but when the set of trace elements is restricted to REE, taking advantage of the fact that their properties are smoothly related, the problem can be overconstrained by assuming a set of poorly constrained model parameters. Information contained in the data and in the external constraints can then be estimated and used to build a strategy of data acquisition. From a table of mineral-liquid partition coefficients, the mineralogies of the source and of the material entering the liquid can be calculated. The method has been tested on synthetic data sets representing natural cases, and proved to converge towards the real solution even when a very poor definition of the external constraints is introduced.The calculations have been applied to REE data on Grenada basanitoids (Shimizu and Arculus, 1976). It is confirmed that these lavas can be derived by 4 to 17% batch partial melting of a garnet lherzolite source (7% gt, 23% cpx) that is relatively enriched in light REE. This result is discussed in relation with Nd and Sr isotopic composition data.  相似文献   

Systematic use of trace element in igneous process     

Claude J. Allègre  Michel Treuil  Jean-François Minster  Bernard Minster  Francis Albarède 《Contributions to Mineralogy and Petrology》1977,60(1):57-75

This paper describes an extended application of the Rayleigh distillation law to trace element behavior in a fractional crystallization sequence. Using a trace element with a very low bulk partition coefficient as a reference (as suggested by Anderson and Greenland, 1969, and extended by Treuil and Varet, 1973), we can derive bulk partition coefficients for other elements and, in turn, the mineralogical composition of the cumulates. Trace elements with large D, such as Ni and Cr, further constrain the system, and we can deduce the initial composition of the magma. An example of this technique is shown for Terceira Island in the Azores.Contribution IPGNS no 229Now at Dept. of Geological Sciences, California Institute of Technology, Pasadena, California, USA  相似文献   

U-Pb systematics in iron meteorites: Uniformity of primordial lead     

C. Göpel  G. Manhès  C.J. Allègre 《Geochimica et cosmochimica acta》1985,49(8):1681-1695

Pb isotopic compositions and U-Pb abundances were determined in the metal phase of six iron meteorites: Canyon Diablo IA, Toluca IA, Odessa IA, Youndegin IA, Deport IA and Mundrabilla An. Prior to complete dissolution, samples were subjected to a series of leachings and partial dissolutions. Isotopic compositions and abundances of the etched Pb indicate a contamination by terrestrial Pb which is attributable to previous cutting of the meteorite. Pb isotopic compositions measured in the decontaminated samples are identical within 0.2% and essentially confirm the primordial Pb value defined by Tatsumotoet al. (1973). These data invalidate more radiogenic Pb isotopic compositions published for iron meteorites, which are the result of terrestrial Pb contamination introduced mainly by analytical procedure. Our results support the idea of a solar nebula which was isotopically homogeneous for Pb 4.55 Ga ago. The new upper limit for U-abundance in iron meteorites, 0.001 ppb, is in agreement with its expected thermodynamic solubility in the metal phase.  相似文献   

Some remarks on the notions of ‘structure’ and ‘system’ in geographyAnmerkungen zur bedeutung der begriffe ‘struktur’ und ‘system’ in der geographieRemarques sur les notions de ‘structure’ et ‘systèmes’ en géographie     

O Dollfus  F Durand Dastès 《Geoforum》1975,6(2):83-94

The terms structure and system are used frequently in geography, but nevertheless they remain often imprecise in definition as do the concepts themselves. An attempt is made here to show how geographical structure, which is geographical space organised by a system, may have an operational value in research to the extent that it incorporates both chorological and taxonomic facts. These ‘geographical structures’ should not be confused with the structures of systems.First the system is considered as a set of sets: set of elements, set of the attributes of these elements, set of relationships between the elements, and an assemblage of relationships between the complete system and all exterior to the system. The inputs, and functioning of systems in geography are then discussed by reference to a model of the atmospheric circulation, and to a model of an agricultural system.The utilisation of the two concepts structure and system have facilitated explanation in geography.  相似文献   

EUVITA - an extreme UV imaging telescope array with spectral capability     

J. -L. Courvoisier  A. Orr  P. Bühler  A. Zehnder  R. Henneck  F. Stauffacher  J. Biakhowski  N. Schlumpf  W. Schoeps  A. Mchedlishvili  R. Sunyaev  V. Aref'ev  A. Yascovich  G. Babalyan  M. Pavlinsky  J. P. Delaboudinière  T. Carone  . Siegmund  J. Warren  D. Leahy  N. Salaschenko  J. Platonov 《Experimental Astronomy》1993,4(2):117-135

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Post-collisional melting of crustal sources: constraints from geochronology,petrology and Sr,Nd isotope geochemistry of the Variscan Sichevita and Poniasca granitoid plutons (South Carpathians,Romania)   总被引：1，自引：1，他引：0  

Jean-Clair Duchesne  Jean-Paul Liègeois  Viorica Iancu  Tudor Berza  Dmitry I. Matukov  Mihai Tatu  Sergei A. Sergeev 《International Journal of Earth Sciences》2008,97(4):705-723

The Sichevita and Poniasca plutons belong to an alignment of granites cutting across the metamorphic basement of the Getic Nappe in the South Carpathians. The present work provides SHRIMP age data for the zircon population from a Poniasca biotite diorite and geochemical analyses (major and trace elements, Sr–Nd isotopes) of representative rock types from the two intrusions grading from biotite diorite to biotite K-feldspar porphyritic monzogranite. U–Pb zircon data yielded 311 ± 2 Ma for the intrusion of the biotite diorite. Granites are mostly high-K leucogranites, and biotite diorites are magnesian, and calcic to calc-alkaline. Sr, and Nd isotope and trace element data (REE, Th, Ta, Cr, Ba and Rb) permit distinguishing five different groups of rocks corresponding to several magma batches: the Poniasca biotite diorite (P₁) shows a clear crustal character while the Poniasca granite (P₂) is more juvenile. Conversely, Sichevita biotite diorite (S₁), and a granite (S₂*) are more juvenile than the other Sichevita granites (S₂). Geochemical modelling of major elements and REE suggests that fractional crystallization can account for variations within P₁ and S₁ groups. Dehydration melting of a number of protoliths may be the source of these magma batches. The Variscan basement, a subduction accretion wedge, could correspond to such a heterogeneous source. The intrusion of the Sichevita–Poniasca plutons took place in the final stages of the Variscan orogeny, as is the case for a series of European granites around 310 Ma ago, especially in Bulgaria and in Iberia, no Alleghenian granitoids (late Carboniferous—early Permian times) being known in the Getic nappe. The geodynamical environment of Sichevita–Poniasca was typically post-collisional of the Variscan orogenic phase.  相似文献   

The stability of dipolar gyres on a beta-plane     

Steven Herbette  Antoine Hochet  Thierry Huck  Alain Colin de Verdière  Jérémy Collin  Frank Shillington 《地球物理与天体物理流体动力学》2014,108(5):479-502

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