Changes in storminess and surges in western France during the last century

French meteorological data provide some information on wind direction since 1890. Since 1951, wind speed and direction have been digitised every three hours in many stations. The Brest tide gauge has recorded hourly sea levels since 1860, thus enabling hourly surges to be calculated and studied. This set of data has been organised into a data base and analysed in order to recognize evolution and trends. Strong winds are increasing in frequency in the western part of Brittany and decreasing in Normandy and Pays de Loire. Surges associated with these winds do present a slight decreasing trend. A more precise analysis allows to distinguish between southerly winds, which are slightly decreasing, and strong winds from other directions, which display a more or less important increase in frequency. The analysis shows trends that may be linked to the global circulation pattern, and that result in a new spatial distribution of winds on western France.     

The CMEKF Method for Sub-Sea Pipeline Monitoring and Leak Detection

1 .IntroductionIdentificationofaleakingflowlinerepresentsaspecialchallengetoboththeoilandgasindustryandregulators .While ,historically ,thenumberofcasesofshallowwaterreleasefromflowlinesisex tremelysmall,deepwaterflowlinesoperateunderconditionsrarelyencounteredinpreviousdevelopmentschemes .Theremotenessofthedeepwaterpipeline ,coupledwithanumberofcomplexinteractionsbe tweenthereleasedfluidsandthedeepwaterenvironment,effectivelyeliminatesmostexternaldetectionmethods (Scott,1 999) .Thecauseoflea…     

Neogene exhumation and relief evolution in the eastern Betics (SE Spain): Insights from the Sierra de Gador

The Betics are a key area to study an orogenic landscape disrupted by late‐orogenic extension. New low‐temperature thermochronology (LTT) data (AHe and AFT) coupled with geomorphic constraints in the Sierra de Gador (Alpujarride complex) are used to reconstruct the cooling history and evolution of relief during the Neogene. We document three stages: (1) a fast cooling event between 23 and 16 Ma associated with the well‐known extensive tectonic exhumation of the Alpujarride unit, (2) a period of slow cooling between 16 and 7.2 Ma related to a planation event and (3) a post‐7.2 Ma surface uplift associated with the inversion of the Alboran domain undetected by LTT. The planation event followed by this late uplift can explain the occurrence of inherited low‐relief surfaces overlain by Tortonian–Messinian platform deposits at the top of the range. Finally, we propose that the Sierra de Gador is a more transient landscape than the nearby Sierra Nevada.     

Along-strike variations of P–T conditions in accretionary wedges and syn-orogenic extension,the HP–LT Phyllite–Quartzite Nappe in Crete and the Peloponnese

Syn-orogenic detachments in accretionary wedges make the exhumation of high-pressure and low-temperature metamorphic rocks possible with little erosion. The velocity of exhumation within the subduction channel or the accretionary complex, and thus the shape of P–T paths, depend upon the kinematic boundary conditions. A component of slab retreat tends to open the channel and facilitates the exhumation. We document the effect of slab retreat on the shape of P–T paths using the example of the Phyllite–Quartzite Nappe that has been exhumed below the Cretan syn-orogenic detachment during the Miocene in Crete and the Peloponnese. Data show a clear tendency toward colder conditions at peak pressure and during exhumation where the intensity of slab retreat is larger. This spatial evolution of P–T gradient is accompanied with an evolution from a partly coaxial regime below the Peloponnese section of the detachment toward a clearly non-coaxial regime in Crete.     

Der physikalische Zusammenhang zwischen der statischen Abplattung und dem inneren Aufbau der Erde auf der hypothetischen Grundlage einer sechsparametrigen Gleichgewichtsfigur

Zusammenfassung Es wird eine allgemeine Theorie der mehrparametrigen Gleichgewichtsfiguren entwickelt. Die Gleichgewichtsbedingung wird folgendermaßen formuliert: 1. Das Dichtegesetz ist streng individuell. 2. Jede Gleichgewichtsfigur besteht aus mehreren, durch Diskontinuitätsflächen getrennten Teilen, deren jeder das Dichtegesetz der einparametrigen Gleichgewichtsfiguren aufweist oder homogen ist. 3. Bei Entblätterung der Figur bis zur innersten Diskontinuitätsfläche resultiert ein null oder einparametriger Kern. Für das Normalsphäroid der Erde wird ein dreiteiliges Modell zugrundegelegt, bestehend aus einer homogenen Wasserhülle, einem heterogenen Mantel und einem ebensolchen Kern. Nach Abhebung des Ozeans verbleibt eine vierparametrige Festerde, wobei die Kernoberfläche in 2900 km Tiefe angenommen wird. Da zur eindeutigen Lösung zwei Bestimmungsstücke fehlen, erhält man ² Lösungen, deren Gültigkeitsbereich durch drei lineare Reihen von Grenzfiguren abgeschlossen ist: eine Figurenreihe mit homogenem Kern und heterogenem Mantel, eine Reihe mit homogenem Mantel und heterogenem Kern und eine Reihe mit verschwindendem Dichtesprung an der Kernoberfläche. Die drei Ecken des Feldes sind durch folgende Figuren gegeben:a) einWiechert'sches Modell, bestehend aus einem homogenen Mantel und einem homogen Kern; diese Figur weist das maximale HauptträgheitsmomentC auf.b) die GrenzfigurB mit homogenem Kern und verschwindendem Dichtesprung, welche das minimale Trägheitsmoment hat.c) die GrenzfigurC mit homogenem Mantel und dem Dichtesprung Null. Innerhalb der empirischen Unsicherheit fällt das aus der dynamischen und statischen Abplattung der wirklichen Erde für die Festerde berechnete Hauptträgheitsmoment mit dem Minimalwert der FigurB zusammen. Es scheint demnach, daß die wirkliche Erde durch einen minimalen Drehimpuls ausgezeichnet ist, womit aber gleichzeitig der Kern homogen sein muß und an der Kernoberfläche kein Dichtesprung auftreten dürfte.

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Summary A general theory of multiparameter figures of equilibrium is developed. The condition of equilibrium is formulated as follows: 1. The density-law is strictly individual. 2. Each figure of equilibrium consists of several parts separated by surfaces of discontinuity, each of which has the density-law of the one parametric figures of equilibrium or is homogeneous. 3. Peeling off the figure to the lowest surface of discontinuity results a zero- or a one parametric core. For the normal spheroid of the earth a three-partite model consisting of a homogeneous water-cover, a heterogeneous mantle and of such a core is taken as basis. After peeling off the ocean a four-parametric solid earth remains, assuming the depth of the surface of the core in 2900 km. As for an unequivocal solution two data are lacking, we find ² solutions the domain of which is separated by three linear series of boundary-figures: a series of figures with homogeneous core and heterogeneous mantle, a series of figures with homogeneous mantle and heterogeneous core and a series with vanishing difference of density on the surface of the core. The three corner points of this field are represented by following figures:a) aWiechert-model consisting of a homogeneous mantle and a homogeneous core; this figure has the maximum of moment of inertiaC. b) the boundary figureB with homogeneous core and vanishing difference of densities, which has the minimum ofC. c) the boundary figure with homogeneous mantle and also vanishing difference of densities on the surface of the core. Within the empirical uncertainty the moment of inertiaC calculated from the dynamic and static flattening of the real earth coincides with the minimum value of figureB. Therefore it seems that the real earth is distincted by the minimum moment of rotation, in which case simultaneously the core must be homogeneous and the difference of density on the core's surface must vanish.

     

S(IV) Autoxidation in Atmospheric Liquid Water: The Role of Fe(II) and the Effect of Oxalate

The reactivity of dissolved iron compounds towards different pollutants and photooxidants in atmospheric liquid water depends upon the oxidation state and speciation of iron. Our measurements of the oxidation state of dissolved iron eluted from aerosol particles (Dae: 0.4–1.6 m) collected in the urban atmosphere of Ljubljana showed that a large fraction of the iron content is present as Fe(II). The concentration ratio [Fe(II)]/[Fe(III)] varied between 0.9 and 3.1. The kinetics of S(IV) autoxidation catalyzed by Fe(II) under the conditions representative for acidified atmospheric liquid water and the influence of oxalate on this reaction under dark conditions was investigated. The reaction rate is the same if Fe(II) or Fe(III) is used as a catalyst under the condition that Fe(II) can be oxidized in Fe(III), which is the catalytically active species. Oxalate has a strong inhibiting effect on the S(IV) autoxidation in the presence of Fe(II). The reaction is autocatalytic with an induction period, that increases with higher concentrations of oxalate. The inhibiting effect of oxalate differs according to whether iron is initially in the Fe(II) or Fe(III) state. However, in both cases the inhibition by oxalate is a result of the formation of complexes with the catalyst.     

水泥粉体深层喷射搅拌桩复合地基处理及其效果

水泥粉体深层喷射搅拌桩与干振碎石桩〔１〕、干振灰土桩等一样,也是处理松软地基土的一种有效方法。但与干振碎石桩等其他挤密型复合地基处理方法不同,水泥粉体深层喷射搅拌桩属于摩擦桩型。由于天然地基土对桩体的侧摩擦力和端阻力的共同作用,使复合地基的承载力大幅度提高。然而人们普遍认为,水泥粉体深层喷射搅拌桩法复合地基处理不能解决场地土的液化问题。本文通过工程实例和瑞雷波检测结果,证实了该方法处理的复合地基,除了承载力有较大幅度的提高外,地基土的抗液化能力也可以得到相应的加强。