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1.
Until the mid-1980s, transport policy was considered by many as one of the least successful domains of the European integration project. However, from the early 1990s onwards, there are clear signs of a single European transport policy, along with the accompanying implementation of infrastructure projects. What is the explanation for such a change in pace? This paper aims to offer insight in these processes by looking at the mechanisms which form and transform this policy domain. To understand the state of a policy domain and its dynamics over time an institutional approach is taken. Two concepts in political science, ‘policy arrangements’ and ‘supranational governance’ are combined and used as a framework to analyse the European transport policy domain. This analysis describes the development of several elements: organisations, rules, the transnational society, power, resources, and the central transport discourse. It demonstrates that all of these elements have developed from an intergovernmental setting towards a more supranational one. This development was slow in the first decennia when European transport policy was rather passive, but it picked up speed in the 1980s and 1990s. In the pivotal year of 1985, pressure from the transnational society resulted in a rapid change of the rules, the resources and the discourse. 相似文献
2.
Assessing the Vibrational Frequencies of the Cathedral of Cologne (Germany) by Means of Ambient Seismic Noise Analysis 总被引:1,自引:0,他引:1
Andreas Fäcke Stefano Parolai Sandra M. Richwalski Lothar Stempniewski 《Natural Hazards》2006,38(1-2):229-236
Ambient seismic noise measurements were conducted inside the Cathedral of Cologne (Germany) for assessing its frequencies
of vibration and for checking whether these occur in the range where soil amplification is expected. If this is the case,
damages may increase in case of an earthquake due to an increased structural response of the building. Analysis of the ratio
between the horizontal and vertical components of the spectra recorded at stations located inside the building as well as
the ratio between the corresponding components of the spectra recorded simultaneously inside the building and at a reference
station placed in the basement of the cathedral indicated several modes of vibration. Facilitated by these results an assessment
of the seismic vulnerability was attempted for a 2D ground motion scenario using the finite element method. 相似文献
3.
4.
Leon P. J. Kamp 《地球物理与天体物理流体动力学》2013,107(4):257-271
Abstract In the present paper the behavior of (internal) magneto-acoustic-gravity waves near the cusp resonance in a lossless, compressible, isothermal, stratified, electrically conducting atmosphere that is permeated by a uniform, nearly horizontal magnetic field is re-addressed (Kamp, 1989). The previously analyzed linear conversion of long acoustic-gravity waves into short magneto-acoustic waves that carry off the energy from the resonance region along the magnetic field, is re-analyzed with boundary layer techniques that are based on the smallness of the vertical component of the magnetic field. More specifically the existence of the so-called valve effect for the generated magneto-acoustic mode near the critical level is explicitly demonstrated and shown to be governed by two rivalling effects. 相似文献
5.
Dagmar Kieke Birgit Klein Lothar Stramma Monika Rhein Klaus Peter Koltermann 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(10):1656-1674
The variability of two modes of Labrador Sea Water (LSW) (upper and deep Labrador Sea Water) and their respective spreading in the interior North Atlantic Ocean are investigated by means of repeated ship surveys carried out along the zonal WOCE line A2/AR19 located at 43–48°N (1993–2007) and along the GOOS line at about 48–51°N (1997–2002). Hydrographic section data are complemented by temperature, salinity, and velocity time series recorded by two moorings. They have been deployed at the western flank of the Mid-Atlantic Ridge (MAR) in the Newfoundland Basin during 1996–2004. The analysis of hydrographic anomalies at various longitudes points to a gradual eastward propagation of LSW-related signals, which happens on time scales of 3–6 years from the formation region towards the MAR. Interactions of the North Atlantic Current (NAC) with the Deep Western Boundary Current (DWBC) close to Flemish Cap point to the NAC being the main distributor of the different types of LSW into the interior of the Newfoundland Basin. Comparisons between the ship data and the mooring records revealed that the mooring sites are located in a region affected by highly variable flow. The mooring time series demonstrate an elevated level of variability with eddy activity and variability associated with the NAC considerably influencing the LSW signals in this region. Hydrographic data taken from Argo profiles from the vicinity of the mooring sites turned out to mimic quite well the temporal evolution captured by the moorings. There is some indication of occasional southward flow in the LSW layer near the MAR. If this can be considered as a hint to an interior LSW-route, it is at least of minor importance in comparison to the DWBC. It acts as an important supplier for the interior North Atlantic, distributing older and recently formed LSW modes southward along the MAR. 相似文献
6.
Peter J. J. Kamp Fraka J. Harmsen Campbell S. Nelson Susan F. Boyle 《Sedimentary Geology》1988,60(1-4):173-195
Pliocene, non-tropical, widespread and locally thick (up to 100 m) limestones occur in Hawke's Bay, eastern North Island, where they are intimately associated with very thick ( > 5 km), terrigenous-dominated, Neogene sequences that formed in a tectonically active convergent margin setting. The non-tropical character of the limestones is shown unequivocally by (1) the complete dominance of skeletal calcarenites and calcirudites, (2) the occurrence of oyster banks as the only in situ organic structures, (3) the dominance of barnacles, epifaunal molluscs, bryozoans, echinoderms, foraminifers, brachiopods and calcareous red algae as skeletal components, and (4) the preponderance of calcite over aragonite in the mineralogy of the skeletal grains and cements. The abundance of barnacle fragments in the limestones, and the related exclusive occurrence of only one major organic association, a barnacle-(epifaunal) bivalve-bryozoan assemblage, is striking and unusual given the extent of the limestones. Pecten and oyster valves acted as substrates for barnacle attachment, and their growth was promoted by strong tidal paleocurrents that swept the depositional setting: a long (450 km), narrow (30–50 km) forearc basin seaway, which formed between an actively deforming subduction complex to the east and an uplifting structural ridge to the west. Synsedimentary deformation promoted limestone formation on the margins of the seaway by creating current-swept, clastic-free submarine ridges that acted as the sites of carbonate production. Tidal flows dispersed the carbonate constituents and organised them into a wide spectrum of tide-influenced, cross-bedded and horizontal structures. Most spectacular are occurrences of giant tabular cross-beds, with sets 10–40 m thick and foreset dips of 7–36°, some interpreted as the deposits of major sand bars on carbonate deltas marginal to the mouths of saddles traversing the rising antiforms, and others analogous to modern linear sand ridges. The small- to large-scale planar and trough cross-beds, and the horizontal and lenticular beds that are invariably associated with the giant cross-beds and dominate most sections, represent mainly the deposits of sand waves and sand sheets at inner- to mid-shelf depths in the seaway. 相似文献
7.
Edouard Bard Maurice Arnold H. Gte
stlund Pierre Maurice Patrick Monfray Jean-Claude Duplessy 《Earth and Planetary Science Letters》1988,87(4)
Radiocarbon measurements performed on seawater samples by means of accelerator mass spectrometry (AMS) enable to reduce by a factor of 2000 the water sample size needed for the14C measurements. Therefore no chemical treatment on board the oceanographic vessel is required. Seventy-four AMS14C determinations on samples collected in the tropical-equatorial Indian Ocean during the second leg of the INDIGO program (1986) are presented and compared with the β-counting results obtained during the same campaign and the GEOSECS program (1978). A pronounced reduction of the equatorial14C deficit suggests that substantial amounts of bomb-14C are associated with the westward flowing Pacific water which enters the Indian Ocean via passages through the Indonesia archipelago and/or to meridional mixing with14C-rich water of the southern subtropical gyre. 相似文献
8.
The Southern Alps are the topographic expression of late Cenozoic (<8 Ma ago) uplift of the crust of the leading edge of the Pacific plate in South Island, New Zealand. New fission track data on the basement exposed in the Southern Alps quantify the age, amount, and rate of rock uplift, and in combination with geomorphic parameters permit the construction of a new model of the geomorphic evolution of the Southern Alps. The model emphasizes the development over time and space of rock uplift, mean surface elevation, exhumation of crustal section, and relief. The earliest indications of mean surface uplift are between 4 and 5 Ma ago at the Alpine Fault. Mean surface uplift, which lagged the start of rock uplift, propagated southeastward from the Alpine Fault at a rate of 30 km/Ma. By about 4 Ma ago, exhumation had exposed greywacke basement adjacent to and east of the entire 300 km long central section of the Alpine Fault. At 3 Ma ago, greenschist was exposed in the southern parts of the Southern Alps near Lake Wanaka, and since then has become exhumed along a narrow strip east of the Alpine Fault. The model infers that amphibolite grade schist has been exhumed adjacent to the Alpine Fault only in the last 0·3 Ma. The age of the start of rock uplift and the amount and rate of rock uplift, all of which vary spatially, are considered to be the dominant influences on the development of the landscape in the Southern Alps. The Southern Alps have been studied in terms of domains of different rock uplift rate. At present the rate of rock uplift varies from up to 8–10 mm/a adjacent to the Alpine Fault to 0·8–1·0 mm/a along the southeastern margin of the Southern Alps. This spectrum can be divided into two domains, one northwest of the Main Divide where the present rock uplift rates are very high (up to 8–10 mm/a) and exceed the long-term value of 0·8–1·0 mm/a, and another to the southeast of the Main Divide where the long-term rate is 0·8–1·0 mm/a. A domain of no uplift lies immediately to the east of the Southern Alps, and is separated from them by a 1·0–1·5 km step in the basement topography. We argue that this spatial sequence of uplift rate domains represents a temporal one. The existing models of the geomorphic development of the Southern Alps—the dynamic cuesta model of J. Adams and the numerical model of P. Koons—are compared with the new data and evolutionary model. Particular constraints unrealized by these two earlier models include the following: the earlier timing of the start of rock uplift of the Southern Alps (8 Ma ago); the spatial variation in the timing of the start of rock uplift (8 Ma ago to 3 Ma ago); the lower long-term rock uplift rate (0·8–1·0 mm/a) of the Southern Alps for most of the late Cenozoic; the lag between the start of rock uplift and the start of mean surface uplift; and the patterns of the amounts of late Cenozoic rock uplift and erosion across the Southern Alps. 相似文献
9.
Dr. Lothar Hahn 《International Journal of Earth Sciences》1982,71(3):1041-1056
The tectonic movements which occurred in Thailand between the Permian and the Jurassic (Indosinian Orogeny) caused the uplifting and subsidence of areas which were dominant paleogeographic features during the Triassic. The strong orogenic movements during the Norian caused an alteration of the paleogeographic conditions.The two sedimentation cycles of the Triassic comprised a marine facies development from the Skythian to the early Norian and a terrestrial one from the later Norian to the Rhaetian/Liassic.The development of the facies and structure of the Triassic sediments, as well as the intrusion and effusion of igneous rocks, are due to the subduction of oceanic crust beginning in the Carboniferous and to the collision of the Eurasian with the Indochina Plate during the Norian.
Zusammenfassung Die zwischen Perm und Jura in Thailand auftretenden tektonischen Bewegungen (Indosinische Orogenese) führten zur Bildung von Hebungs- und Senkungsgebieten, die die Paläogeographie in der Trias beherrschten. Die starken orogenen Bewegungen im Nor führten zu einer Umgestaltung der paläogeographischen Verhältnisse.Die beiden während der Trias auftretenden Sedimentationszyklen bestehen aus einer marinen Faziesentwicklung vom Skyth bis zum unteren Nor und einer terrestrischen vom oberen Nor bis zum Rhät/Lias.Die fazielle und strukturelle Entwicklung der Triassedimente sowie die Intrusion bzw. Effusion von Eruptivgesteinen sind auf die seit dem Karbon erfolgende Subduktion ozeanischer Kruste und die Kollision der Eurasiatischen Platte mit der Indochinesischen Platte im Nor zurückzuführen.
Résumé Les mouvements tectoniques («Orogenèse Indosinienne») intervenus entre le Permien et le Trias en Thaïlande se sont traduits en soulèvements et affaissements qui ont dominé la paléogéographie du Trias. Les forts mouvements orogéniques du Norien ont conduit à transformer les rapports paléogéographiques.Les deux cycles sédimentaires du Trias consistent dans le développement d'un faciès marin du Scythien au Norien inférieur, et d'un faciès continental du Norien supérieur au Rhétien/Lias. L'évolution du faciès et de la structure des sédiments du Trias, l'intrusion et l'effusion des roches ignées sont attribuées à la subduction de la croute océanique consécutive au Carbonifère, et à la collision de la «Plaque Euroasiatique» avec la «Plaque Indochinoise» au Norien.
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10.
In adapting the prestack migration technique used in seismic imaging to the inversion of ground‐penetrating radar (GPR) from time‐ to depth‐sections, we show that the theoretical integral formulation of the inversion can be applied to electromagnetic problems, albeit with three assumptions. The first two assumptions concern the electromagnetic characteristics of the medium, primarily that the medium must be perfectly resistive and non‐dispersive, and the third concerns the antennae radiation pattern, which is taken to be 2D. The application of this adaptation of the inversion method is confirmed by migrating actual GPR measurements acquired on the test site of the Laboratoire Central des Ponts et Chaussées. The results show good agreement with the geometry of the structures in the medium and confirm that the possible departure from the assumption of a purely resistive medium has no visible effect on the information concerning the geometry of scattering and reflecting structures. The field experiments also show that prestack migration processing is sufficiently robust with regard to the assumption of a non‐dispersive medium. The assumption of a 2D antennae radiation pattern, however, produces artefacts that could be significant for laterally heterogeneous media. Nevertheless, where the medium is not highly laterally heterogeneous, the migration gives a clear image of the scattering potential due to the geometry of structural contrasts in the medium; the scatterers are well focused from diffraction hyperbolae and well localized. Spatial geometry has limited dimensional accuracy and positions are located with a maximum error equal to the minimum wavelength of the signal bandpass. Objects smaller than one wavelength can nevertheless be detected and well focused if their dielectric contrasts are sufficiently high, as in the case of iron or water in gneiss gravels. Furthermore, the suitability of multi‐offset protocols to estimate the electromagnetic propagating velocity and to decrease the non‐coherent noise level of measurements is confirmed. Our velocity estimation is based on the semblance calculation of multi‐offset migrated images, and we confirmed the relevance of this quantification method using numerical data. The signal‐to‐noise ratio is improved by summing multi‐offset results after the addition of random noise on measurements. Thus the adaptation of prestack migration to multi‐offset radar measurements significantly improves the resolution of the scattering potential of the medium. Limitations associated with the methods used here suggest that 3D algorithms should be applied to strongly laterally heterogeneous media and further studies concerning the waveform inversion are necessary to obtain information about the electric nature of the medium. 相似文献