The need for secure sites for such sensitive installations as nuclear power plants and radioactive waste storage has brought increasing significance to the study of the geodynamic processes of the Earth's crust. Among other Earth sciences, geomorphology in Czechoslovakia is also participating in the study of both planning and operating nuclear power station sites. The experience of Czech geomorphologists has shown that the geomorphological information is necessary part of the accurate prediction of events and time which can endanger the security of nuclear power plants, radioactive waste storages, pipelines and other large installations. Geomorphological mapping and morphostructural analysis are important tools for such studies. 相似文献
Riassunto Si determinano le precisioni con le quali possono venire osservate le deviazioni della verticale e si richiama l'attenzione su ciò quando si debbono interpretare le misure predette per prospezioni del sottosuolo.
Summary Measuring the deflections of the plumb-line the attainable precision is determined, in particular to investigations for geophysical prospecting.
Zusammenfassung Es wird für die Bestimmung der Lotabweichungen der erreichbare Genauigkeitsgrad untersucht, besonders im Hinblick auf Messungen zur Erforschung des Untergrundes.
On November 14, 2016, the northeastern South Island of New Zealand was hit by the magnitude Mw 7.8 Kaikōura earthquake, which is characterized by the most complex rupturing mechanism ever recorded. The widespread landslides triggered by the earthquake make this event a great case study to revisit our current knowledge of earthquake-triggered landslides in terms of factors controlling the spatial distribution of landslides and the rapid assessment of geographic areas affected by widespread landsliding. Although the spatial and size distributions of landslides have already been investigated in the literature, a polygon-based co-seismic landslide inventory with landslide size information is still not available as of June 2021. To address this issue and leverage this large landslide event, we mapped 14,233 landslides over a total area of approximately 14,000 km2. We also identified 101 landslide dams and shared them all via an open-access repository. We examined the spatial distribution of co-seismic landslides in relation to lithologic units and seismic and morphometric characteristics. We analyzed the size statistics of these landslides in a comparative manner, by using the five largest co-seismic landslide inventories ever mapped (i.e., Chi-Chi, Denali, Wenchuan, Haiti, and Gorkha). We compared our inventory with respect to these five ones to answer the question of whether the landslides triggered by the 2016 Kaikōura earthquake are less numerous and/or share size characteristics similar to those of other strong co-seismic landslide events. Our findings show that the spatial distribution of the Kaikōura landslide event is not significantly different from those belonging to other extreme landslide events, but the average landslide size generated by the Kaikōura earthquake is relatively larger compared to some other large earthquakes (i.e., Wenchuan and Gorkha).
Summary It is physiographically elaborated correlation among the volumetrical variations relates to the bottom Mediterranean Sea, occurred from 1824 to 1924, and the centurial continental-shelf sedimentation or water-level sea vertical variations of Italy and Tunisy, the neutral-line Cornaglia's, the axis of minima selection Thoulet's, the mud-line Murray's.It is too remarked the gross mistake of some geographer when the morphological confrontation it is limited linearly with only one dimension (coastlines variations) or surfacially with two dimensions (area's variations), not to esteeming of any account of the bathylithological synchronous variations, without orthodromical compensation of scale, if it is about of original maps differently dated. 相似文献
Zusammenfassung Die ersten tektonischen Vorstellungen legte 1669Nic. Steno in seinem Prodromus nieder. Seine Beobachtungen an horizontalen und geneigten Schichten führten später zu dem Begriffe der orogenetischen Diskordanzen. L.Élie de Beaumont ist sein direkter Nachfolger geworden, während J.Hutton ganz unabhängig von beiden den Diskordanzbegriff entwickelte. Die neptunistische Lehre von A. G.Werner ging von einem primären, von Wasserfluten geschaffenen Relief der Erdoberfläche aus, das überschichtet wurde. Doch auchWerner dachte daneben ebenfalls an große Höhlen, deren Decken einbrechen würden. Die neptunistischen Schwierigkeiten ergaben sich aus der Unmöglichkeit einer vertikalen Sedimentation von primär senkrecht gestellten Schichten. Die Anfänge der Erforschung der Tektonik des Rheingrabens werden dargelegt, und es wird besonders gezeigt, daßÉlie de Beaumont, der 1836 von einem eingebrochenen Gewölbe sprach, schon vorher Kenntnis eines eingebrochenen Gewölbes von Island und eines Schichtgewölbes von Württemberg über Schwarz wald — Vogesen nach Lothringen hatte. Die Zeit des Einbruches legteÉ. de Beaumont irrtümlich in die Zeit des Buntsandsteins.Theorien der Gebirgsbildung wurden mit L. v.Buch's Erhebungstheorie und geognostischen Gebirgssystemen um zwei weitere Ideen 1824–1835 erweitert.Élie de Beaumont baute diese Theorie sehr aus und sprach von Revolutionen der Erdkruste (1829). Die Faltengebirge fanden in J.Thurmann (1832) ihren ersten gründlichen Bearbeiter, der am Beispiel des Faltenjuras nachwies, daß doch nur Horizontalkräfte am Werke gewesen sein können und die Erhebungstheorie L. v.Buch's für diese Gebirgsarten keine Erklärung bringe. Zum Schlusse wird die Geschichte des Geologenkompasses gebracht.
Nic. Steno was the first who developed tectonic ideas in his Prodromus in 1669. His observations in the surroundings of Firenze (Italy) led him to the notion what nowadays is called a discordance by orogeny. He was followed by the French L.Élie de Beaumont, while the Scotchman J.Hutton developed this term of tectonic discordance quite independently of both.The neptunic theory of A. G.Werner in Freiberg (Saxony) started from the idea that the primary relief of the surface of the earth was formed by floods and covered with sediments. Furtheron he assumed large caves, the tops of them having broken down, explaining in this manner very inclined strata. The difficulties in this neptunic theory resulted from the fact that it was impossible to account for a sedimentation in a vertical line as seen in vertical layers.The author gives a survey of the first researches in the tectonics of the Rhinegraben and shows thatÉlie de Beaumont, who in 1836 mentioned the breakdown of the central ridge of a vault, so forming the rift-valley, had already some information of such a pressure arch in Iceland and of a second one stretching from Würtemberg via Black Forest—Vosges to Lorraine.Élie de Beaumont misdated the collapse of this large vault, stating erroneously the time of Buntsandstein (=New Red Sandstone).Between 1824 and 1835 L. v.Buch developed two further theories on orogenesis, that of the elevation-crater hypothesis and that of the geognostic systems of mountains. É.de Beaumont completedBuch's theory and in 1829 he spoke of revolutions of the earth's crust.The first who thoroughly researched the Swiss Jura was J.Thurmann. Quoting the folded strata of this region as an example he proved that only horizontal stresses could have been responsible for the formation of these mountains and that the elevation-crater hypothesis of L. v.Buch acting only with vertical forces could not give any explanation for it.Finally the author recapitulates the history of the geologist's compass.
Résumé Les premières conceptions tectoniques ont été exposées en 1669 par N.Steno dans son « Prodrome ». Ses observations sur des strates horizontales ou inclinées ont conduit ultérieurement à la notion de discordances orogéniques. L.Élie de Beaumont fut son successeur direct, cependant que J.Hutton, tout à fait indépendamment des deux premiers développa la notion de discordance. La théorie neptuniste de A. G.Werner se basait sur l'existence préalable d'un relief terrestre créé par les flots et qui aurait été noyé sous les strates des dépôts ultérieurs. Pourtant, dans un autre ordre d'idées,Werner pensait aussi à l'existence d'immenses grottes dont les toits s'effondreraient. Les neptunistes éprouvèrent des difficultés résultant de l'impossibilité d'expliquer des couches redressées par une sédimentation verticale. L'auteur expose les débuts des recherches sur la tectonique du fossé rhénan et montre en particulier qu'Élie de Beaumont, qui parla en 1836 d'une voûte effondrée avait déjà auparavant eu connaissance d'une voûte effondrée en Islande et d'une voûter structurale allant du Wurttemberg en Lorraine par-dessus la Forêt-Noire et les Vosges. Par erreur,É de Beaumont plaça le moment de cet effondrement à l'époque du grès bigarré.Avec la théorie des soulèvements et des orogènes géognostiques L. v.Buch enrichit de 1824–1835 les théories orogéniques de deux concepts supplémentaires.Élie de Beaumont les développa et parla de révolution de la croûte terrestre (1829). Les premières recherches approfondies sur les chaînes plissées sont dues à J.Thurmann (1832) qui, d'après l'exemple du Jura plissé, démontra que seules des forces horizontales ont pu avoir été à l'oeuvre et que la théorie des soulèvements de L.von Buch n'apportait pas d'explication pour les chaînes de ce type.Pour terminer, l'auteur expose l'histoire de la boussole du géologue.
Summary Intensity forecasts of a hurricane are shown to be quite sensitive to the initial meso-convective scale precipitation distributions. These are included within the data assimilation using a physical initialization that was developed at Florida State University. We show a case study of a hurricane forecast where the inclusion of the observed precipitation did provide reasonable intensity forecasts. Further experimentation with the inclusion or exclusion of individual meso-convective rainfall elements, around and over the storm, shows that the intensity forecasts were quite sensitive to these initial rainfall distributions. The exclusion of initial rain in the inner rain area of a hurricane leads to a much reduced intensity forecast, whereas that impact is less if the rainfall of an outer rain band was initially excluded.Intensity forecasts of hurricanes may be sensitive to a number of factors such as sea surface temperature anomalies, presence or absence of concentric eye walls, potential vorticity interactions in the upper troposphere and other environmental factors.This paper is a sequel to a recent study, Krishnamurti et al., 1997, on the prediction of hurricane OPAL of 1995 that was a category III storm over the Gulf of Mexico. In that study we showed successful forecasts of the storm intensity from the inclusion of observed rainfall distributions within physical initialization. In that paper we examined the issues of diabatic potential vorticity and the angular momentum in order to diagnose the storm intensity. All of the terms of the complete Ertel potential vorticity equation were evaluated and it was concluded that the diabatic contributions to the potential vorticity were quite important for the diagnosis of the storm's intensity. The present paper addresses some sensitivity issues related to the individual mesoconvective precipitating elements.With 4 Figures 相似文献
Zusammenfassung Die einzelnen tektonischen Einheiten des Iran werden in ihrer faziellen und strukturellen Entwicklungsgeschichte dargestellt. Fazies und Paläogeographie sprechen dafür, daß vom Infrakambrium bis in die Trias der gesamte Raum zwischen dem Persischen Golf und dem Elburs-Gebirge eine einheitliche Entwicklung genommen hat. Eine zusammenhängende Plattformsedimentation in Schelffazies kennzeichnet dieses Gebiet während des gesamten Zeitraums. Es ist ein Teil Gondwanas. Paläomagnetische Befunde stützen diese Aussage. Ozeanische Kruste und damit Hinweise auf die Tethys als eine strukturelle Einheit fehlen während dieser Zeit in diesem Gebiet. Lediglich als Faunenprovinz in Flachmeerfazies ist sie wirksam. Das offene Meer lag vom Infrakambrium bis zur oberen Trias im Norden. In der Trias tritt mit einer Heraushebung, die mit tiefgreifender Lateritisierung verbunden ist, und einer anschließenden Transgression ein grundlegender Wechsel des geodynamischen Regimes ein. Von jetzt an erfolgen die Ingressionen in den Iran von Süden. Eine engräumige fazielle Differenzierung setzt ein. Kontinental beeinflußte Sedimente im Jura zeigen, daß im Iran ein Hochgebiet entstanden ist. Gleichzeitig tretenwahrscheinlich in Anlehnung an langlebige Geosuturen — Ophiolith-Radiolarit-Zonen auf, die als das Ergebnis intrakratonischer Zerbrechung gedeutet werden. Die Ingressionen gehen wahrscheinlich von Tiefseerinnen aus, in denen auch die Ophiolithe konzentriert sind. Der Aufstieg des ophiolithischen Materials an die Oberfläche erfolgte entlang von Linien, an denen sich flach geneigte Unterschiebungen von Kruste unter Kruste ereigneten. Dabei kam es zu erheblichen Krustenverkürzungen. Möglicherweise fällt der Umbruch des tektonischen Regimes in der Obertrias mit der Plattenkollision Arabia-Iran/ Eurasia zusammen. Die Grenze zwischen Arabia-Iran und Eurasia liegt aber nicht im Gebiet des Persischen Golfes und der Zagros-Ketten, sondern muß nördlich des Elburs-Gebirges gesucht werden.
The individual tectonic units of Iran are represented with respect to the history of the development of their facies and structure. Facies and paleogeography indicate that the entire area between the Persian Gulf and the Elburz Mountains had a uniform development until the Triassic. During the whole period a coherent platform sedimentation remained characteristic of this area, which is part of Gondwana. Paleomagnetic data support this statement. Oceanic crust and thus any indications of the Tethys as a structural unit are absent in this area for that period of time. Its existence is only demonstrated in faunal provinces in shallow-marine facies. From the Infra-Cambrian to the Late Triassic the northern part of the area was open sea. During the Triassic, uplifting processes combined with deep lateritization and subsequent transgression initiated a basic change in the geodynamic regime. From this time on the ingressions into Iran proceeded from the south. At this time differentiation of facies began within small areas. Continental influences in the Jurassic sediments show that an elevated area was formed in Iran. At the same time ophiolite-radiolarite zones occurred, probably along long-lived geosutures. These zones are interpreted to be the result of processes breaking up the craton. Probably, the ingressions started from deep-sea furrows where ophiolite concentrations are found. The ascension of the ophiolitic material to the surface occurred along lines where gently dipping subduction of crust under crust took place. During this process it came to considerable crustal shortening. It is possible that the change in the tectonic regime during the Late Triassic coincided with the collision of the Arabia-Iran and Eurasia plates. The boundary between the Arabia-Iran and Eurasia plates is, however, not to be found in the area of the Persian Gulf and the Zagros mountain ranges, but is assumed to be north of the Elburz Mountains.
Résumé Chacune des unités tectoniques de l'Iran font l'objet d'un exposé concernant leur développement du point de vue de leur facies et de leur structure. Le facies et la paléogéographie indiquent que, de l'Infracambrien au Trias, tout le territoire compris entre le Golf persique et la chaîne de l'Elbours a eu un développement unitaire. Une sedimentation de plateforme cohérente, à facies de shell, caractérise cette région pendant toute cette période. C'est une partie du Gondwana. Des données paléomagnétiques appuient cette affirmation. Toute croûte océanique et, de ce fait toute indice d'une Téthys en temps qu'unité structurale, sont absent dans cette région à ce moment. Une mer ouverte s'y étend au nord de l'Infracambrien jusqu'au Trias supérieur. Au Trias, un soulèvement, auquel est liée une forte latéritisation, et la trangression qui lui est liée, entraînent un changement radical du régime géodynamique. A partir de ce moment, des ingressions se produisent en Iran à partir du sud introduisant des différences de facies. Des sédiments montrant une influence continentale montrent qu'au Jurassique un fort soulèvement s'est produit en Iran. En même temps, vraisemblablement suivant une géosuture depuis longtemps active, apparurent des zones ophiolothiques à radiolarites, qui indiquent une rupture intracratonique. Les ingressions émanent vraisemblablement d'un sillon océanique profond dans lequel sont également concentrées les ophiolithes. La montée du matériau ophiolithique à la surface s'en suivit le long de lignes suivant lesquelles se sont produits dessous-charriages intracrustaux, d'où sont résultés de notables racourcissements de la crôute. Il est possible que cette rupture du régime tectonique coïncide, au Trias supérieur, avec la collision des plaques de l'Arabie Iran et de l'Ewrasie. La limite entre l'Arabie-Iran et l'Eurasie ne se trouve donc pas dans la région du Golfe persique et des chaînes du Zagros, mais doit être recherchée au nord de la Chaîne de l'Elbours.
This paper discusses the effect of berm width and elevation of composite slope on irregular wave run-up. Based on the data obtained from model tests, the formula and distribution of irregular wave run-up on composite slope are derived. The changing of wind speed, width and elevation of the berm are considered comprehensively. The wave run-up with various exceedance probability can be es-timated utilizing the distribution curves of irregular wave run-up. 相似文献
Taking the example of Burush, N Darfur, Sudan, the authors analyse the role of migration as a survival strategy in the desertification-stricken Sahelian zone. It is being argued that the rual-rual migration plays a greater role than the rual-urban migration among the Berti ethnic group of northern Darfur. Their high mobility within their own area is part of their traditional economic pattern for coping with aridity and high rainfall variability 相似文献