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391.
YANG Baoliang QIU Longwei YANG Yongqiang Kouassi Louis KRA DONG Daotao Danish KHAN 《《地质学报》英文版》2023,97(2):526-547
Coarse-grained subaqueous fans are vital oil and gas exploration targets in the Bohai Bay basin, China. The insufficient understanding of their sedimentary processes, depositional patterns, and controlling factors restricts efficient exploration and development. Coarse-grained subaqueous fans in the Yong′an area, Dongying Depression, are investigated in this study. These fans include nearshore subaqueous fans, and sublacustrine fans, and their sedimentary processes, depositional patterns and distribution characteristics are mainly controlled by tectonic activity and paleogeomorphology. Nearshore subaqueous fans developed near the boundary fault during the early–middle deposition stage due to strong tectonic activity and large topographic subsidence. Early sublacustrine fans developed at the front of the nearshore subaqueous fans in the area where the topography changed from gentle to steep along the source direction. While the topography was gentle, sublacustrine fans did not develop. During the late weak tectonic activity stage, late sublacustrine fans developed with multiple stages superimposed. Frequent fault activity and related earthquakes steepened the basin margin, and the boundary fault slopes were 25.9°–34°. During the early–middle deposition stage, hyperpycnal flows triggered by outburst floods developed. During the late deposition stage, with weak tectonic activity, seasonal floods triggered hyperpycnal flows, and hybrid event beds developed distally. 相似文献
392.
Mathematical Geosciences - Machine-learning-based proxy models are often used to replace many of the flow simulations required in optimizations of subsurface flow processes. Because the optimizer... 相似文献
393.
394.
395.
A red rain phenomenon occurred in Kerala, India starting from 25th July 2001, in which the rainwater appeared coloured in
various localized places that are spread over a few hundred kilometers in Kerala. Maximum cases were reported during the first
10 days and isolated cases were found to occur for about 2 months. The striking red colouration of the rainwater was found
to be due to the suspension of microscopic red particles having the appearance of biological cells. These particles have no
similarity with usual desert dust. An estimated minimum quantity of 50,000 kg of red particles has fallen from the sky through
red rain. An analysis of this strange phenomenon further shows that the conventional atmospheric transport processes like
dust storms etc. cannot explain this phenomenon. The electron microscopic study of the red particles shows fine cell structure
indicating their biological cell like nature. EDAX analysis shows that the major elements present in these cell like particles
are carbon and oxygen. Strangely, a test for DNA using Ethidium Bromide dye fluorescence technique indicates absence of DNA
in these cells. In the context of a suspected link between a meteor airburst event and the red rain, the possibility for the
extraterrestrial origin of these particles from cometary fragments is discussed. 相似文献
396.
Louis Grinda 《Pure and Applied Geophysics》1973,103(1):316-331
Résumé Au colloque de Paris (1970) sur les Microseismes (MS) l'auteur a formulé les principes d'une théorie qui montre le rôle important, dans la génération des MS, joué par les houles croisées et donc par les variations de la direction du vent sur la mer, l'effect sélectif de la réflexion de la houle par une côte, la réfraction de la houle, le filtrage des houles arrivant à la côte par effet des petits fonds, la vitesse de propagation de la houle, généralement plus grande que celle des cyclones, le diagramme de rayonnement des sources, et par conséquent par la bathymétrie comme par la morphologie des côtes proches de la zone de génération.Des cas concrets de MS bien étudiés en fonction des circonstances météorologiques et océanographiques illustrent et justifient les principes originaux de cette théorie, en particulier ceux qui font l'objet des travaux dont les titres indiqués dans la bibliographie, concernent les MS classiques de la bande de périodes de 2 à 18 secondes.
Summary During the Symposium on microseisms of Paris (Sept. 1970), the author has formulated the principles of a theory which shows the leading part taken in the generation of microseisms by: Swells more or less crossed and therefore by changes in the direction of the wind; Selective effects of the reflection of the sea waves; The filtering of the components of the swell when it arrives on small depths; The speed of the swell generally faster than the cyclone; The diagram of radiance sources, and, consequently, by the bathymetry and the morphology of the coasts.Three concrete cases illustrate and justify the theory. They are well described in the papers quoted in References.相似文献
397.
The influence of internal tides on phytoplankton photosynthetic response to light was studied in the Lower St. Lawrence Estuary. Photosynthesis at saturating light intensity responded to variations in the vertical density gradient, which were linked to the internal tides. The photosynthetic response was lag-correlated to the vertical water stratification. This suggests that the link between photosynthesis and the internal tides may have resulted from phytoplankton light adaptation. 相似文献
398.
The subject is reviewed, notwithstanding the existence of a number of disagreeing and/or controversial results found in the literature. First, a brief critical reexamination of the methodology is presented. Second, it is attempted to put the results, or partial conclusions by different authors, using different methods and referring to different geographical regions, into a working scheme. This is done by investigating, as far as possible, the relationships between the electrical conductivity information and other types of geophysical and geological information for each geographical area investigated. It appears almost impossible to draw general conclusions that hold for the entire Earth. Conclusions are given for those areas with some very well-defined geomorphological characters. Unfortunately, the available investigations still appear to give a poor coverage of several types of geographic areas with specific tectonic characteristics, and certainly the scientific coverage by electromagnetic methods of investigation cannot be compared with those available today from seismological methods. Investigating the electrical conductivity structure of the lower crust certainly opens relevant heuristic possibilities, but there appears to be a great need both for a refinement in the basic methodology, and for a better coverage of the investigated areas. 相似文献
399.
Louis H. Motz 《Ground water》1982,20(2):170-178
400.
An attempt is made, for an anticyclonic stable situation in the atmospheric boundary layer during November 1978, to estimate the dissipation length. The turbulent dissipation and the turbulent kinetic energy, as measured on a 100 m high mast, exhibit large variability, due to the sporadic turbulent structure of the stable layer, and associated variability of the Richardson number. A comparison with different parameterizations of the turbulent dissipation rate allows a validation of these parameterizations. 相似文献