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11.
Turkey was struck by two major events on 17 August and 12 November 1999, named Izmit (M w = 7.4) and Düzce (M w = 7.2) earthquakes, respectively. Rubble mound breakwaters in Izmit Bay experienced little damage, as forecasted by the new risk assessment model in which tsunami occurrence risk was included in the damage estimations. In order to determine the occurrence probability of structural damage under design conditions, including the environmental loading parameters of tsunami and storm waves, tidal range and storm surge, the Conditional Expections Monte Carlo simulation was applied in the risk assessment model developed in this study for the Esenköy Fishery Harbour, Turkey. A tsunami was not the key design parameter when compared to storm waves for the main breakwater of the harbour, however, in places with great seismic activity, the tsunami risk should be important depending on the occurrence probability and magnitude of the tsunami. 相似文献
12.
The devastating 1999 Marmara and Düzce earthquakes led to a significant increase in the earthquake studies in Turkey in geological,
engineering and financial aspects. Extreme Value Theory (EVT) has a range of applications from stock market changes to natural
disasters like floods and hurricanes. Here EVT is fitted to the ordinary and earthquake reinsurance claims of Turkey. 相似文献
13.
库车坳陷位于塔里木盆地北部,北缘是南天山山前断裂带,南缘是塔北隆起,呈NEE向展布,东西长250km,南北宽20-60km,面积约21170km^2。下侏罗统自下而上发育阿合组、阳霞组。对吐格尔明、克孜勒努尔、库车河剖面及依南2井岩芯观察发现,阿合组和阳霞组按其岩性特征均可以划分为5个岩性段,各个岩性段在全具有对比性。还可分出4类和17个亚类岩相。阿合组细砂岩以上的粗碎屑岩含量为80%以上;阳霞组细砂岩以上的碎屑岩含量为50%-60%。砂岩厚度占总地层厚度的50%-60%以上,是油气勘探的重要目的层系。以吐格尔明剖面为代表的依南2井以东地区的阿合组和阳霞组岩矿特征基本相似,以克孜勒努尔地区为代表的依南2井以西地区有较大差异,即阳霞组长石含量几乎为零。两区共同点是以岩屑砂岩为主,成分成熟度低,结构成熟度中等,岩屑含量较高。从岩性组合、沉积构造、微观岩石成分、结构和砂体形态等方面的综合分析认为,辫状三角洲沉积体系是该区阿合组和阳霞组的主要沉积体系。阿合组砂体纵向上以多个辫状三角洲平原上的辫状分流河道砂岩加积复合为主,横向上指状镶嵌叠置呈东西向展布。阳霞组第3岩性段砂体纵向上以多个辫状三角洲前缘上的水下辫状分流河道砂岩加积复合为主,横向上指状镶嵌叠置也呈东西向展布。第2、4、5岩性段砂体以河道滞流砂岩侧砂为主,横向叠瓦状叠置呈东西向展布。 相似文献
14.
An earthquake of magnitude 7.2 on the Richter scale occurred on 12 November 1999 in the Düzce-Bolu region of Turkey. The region was also hit approximately 3 months before during the devastating Kocaeli earthquake of 17 August 1999. Besides high casualties and damage to various engineering structures and buildings, slope and embankment failures on the highway and the country roads occurred. In this study, the authors are concerned with the back-analysis of an embankment failure that occurred on the four lanes E-5 highway connecting Ankara to Gstanbul at Bakacak in the Bolu Province during the 1999 Düzce earthquake. Both pseudo-dynamic and dynamic limiting equilibrium methods are used to back analyse the conditions for the initiation of failure and also displacement responses of the embankment during the earthquake shaking. After having given a brief summary of the investigations on the post-failure state, the geology and geotechnical characteristics of the site, and the dynamic limiting equilibrium method developed and used for analyses are described. The results of the back-analysis based on a pseudo-dynamic approach, revealed that the maximum ground acceleration to initiate the failure of the embankment was probably about 0.125 g. On the other hand, the application of a method for computing the displacement and velocity responses of the failed embankment showed that the failure was possible when the embankment was subjected to ground accelerations similar to that recorded at the Düzce station. In addition, the computations also revealed that the time history of accelerations could be very important for the failure of slopes and embankments. 相似文献
15.
Annibale Mottana Takatoshi Murata Ziyu Wu Augusto Marcelli Eleonora Paris 《Physics and Chemistry of Minerals》1997,24(7):500-509
X-ray absorption Na K-edge spectra have been recorded on synthetic endmember jadeite and on a series of natural Ca-Na pyroxenes
compositionally straddling the Jd-Di join. The C2/c members of the series are systematically different from the P2/n members. Differences can be interpreted and explained by comparing the experimental spectra with theoretical spectra. These
have been calculated by the multiple-scattering formalism from the atomic positional parameters determined by single-crystal
X-ray diffraction structure refinement on the same samples. In the full multiple scattering region of the spectra (1075 to
1090 eV) C-pyroxenes exhibit three features which reflect the 6-2 configuration of the O back-scattering atoms around the Na absorber
located at the center of the cluster (site M2 of the jadeite structure). P-pyroxenes show more complicated spectra in which at least four (possibly five) features can be recognized; they reflect the
two types of configuration (6-2 and 4-2-2) of O around Na in the two independent M2 and M21 eight-fold coordinated sites of the omphacite structure. A weak, sometimes poorly resolved peak at 1079 eV is diagnostic
and discriminates C- from P-pyroxenes. The Garnet Ridge C2/c impure jadeite exhibits a spectrum which is intermediate between those of jadeite and omphacite. The Hedin-Lundqvist potential
proves best for these insulating materials and allows multiple-scattering calculations agreeing well with experiments.
Received: July 11, 1996/Revised, accepted: October 21, 1996 相似文献
16.
17.
Karolina Kośmińska Frank S. Spear Jarosław Majka Karol Faehnrich Maciej Manecki Karsten Piepjohn Winfried K. Dallmann 《Journal of Metamorphic Geology》2020,38(5):471-493
Quartz-in-garnet inclusion barometry integrated with trace element thermometry and calculated phase relations is applied to mylonitized schists of the Pinkie unit cropping out on the island of Prins Karls Forland, western part of the Svalbard Archipelago. This approach combines conventional and novel techniques and allows deciphering of the pressure–temperature (P–T) evolution of mylonitic rocks, for which the P–T conditions could not have been easily deciphered using traditional methods. The results obtained suggest that rocks of the Pinkie unit were metamorphosed under amphibolite facies conditions at 8–10 kbar and 560–630°C and mylonitized at ~500 to 550°C and 9–11 kbar. The P–T results are coupled with in-situ Th–U-total Pb monazite dating, which records amphibolite facies metamorphism at c. 359–355 Ma. This is the very first evidence of late Devonian–early Carboniferous metamorphism in Svalbard and it implies that the Ellesmerian Orogeny on Svalbard was associated with metamorphism up to amphibolite facies conditions. Thus, it can be concluded that the Ellesmerian collision between the Franklinian margin of Laurentia and Pearya and Svalbard caused not only commonly accepted brittle deformation and weak greenschist facies metamorphism, but also a burial and deformation of rock complexes at much greater depths at elevated temperatures. 相似文献
18.
Astronomy Letters - We present LTE analysis of high resolution optical spectra for the B-type abundance standard candidate HD 35039 (HR 1765, 22 Ori) with an ambigous binary nature. The spectra... 相似文献
19.
20.
Olivier Moine Pierre Antoine Sylvie Coutard Gilles Guérin Christine Hatté Clément Paris Ségolène Saulnier-Copard 《第四纪科学杂志》2021,36(8):1322-1340
The Amiens-Renancourt 1 site recently yielded one of the most important Upper Palaeolithic human occupations of northern France by the number of flint artefacts and especially by the presence of Venus figurines. All the material comes from a single archaeological layer located in a tundra gley bracketed by loess units. A multi-proxy study combining a detailed stratigraphy, luminescence and radiocarbon datings and high-resolution (5 cm per sample) grain size and molluscan analyses was therefore carried out to reconstruct and date the associated environmental changes and to determine the exact context of the human occupation. The chronological frame thus established supports the correlations of the archaeology-bearing tundra gley and of an underlying arctic brown soil with Greenland interstadials GI-4 and GI-3. Composition changes in the molluscan population enabled the identification of transitional and optimum phases and sub-phases within these two pedogenetic horizons. A conceptual correlation model linking molluscan phases with millennial-scale variations of Greenland ice-core and Sieben Hengste speleothem climate records is proposed. The Human occupation appears contemporaneous to the end of the stadial–interstadial transition of GI-3. Synchronous in Amiens-Renancourt 1 and Nussloch, subsequent micro-gleys may also result from a regional/global forcing. Such a level of detail is unprecedented in a loess sequence. 相似文献