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51.
地震灾害快速评估的计算机方法和程序 总被引:4,自引:0,他引:4
文中介绍一种在微机上实现的地震灾害快速评估应用软件:DISEV,DISEV由地震输入系统,图形显示系统,灾害评估系统和数据输出系统等4部分组成,采用确定性的地震灾害评估方法,用C语言设计完成,DISEV操作简单,快速,对震后快速反应工作以及救灾工作有重要意义。 相似文献
52.
Yanmei Wu Peter D. Clift Jiabiao Li Shaoru Yin Yinxia Fang 《International Geology Review》2020,62(7-8):970-987
ABSTRACT We calculated the sedimentary budget of the Northwest Sub-basin (NWSB), South China Sea for different geological times based on interpretations of four multichannel seismic profiles across the basin with constraints from International Ocean Discovery Program (IODP) Expeditions 367 and 368 drilling results. Sedimentation was generally dominated by regional tectonic events and climate change, but complicated by local tectonic events and geographic position, which resulted in a specific sedimentary budget in the NWSB compared with other marginal basins and the Southwest Sub-basin. The sedimentation rate was relatively low following the opening of the NWSB but increased gradually during the Middle Miocene, corresponding to the uplift of the Tibetan Plateau and the Asian monsoon. It reached its peak in the Late Miocene, corresponding to uplift of the Dongsha Island region that caused intensive bypass of eroded sediments from the Baiyun Sag into the abyssal basin, and reduced again during the Pliocene because of sediment storage on the wide northern continental shelf area compared to the abyssal basin during a period of high-stand sea level. Increase in sedimentation during the Pleistocene suggests that continental erosion and sediment transport to the abyssal basin were enhanced by an intensified Asian summer monsoon and glacial-interglacial climate fluctuations. Since the opening of the NWSB, the primary sediment provenance has been from southern China, with minor contributions from the Red River, Hainan Island, as well as local uplifts on the continental shelf. 相似文献
53.
夏骥 《云南地理环境研究》2006,18(3):62-66
西部大开发战略的实施为西部地区的发展提供了历史性机遇.西部边疆五省区在西部经济发展中扮演着重要的角色,加快其发展对于西部大开发具有重要意义.西部边疆五省区具有显著的资源优势、区位优势和政策优势,经济发展的潜力巨大;同时,它们在人口、经济、生态环境等方面所面临的一系列共同的问题,又严重阻碍了其发展步伐.因此,如何抓住西部大开发的机遇,制订有效的对策和措施,扬长避短、进一步加快其发展,是西部边疆五省区应认真面对的问题. 相似文献
54.
Abstract We collected free-gas and in situ fluid samples up to a depth of 200.6 m from the Sagara oil field, central Japan (34°44'N, 138°15'E), during the Sagara Drilling Program (SDP) and measured the concentrations and stable carbon isotopic compositions of CH4 and C2 H6 in the samples. A combination of the CH4 /C2 H6 ratios with the carbon isotope ratios of methane indicates that the hydrocarbon gases are predominantly of thermogenic origin at all depths. The isotope signature of hydrocarbon gases of δ13 < δ13 suggests that these gases in the Sagara oil field are not generated by polymerization, but by the decomposition of organic materials. 相似文献
55.
56.
USGCRP土地覆被研究的最新动向 总被引:12,自引:1,他引:11
本文根据美国全球变化研究委员会提出的“美国全球变化研究计划”(USGCRP),概要介绍了土地覆被研究的目标、内容和设想。由于美国在这一领域研究中的领先地位,因此本文基本反映了国际上的最新趋势。 相似文献
57.
Middle Miocene to Pleistocene radiolarian biostratigraphy in the Northwest Pacific Ocean, ODP Leg 186 总被引:2,自引:0,他引:2
Abstract The Upper Cenozoic sedimentary sequences drilled at Sites 1150 and 1151, Ocean Drilling Program Leg 186, enabled establishment of radiolarian zonation and calibration of the age of bioevents in the forearc area of the northern Japan Islands. The sequences were divided into nine zones from the Pleistocene Botryostrobus aquilonaris Zone to the Upper Miocene Lipmanella redondoensis Zone at Site 1150, and 11 zones from the Pleistocene Stylatractus universus Zone to the Middle Miocene Dendrospyris? sakaii Zone at Site 1151. These zones correlate successfully with the studied sequences of many of deep‐sea cores in the Northwest Pacific Ocean and with some sections of onshore Japan. Of 67 important radiolarian bioevents recognized during the study, 29 Pleistocene to Upper Miocene events were directly tied to the geomagnetic polarity time scale through the well‐defined paleomagnetic polarity records, and 21 Upper Miocene events were calibrated based on the diatom biostratigraphy. Of these events, 24 geographically widespread events were selected to test synchroneity and usefulness as time‐horizons within the mid‐to‐high latitude of the Northwest Pacific, involving eight other offshore and onshore sections. Examination showed that most of the zonal boundary events are synchronous within the considered region, and that many diachronous events, most of which are eliminated from the zonal scheme, are unreliable events linked to rare and sporadic occurrences of the species. Radiolarian biostratigraphy of the studied cores clearly indicates three major hiatuses in the Middle Pleistocene, Late Miocene and late Middle Miocene. The latter two hiatuses can be correlated to two global oceanic hiatuses, NH6 and NH3, respectively. 相似文献
58.
59.
道路中线坐标计算程序 总被引:1,自引:0,他引:1
采用CASIO fx—4500P科学计算器编程,由道路设计参数和给定桩距计算路线转角、曲线测设元素、主点里程以及以道路中线上主点或任意点作起点的各中桩点(含全部主点)在国家坐标系中的坐标. 相似文献
60.
Development of northwest Pacific guyots: General results from Ocean Drilling Program legs 143 and 144 总被引:1,自引:0,他引:1
Peter Flood 《Island Arc》1999,8(1):92-98
Results of the Ocean Drilling Program legs 143 and 144, which investigated the nature and origin of seven guyots in the northwest Pacific Ocean, document a history of prolonged volcanism (128–84 Ma), followed by subsidence, accumulation of shallow-water carbonates, emersion following a sea-level fall, then continued subsidence, and drowning. Generally, the life span of a guyot is of the order of 5–20 million years. The stratigraphic sequence in each guyot consists of 3–10 m-thick, shoaling-upward cycles, which display a 100-Ka periodicity perhaps related to sea-level fluctuations. The drilling results indicate that the demise of the shallow-water carbonate platforms is related to either a temporal (110–100 Ma) event or paleolatitude location (0–10°S) involving nutrient-rich water not conducive to production of calcium carbonate by shallow-water organisms. Following emergence and erosion, re-submergence occurred during a rise of sea-level. However, the rate of sediment accumulation was unable to keep pace with the rate of sea-level rise and the guyots drowned. Subsidence continued as the lithospheric plate cooled. The majority of guyots are now at ~ 1500 m below sea-level. Plate movements over the past 100 million years have carried the guyots from ~ 14°S to their current location in the northwest Pacific. Guyots are flat-topped submerged volcanic islands capped by thick sequences of shallow-water carbonates. The flat-top morphology is constructional, not related to wave planation as originally thought and reported in most textbooks. 相似文献