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林甸(Ms=5.1)地震发生于2005年7月25日,震中靠近大庆油田.该地震对大庆油田造成一定的破坏和损失,为原有的大庆油田地震损失评估与应急反应系统提供了验证实例.按照林甸地震的参数设定地震、评估震害,对比评估的结果和地面调查结果,差异较大.确定差异产生的主要原因是:(1)系统选取的烈度衰减关系与这次地震的烈度衰减关系不符;(2)系统空间数据存储方式的简化.通过平移等震线至宏观震中、同倍率放大等震线和更改计算单元等方法,深入分析系统评估结果和地面调查结果间的差异,指出改善评估精度、进一步发展完善此类系统的关键点. 相似文献
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本文讨论了断层破裂烈度衰减模型,指出由它给出的烈度等震线的长轴向不很符合实际的等震线;在地震危险性分析中,该模型会高估高烈度的危险性。本文建议一个用等效破裂长度代替破裂长度的改进的断层破裂烈度衰减模型。统计数据和唐山地震的资料证实它能较好地拟合实际的等震线,从而改善地震危险性分析的结果。等效破裂长度的经验公式可表示为LnSe=a+bM-cl~3。它可以直接由历史地震等震线的资料统计得到。最后以河南小浪底水库坝址的地震危险性分析作为应用此烈度衰减模型的一个实例。 相似文献
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本文讨论在地震危险性分析中目前使用广泛的地震烈度衰减模型,即Cornell建立的点源模型和洪华生(A.H-S.Ang)等建立的断层-破裂模型。与实际烈度资料的比较表明,在等震线狭长的区域,点源模型有系统偏差,通常这种偏差不算严重。为了克服上述偏差,断层-破裂模型引进了破裂长度的概念,但其衰减与实际资料出入较大。与实际地震等震线的比较和计算表明,对大地震沿断层或等震线长轴方向,断层破裂模型总是高估高烈度区而低估低烈度区。此外,本文分析了断层破裂模型产生系统偏差的原因,讨论了点椭圆模型的合理性,并用地震危险性分析实例做了说明。 相似文献
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我国目前使用最多的烈度衰减模型为椭圆衰减模型,这种烈度衰减模型在对中强地震烈度等震线形状的描述比较接近,而对于断层长度较大的强震高烈度区的描述存在较大的偏差.而大震真实的烈度等震线形状在近场接近于“跑道”形状,而在中远场又趋近于“椭圆”.如何建立一种能够同时近似这两种模型的烈度衰减模型是一个亟待解决的问题.因此,本文提出了一种基于等震线面积和长轴半径的烈度衰减关系的建立方法.并搜集了我国38次震级(Ms)大于6级的地震,对本文提出的衰减关系建立方法进行了验证.结果表明,基于等震线面积和长轴半径的衰减关系能够很好地拟合实际地震等震线的形状. 相似文献
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1605年7月13 日(明万历三十三年五月二十八日)在海南琼山发生了一次71/2级大地震,震中烈度为Ⅹ度.地震在琼州海峡两岸,特别是在海南岛的北部地区造成了严重的破坏.经前人的研究,该震已有极震区不同方向的3个等震线,一是Ⅹ和Ⅸ度等震线为近东西向(1995年中国强震目录);一是陈恩民(1979)给出的Ⅺ、Ⅹ、Ⅸ度的等震线呈近东西和北北西相交的丁字形分布;另一个是丁原章给出北北西向的极震区.关于1605年地震的上述3个等震线,哪一个更能反映该地震震源破裂方向仍存在争论. 相似文献
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云南洱海现代沉积研究 总被引:1,自引:1,他引:0
洱海是位于云南省境内较大的但相对较浅的断陷湖泊(水深小于20m)。根据1990-1993年对该湖现代沉积的研究,结果表明,湖泊沉积物主要是来自西部相对高2000m以上的山地,东部为低矮石灰岩山地,物源较少,南北两条入湖河流亦是重要的物源供应区。湖区沉积物主要是由粉砂质粘土组成,来自山地的粗碎屑物质则大量的堆积于此地,三角洲、扇三角洲及滨湖地带,沉积速度在过去13000年中平均为0.2cma^-1, 相似文献
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The role of aerial algae in the formation of the landscape of the Yunnan Stone Forest,Yunnan Province, China 总被引:1,自引:0,他引:1
TIAN Youping ZHANG Jie SONG Linhua & BAO Haosheng . Institute of Geographic Sciences Natural Resources Research Chinese Academy of Sciences Beijing China . Department of Geography Nanjing University Nanjing China . School of Earth Sciences Resources China University of Geosciences Beijing China 《中国科学D辑(英文版)》2004,47(9)
~~The role of aerial algae in the formation of the landscape of the Yunnan Stone Forest,Yunnan Province, China~~ 相似文献
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Lithospheric Geothermal Structure in Yunnan, China 总被引:2,自引:0,他引:2
Zhou Zhenheng Xiang Caiying and Deng WanmingSeismological Bureau of Yunnan Province Kunming China Institute of Geology Chinese Academy of Sciences Beijing China 《中国地震研究》1998,(1)
In this paper,the characteristics of the lateral variations of the deep heat flow and Hthospheric geotemperature distribution in Yunnan have been studied,and the lithospheric geothermal structure has been divided into three types,i.e.the geothermal structure in the typical modern tectonically active region,transitional geological region and stable geological region.Finally,the relationship between the geotherm and seismicitv has been discussed. 相似文献
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GAO Yuxin XU Chong TIAN Yingying MA Siyuan SHEN Lingling LU Yongkun RAN Hongliu 《中国地震研究》2020,34(1):50-63
Using Google Earth software as a platform, this study has established an integrated database of both old and new landslides in Baoshan City, Yunnan Province, China, and analyzed their development characteristics together with distribution rules, respectively. Based on the results, a total of 2 427 landslides occurred in the study area, including 2 144 new landslides and 283 old landslides, with a total area of about 104.8 km2. The new landslides are mostly in small-scales with an area less than 10 000 m2, while the area of individual old landslide is mostly larger than 10 000 m2. By analyzing the relationship between the two types of landslides and eight impact factors (i.e., elevation, slope angle, slope aspect, slope position, lithology, fault, regional Peak Ground Acceleration (PGA), and average annual rainfall), the different individual influencing factors, distribution regularities and mechanisms of the two types of landslides are revealed. In detail, the main influencing factors of new landslides are elevation, slope angle, slope aspect, slope position, lithology, regional PGA and average annual rainfall, while the influencing factors of old landslides are mainly elevation, slope angle, and lithology. This study provides basic data and support for landslide assessment and further disaster reduction in Baoshan City. Besides, it also provides new constraints in deeply understanding the effect of different topographic and geological conditions, historical earthquakes, rainfall and other factors on the occurrence mechanisms of both new landslides and old landslides. 相似文献
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分析S波土层/基岩和脉动水平/垂直的频谱比,分别得出了位于丽江峡谷南段、中段和北段的丽宾、白沙和玉龙3个台站的场地放大.使用的资料是1996年2月3日云南丽江MS=7.0地震余震的数字记录.在1~4 Hz频率范围内,丽宾台S波东西分量土层/基岩频谱比最大,达4.5;丽宾台脉动土层北南/垂直频谱比接近1,东西/垂直频谱比约为4.5,且与上述土层/基岩频谱比相同.表明脉动的垂直和北南分量未被土层放大,单台Nakamura法可用.用此法进而求出了白沙和玉龙的脉动频谱比,它们具有同丽宾脉动频谱比类似的特征.在上述频率范围内,两台的北南/垂直频谱比接近1,而东西/垂直频谱比白沙台约为6,玉龙台约为4.5.在丽江峡谷有横越峡谷的方向性场地响应特征. 相似文献
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Crustal seismic anisotropy in Yunnan, Southwestern China 总被引:5,自引:0,他引:5
Using seismic data recorded by Yunnan Telemetry Seismic Network from January 1, 2000, to May 31, 2005, the polarization directions
of fast shear waves are obtained at 15 seismic stations by SAM technique, which is a systematic analysis method on shear-wave
splitting. The results show that predominant directions of polarizations of fast shear waves at most stations are mainly nearly
in the N–S or NNW directions in Yunnan. The predominant polarization directions of fast shear waves at stations located on
the active faults are consistent with the strike of active faults, directions of regional principal compressive strains from
GPS measurement, and directions of regional principal compressive stress. A few of the stations show that polarization patterns
of fast shear waves are more complicated or inconsistent with the strike of active faults and the directions of principal
GPS compressive strains; these stations are always located at the junction of several faults. We conclude that the predominant
polarization direction of fast shear waves indicates that the direction of the in situ maximum principal compressive stress
is controlled by multiple tectonic aspects, such as the regional stress field and faults. 相似文献
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