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郯庐断裂带中段全新世活断层的特征滑动行为与特征地震 总被引：16，自引：0，他引：16
郯庐断裂带中段全新世活断层由３个独立的破裂段组成。从各破裂段的运动性质、位移分布看，断层的运动属特征地震型滑动。地震活动以强震活动为主，强震具有周期性原地重复发生的特点，且其强度基本相同；中强地震缺失或很少发生；ｂ值在高震级范围内具低ｂ值的非线性关系。这些特点正是特征地震的典型表现．根据郯庐断裂带中段活断层全新世以来的活动特点看，未来该区仍然以特征地震方式活动．按郯庐带的强震复发间隔和各段的最新一次活动时代推算，未来一段时期内新沂－宿迁段复发大震的可能性较大，安丘段次之，莒县－郯城段复发大震的可能性则很小。 相似文献
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在考虑地震失稳的滑动－弱化特征后，研究了估计大地震重复间隔的问题，建议了一种计算大地震重复间隔的方法，给出了计算复发间隔的公式。同时，应用这个方法计算了海原断裂带、华山山前断裂带、贺兰山东麓断裂带和小江西支断裂带的８级大震复发间隔，它们分别为３４６６年、２０４３年、２６８８年和９７５年。这些数值与古地震研究给出的实际古地震复发间隔甚为一致，说明建议的计算方法可以应用于活动断裂地震复发时间和地震危险性的估计。 相似文献
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汶川MS8.0地震发生在青藏高原东缘著名的龙门山断裂带上,造成了从映秀、北川至南坝长约240km的同震地表破裂带．然而目前关于龙门山断裂带的大震复发特征研究较少．通过地震地质科学考察和断层断错地貌的差分GPS测量,发现第一级河流阶地、河床和河漫滩上的垂直断距大致相当,均代表汶川地震的位错,而第二级河流阶地上的累计位移大致是最新地震垂直位移的2倍．利用断错地貌、地震矩率和滑动速率3种方法,分别估算了龙门山断裂带大地震的复发间隔．结果表明:龙门山断裂带中北段可能发生与汶川大地震相当的地震,大震复发符合特征地震模型;大震复发间隔为3000——6000a．该结果可为龙门山断裂带的大震预测和地震危险性评价等研究提供重要的定量数据． 相似文献
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中国大陆原地复发强震的基本特征及其预测 总被引：7，自引：3，他引：7
在印度板块与欧亚块相碰撞形成的喜马拉雅弧板块边界力作用下，中国大陆有自己独特的现代构造运动和地震活动基本格架。格架是两组近似于对数螺线的现代构造滑移线，即最大剪切应力和剪切应变集中释放的区，带。在这种格架控制下，强震和大震在原地或基本在原地重复发生是中国大陆地震活动的重要特征。本文还提出了ｉ－ｆ－ｊ复发轮回模式和估计当前轮回强震复发时间的概率分布以及计算未来强震复发概率分式。为中，长期预测原地复发 相似文献
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汶川M_S8.0级地震发震构造大震复发间隔估算 总被引：1，自引：0，他引：1
汶川Ms8．0级地震发生在青藏高原东缘著名的龙门山断裂带上,造成了中央断裂和前山断裂共约330kin的地震地表破裂带。初步研究表明,龙门山断裂带上大震复发可能属特征地震模式。结合龙门山断裂带的地震地质情况和汶川地震地表破裂带的基本参数综合分析,本文从地质学、地震学和GPS数据分析三个方面评估了龙门山断裂带的大震复发周期。结果表明,上述三种方法获得的龙门山断裂带Ms8．0级地震的复发间隔分别为：3185a、170（02264a和4310a,平均为3000a左右：Ms7．5级地震的平均复发间隔为1000a左右;Ms7．0级地震的平均复发间隔为500a左右。这些结果与其他学者的研究结果相比,相差不多,基本反映了龙门山断裂带的地震能量水平和累积速度。 相似文献
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通过重新编制活动断层定量参数数据库,利用中国大陆活动断裂定量资料评估了中国大陆活动断裂(段)的大震复发间隔,给出了青藏、新疆、华北3个构造区的大震复发间隔分布特征。研究结果表明,青藏高原活动断裂M7.5级以上大震复发间隔远小于华北和新疆。青藏高原从几100a到2000a,而华北和新疆则从2000a到5000a。大震复发间隔与断层滑动速率成反比,边界断裂的大震复发间隔通常比块体内部断裂短,比例关系大体为1:1.5—2.0。大震复发间隔与断裂性质相关,走滑断层的复发间隔小于逆走滑断层,逆走滑断层小于逆断层,比例关系大体为1:1.5—2.5。现有的定量数据汇编成果和大震复发间隔估计以及统计结果,既可作为地震危险性分析的重要参数,又可作为构造类比研究的参考信息。 相似文献
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丽江大震前长—中—短—临地震学异常的演化过程 总被引：4，自引：6，他引：4
本通过丽江大震前地震学各项异常的动态追踪，研究了长－中－短－临异常伴随大震孕育、发生的演化过程，结果表明：在强震的缺震、强震的重复、中强震密集、诱发地震、相关地震等多项长期异常的背景上，出现了中小地震活跃、调制小震频繁、复发周期降低、震源深度加深和震级差增大、地震序列ｈ值下降等同步的中期异常，而１９９５年中小地震活跃后的平静、低复发周期的回升、震源深度为２５公里和震级差在１．０－１．１级的地震次 相似文献
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断层滑动速率,地震重复时间和平均应力降 总被引：5，自引：0，他引：5
本文综述了国内外大地震复发间隔研究的现状，系统整理了中国大陆活断层滑运速率，已发现的古地震遗迹及古地震复发间隔，结果表明，在滑动速率较在的活断层发现的古地震复发间隔较短，Ｋａｎａｍｏｒｉ和Ａｌｌｅ（１９８５）研究了具有大范围重复时间（２０年到几千年）的板内大地震的震源参数，发现复发间隔较长的大地震具有较高的平均应力降，我们在实验室内研究了应变速率不同时固体围压三轴压缩下完整花岗岩破裂后的粘滑现象。 相似文献
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—We classified tsunamigenic earthquakes in subduction zones into three types earth quakes at the plate interface (typical interplate events), earthquakes at the outer rise, within the subducting slab or overlying crust (intraplate events), and "tsunami earthquakes" that generate considerably larger tsunamis than expected from seismic waves. The depth range of a typical interplate earthquake source is 10–40km, controlled by temperature and other geological parameters. The slip distribution varies both with depth and along-strike. Recent examples show very different temporal change of slip distribution in the Aleutians and the Japan trench. The tsunamigenic coseismic slip of the 1957 Aleutian earthquake was concentrated on an asperity located in the western half of an aftershock zone 1200km long. This asperity ruptured again in the 1986 Andreanof Islands and 1996 Delarof Islands earthquakes. By contrast, the source of the 1994 Sanriku-oki earthquake corresponds to the low slip region of the previous interplate event, the 1968 Tokachi-oki earthquake. Tsunamis from intraplate earthquakes within the subducting slab can be at least as large as those from interplate earthquakes; tsunami hazard assessments must include such events. Similarity in macroseismic data from two southern Kuril earthquakes illustrates difficulty in distinguishing interplate and slab events on the basis of historical data such as felt reports and tsunami heights. Most moment release of tsunami earthquakes occurs in a narrow region near the trench, and the concentrated slip is responsible for the large tsunami. Numerical modeling of the 1996 Peru earthquake confirms this model, which has been proposed for other tsunami earthquakes, including 1896 Sanriku, 1946 Aleutian and 1992 Nicaragua. 相似文献
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Introduction For a long time, the seismologists have paid great attentions to the research on the spatio- temporal distribution of earthquake intensity, which provide us with significant information for the researches on crustal stress variation, tectonic activity and earthquake risk prediction in a certain spatio-temporal region. The existing results have shown consistently that the intensity of earth- quakes is characterized by non-stability, non-linearity in temporal domain and non-uniformi… 相似文献
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— We construct a viscoelastic FEM model with 3-D configuration of the subducting Philippine Sea plate in Southwest Japan to simulate recent 300-year kinematic earthquake cycles along the Nankai-Suruga-Sagami trough, based on the kinematic earthquake cycle model. This 300-year simulation contains a series of three great interplate earthquakes. The inclusion of viscoelasticity produces characteristic velocity field during earthquake cycles regardless of the assumed constant plate coupling throughout the interseismic period. Just after the occurrence of interplate earthquakes, the viscoelastic relaxation creates the seaward motion in the inland region. In the middle period, the seaward motion gradually decreases, and the resultant velocity field is similar to the elastic one. Later, just before the next interplate earthquake, displacements due to the interplate coupling in the viscoelastic material are distributed more broadly in the forearc region than in the purely elastic one, since the viscoelastic relaxation due to the previous earthquake mostly disappears. The effects of such interplate earthquake cycles on five major inland faults in southwest Japan, where large intraplate earthquakes occurred during this period, are quantitatively evaluated using the Coulomb failure function (CFF). The calculated change in CFF successfully predicts the occurrence of the 1995 Kobe earthquake (M～7). The occurrence of other inland earthquakes, however, cannot be explained by the calculated changes in CFF, and especially the 1891 Nobi earthquake (M～8), the largest inland earthquake in Japan, which occurred at the time close to the local minimum of CFF. This implies that further improvements are necessary for our FEM modeling, such as the modeling of steady east-west compressive force and stress interactions between the inland faults. 相似文献
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甘改—玉树断裂带的近代地震与未来地震趋势估计 总被引：3，自引：1，他引：3
通过对甘改－玉树断裂带上近代地震的震级，震中位置和地震地表破裂的空间展布特征的研究，采用Ｎｉｓｈｅｎｋｏ和Ｂｕｌａｎｄ发展的“特征地震复发时间通用分布”概率模型，即“ＮＢ”模型，对甘孜玉树断裂带各段落未来５０ａ内强震趋势进行了估计。 相似文献
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Mario Octavio Cotilla Rodriguez 《Journal of Seismology》1998,2(4):323-335
The seismicity of Cuba is briefly presented together with a few fundamental neotectonic elements of the adjacent Caribbean region. The Cuban seismicity catalogue has been extended back to 1528 and it shows that the largest earthquakes occurred in 1766 and 1852 (I = IX MSK). Two types of seismicity (intraplate and interplate) can be distinguished in Cuba. Western and Eastern Seismotectonic Units correspond to intraplate type and the Southeastern Seismotectonic Unit to interplate type. Western Cuba is characterized by a low frequency of earthquake occurrence. Distribution of epicenters is not regular and the most important events mainly concentrate along two regional active fault system (Nortecubana and Surcubana). Due to the lack of seismic stations in this region, the characterization of seismicity is frequently done on the grounds of historical data available from 1693. The main seismogenic source for Cuba is the Bartlett-Cayman fault system, but inland there are other active structures. Some issues about historical and present day Cuban seismological research are also showed. 相似文献