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991.
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994.
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
995.
Chi-Yu King 《Pure and Applied Geophysics》1994,143(1-3):457-482
Slip events generated in a laboratory fault model consisting of a circulinear chain of eight spring-connected blocks of approximately equal weight elastically driven to slide on a frictional surface are studied. It is found that most of the input strain energy is released by a relatively few large events, which are approximately time predictable. A large event tends to roughen stress distribution along the fault, whereas the subsequent smaller events tend to smooth the stress distribution and prepare a condition of simultaneous criticality for the occurrence of the next large event. The frequency-size distribution resembles the Gutenberg-Richter relation for earthquakes, except for a falloff for the largest events due to the finite energy-storage capacity of the fault system. Slip distributions, in different events are commonly dissimilar. Stress drop, slip velocity, and rupture velocity all tend to increase with event size. Rupture-initiation locations are usually not close to the maximum-slip locations. 相似文献
996.
本文根据三角网统一平差和跨断层测量资料,利用位错理论的反演方法,计算了唐山和北京,怀来地区几条主要断层滑动速率和滑动方向,其结果与我们用有限元方法计算的断层应力场配套。并获得三点结果:(1)断层滑动速率大,则断层上庆力高,反之亦然;(2)断层滑动方向与断层应力场方向配套;(3)当跨断层短线大度年变化持续出现线笥关系时,断层浅部与深部滑动一致,而且断层浅部滑速率大,此却表示有发生地震的危险性。 相似文献
997.
In this paper, the major idea is: when seismic stress accumulates to a certain extent, a stick slip earthquake will occur
on the fault plane. The seismic stress before and after the stick slip earthquake occurrence are both stochastic variables.
According to this idea, the model of double bounds of stochastic stress is proposed, and also it is used to analyse the seismic
risk of Xian Shui River Fault Zone in the coming 30 years, the result is similar to what the Seismological Bureau of Sichuan
Province has predicted.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 477–483, 1993. 相似文献
998.
History and modes of Mesozoic accretion in Southeastern Russia 总被引:8,自引:1,他引:8
Abstract The history of Mesozoic accretion and growth of the Asia eastern margin, occupied by Southeastern Russia, includes five main events; two main tectonic regimes were responsible for the growth of the continent. In the Triassic-Jurassic, Early Cretaceous and Late Cretaceous-Paleogene, the subduction of the oceanic lithosphere resulted in the formation of wide accretionary wedges of the Mongol-Okhotsk, Khingan-Okhotsk and Eastern Sikhote-Alin active continental margins, respectively. These stages of the comparatively slow growth of the continent were broken by stages of rapid growth and drastic changes in the shape of the continent, since at these stages large terranes of various tectonic nature collided with active continental margins. At the end of the Early-Middle Jurassic, the Bureya terranes collided with the Mongol-Okhotsk active margin, and at the beginning of the Late Cretaceous there was collision of the Central and Southern Sikhote-Alin terranes with the Khingan-Okhotsk active margin.
Collision-related structural styles in all cases are indicative of oblique collision and great strike-slip motions along the main sutures. The peculiarities of the terrane's geological structure show that prior to collision with the Mongol-Okhotsk and Khingan-Okhotsk active margins, they had already accreted to Asia and then migrated along its margins along the strike-slip faults. The Bureya terranes were squeezed out of the compression zone between Siberia and North China. This compression zone originated after the Paleozoic oceans which divided these cratons had closed. The Khanka terranes and Mesozoic accretionary wedge terranes of the Sikhote-Alin shifted along the strike-slip faults subparallel to the Asia Pacific margin. Strike-slip motions resulted in duplication of the primary tectonic zonation. 相似文献
Collision-related structural styles in all cases are indicative of oblique collision and great strike-slip motions along the main sutures. The peculiarities of the terrane's geological structure show that prior to collision with the Mongol-Okhotsk and Khingan-Okhotsk active margins, they had already accreted to Asia and then migrated along its margins along the strike-slip faults. The Bureya terranes were squeezed out of the compression zone between Siberia and North China. This compression zone originated after the Paleozoic oceans which divided these cratons had closed. The Khanka terranes and Mesozoic accretionary wedge terranes of the Sikhote-Alin shifted along the strike-slip faults subparallel to the Asia Pacific margin. Strike-slip motions resulted in duplication of the primary tectonic zonation. 相似文献
999.
固体围压下完整花岗岩粘滑现象的实验研究 总被引:3,自引:0,他引:3
本文用完整的花岗岩样品在固体围压三轴实验装置上压缩,研究围压和应变速率对岩样变形破裂过程、粘滑应力降、粘滑复发间隔及样品主破裂几何分布的影响。结果表明,加载速率较低时,粘滑应力降较大,复发间隔较长且分布无规律。加载速率越大,粘滑应力降越小,复发间隔也近似相等,粘滑事件表现出准周期性。围压和应变率较低时,岩石的主破裂会演变成两个交叉的共轭断裂面;而围压和应变率较高时,岩石的主破裂则演变成单一断裂面或入字形断裂面。本文结果对认识中国大陆板内地震孕育、发生及重复过程;研究地震重复发生的机制及影响地震复发间隔的主要因素都有重要意义。 相似文献
1000.
通过实地考察及资料分析认为,共和7.0级地震发生于近东西向和近南北向构造带的交汇处。地震活动及震源机制表明:地震的发生与两组断裂共轭错动的力学机制有关。等震线长轴方向及展布状况与盆地形状、沉积物厚度和水文地质状况有关。 相似文献