Similarities between strike-slip faults at different scales and a simple age determining method for active faults   总被引：1，自引：0，他引：1  

Young-Seog Kim  David J. Sanderson 《Island Arc》2004,13(1):128-143

Abstract Several differently scaled strike‐slip faults were examined. The faults shared many geometric features, such as secondary fractures and linkage structures (damage zones). Differences in fault style were not related to specific scale ranges. However, it was recognized that differences in style may occur in different tectonic settings (e.g. dilational/contractional relays or wall/linkage/tip zones), different locations along the master fault or different fault evolution stages. Fractal dimensions were compared for two faults (Gozo and San Andreas), which supports the idea of self‐similarity. Fractal dimensions for traces of faults and fractures of damage zones were higher (D ～1.35) than for the main fault traces (D ～1.005) because of increased complexity due to secondary faults and fractures. Based on the statistical analysis of another fault evolution study, single event movements in earthquake faults typically have a maximum earthquake slip : rupture length ratio of approximately 10^?4, although this has only been established for large earthquake faults because of limited data. Most geological faults have a much higher maximum cumulative displacement : fault length ratio; that is, approximately 10^?2 to 10^?1 (e.g. Gozo, ～10^?2; San Andreas, ～10^?1). The final cumulative displacement on a fault is produced by accumulation of slip along ruptures. Hence, using the available information from earthquake faults, such as earthquake slip, recurrence interval, maximum cumulative displacement and fault length, the approximate age of active faults can be estimated. The lower limit of estimated active fault age is expressed with maximum cumulative displacement, earthquake slip and recurrence interval as T ? (d_max /u) · I(M).  相似文献   

红砂岩高陡岩质边坡稳定性分析及治理   总被引：2，自引：0，他引：2  

倪俊 《岩土力学》2004,25(6):981-983

充分利用边坡失稳前自身抗滑能力进行高陡边坡治理，结合工程实例，提出了主动性公路边坡治理的思路。分别利用极限平衡法和有限元数值法，综合考虑了两种方法的优缺点，对红砂岩高陡边坡进行了全面的稳定性分析，并针对性地提出了经济合理的治理方案。  相似文献   

Imaging the ramp–décollement geometry of the Chelungpu fault using coseismic GPS displacements from the 1999 Chi-Chi, Taiwan earthquake     

Kaj M. Johnson  Paul Segall 《Tectonophysics》2004,378(1-2):123-139

We use coseismic GPS data from the 1999 Chi-Chi, Taiwan earthquake to estimate the subsurface shape of the Chelungpu fault that ruptured during the earthquake. Studies prior to the earthquake suggest a ramp–décollement geometry for the Chelungpu fault, yet many finite source inversions using GPS and seismic data assume slip occurred on the down-dip extension of the Chelungpu ramp, rather than on a sub-horizontal décollement. We test whether slip occurred on the décollement or the down-dip extension of the ramp using well-established methods of inverting GPS data for geometry and slip on faults represented as elastic dislocations. We find that a significant portion of the coseismic slip did indeed occur on a sub-horizontal décollement located at 8 km depth. The slip on the décollement contributes 21% of the total modeled moment release. We estimate the fault geometry assuming several different models for the distribution of elastic properties in the earth: homogeneous, layered, and layered with lateral material contrast across the fault. It is shown, however, that heterogeneity has little influence on our estimated fault geometry. We also investigate several competing interpretations of deformation within the E/W trending rupture zone at the northern end of the 1999 ground ruptures. We demonstrate that the GPS data require a 22- to 35-km-long lateral ramp at the northern end, contradicting other investigations that propose deformation is concentrated within 10 km of the Chelungpu fault. Lastly, we propose a simple tectonic model for the development of the lateral ramp.  相似文献   

Neotectonic deformation in the transition zone between the Dead Sea Transform and the East Anatolian Fault Zone, Southern Turkey: a palaeomagnetic study of the Karasu Rift Volcanism     

O Tatar  J.D.A Piper  H Gürsoy  A Heimann  F Kobulut 《Tectonophysics》2004,385(1-4):17-43

In southern Turkey ongoing differential impingement of Arabia into the weak Anatolian collisional collage resulting from subduction of the Neotethyan Ocean has produced one of the most complex crustal interactions along the Alpine–Himalayan Orogen. Several major transforms with disputed motions, including the northward extension of the Dead Sea Fault Zone (DSFZ), meet in this region. To evaluate neotectonic motion on the Amanos and East Hatay fault zones considered to be northward extensions of the DSFZ, the palaeomagnetism of volcanic fields in the Karasu Rift between these faults has been studied. Remanence carriers are low-Ti magnetites and all except 5 of 51 basalt lavas have normal polarity. Morphological, polarity and K–Ar evidence show that rift formation occurred largely during the Brunhes chron with volcanism concentrated at 0.66–0.35 Ma and a subsidiary episode at 0.25–0.05. Forty-four units of normal polarity yield a mean of D/I=8.8°/54.7° with inclination identical to the present-day field and declination rotated clockwise by 8.8±4.0°. Within the 15-km-wide Hassa sector of the Karasu Rift, the volcanic activity is concentrated between the Amanos and East Hatay faults, both with left lateral motions, which have rotated blocks bounded by NW–SE cross faults in a clockwise sense as the Arabian Block has moved northwestwards. An average lava age of 0.5 Ma yields a minimum cumulative slip rate on the system bounding faults of 0.46 cm/year according with the rate deduced from the Africa–Arabia Euler vector and reduced rates of slip on the southern extension of the DSFZ during Plio-Quaternary times. Estimates deduced from offsets of dated lavas flows and morphological features on the Amanos Fault Zone [Tectonophysics 344 (2002) 207] are lower (0.09–0.18 cm/year) probably because they are limited to surface fault breaks and do not embrace the seismogenic crust.Results of this study suggest that most strike slip on the DSFZ is taken up by the Amanos–East Hatay–Afrin fault array in southern Turkey. Comparable estimates of Quaternary slip rate are identified on other faults meeting at an unstable FFF junction (DSFZ, East Anatolian Fault Zone, Karatas Fault Zone). A deceleration in slip rate across the DSFZ and its northward continuation during Plio-Quaternary times correlates with reorganization of the tectonic regime during the last 1–3 Ma including tectonic escape within Anatolia, establishment of the North and East Anatolian Fault Zones bounding the Anatolian collage in mid–late Pliocene times, a contemporaneous transition from transpression to transtension and concentration of all basaltic magmatism in this region within the last 1 Ma.  相似文献   

Complex kinematic rupture of the Mw 5.9, 1999 Athens earthquake as revealed by the joint inversion of regional seismological and SAR data     

D. Baumont  O. Scotti  F. Courboulex  N. Melis 《Geophysical Journal International》2004,158(3):1078-1087

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Instability of a periodic system of faults     

Michel Campillo  Cristian Dascalu  Ioan R. Ionescu 《Geophysical Journal International》2004,159(1):212-222

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The 2003 Bam (SE Iran) earthquake: precise source parameters from satellite radar interferometry   总被引：8，自引：0，他引：8  

R. Wang  Y. Xia  H. Grosser  H.-U. Wetzel  H. Kaufmann  J. Zschau 《Geophysical Journal International》2004,159(3):917-922

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Paleo-earthquake studies on the eastern section of the Kunlun fault   总被引：1，自引：0，他引：1  

李春峰  贺群禄  赵国光 《地震学报(英文版)》2005,18(1):64-71

Introduction East Kunlun active fault is one of the largest sinistral slip fault zones in northern Tibetan Pla-teau. The fault tails primarily after the ancient eastern Kunlun suture zone, which was reactivatedby the northward subduction of the Indian plate beneath the Eurasian plate. The western end of thefault starts near the western flank of the Buxedaban peak in Qinghai Province. The fault then ex-tends eastwards through the Kusai Lake, Xidatan, Dongdatan, Alag Lake, Tuosuo Lak…  相似文献   

CGD-1型大口径全套管冲击抓斗的设计和应用          下载免费PDF全文

冯起赠  宋志彬  王年友 《探矿工程》2005,32(6):38-40

CGD－1型大口径全套管冲击抓斗主要是配套全套管钻机施工而研制的。该抓斗主要适用于复杂地层的施工。介绍了该抓斗的技术参数、性能特点、主要结构及试验情况。  相似文献   

Slope stability analysis using evolutionary optimization techniques          下载免费PDF全文

A.H. Gandomi  A.R. Kashani  M. Mousavi  M. Jalalvandi 《国际地质力学数值与分析法杂志》2017,41(2):251-264

Slope stability optimization, in the presence of a band of a weak layer between two strong layers, is accounted for in complicated geotechnical problems. Classical optimization algorithms are not suitable for solving such problems as they need a proper preliminary solution to converge to a valid result. Therefore, it is necessary to find a proper algorithm which is capable of finding the best global solution. Recently a lot of metaheuristic algorithms have been proposed which are able to evade local minima effectively. In this study four evolutionary algorithms, including well‐known and recent ones, such as genetic algorithm, differential evolution, evolutionary strategy and biogeography‐based optimization (BBO), are applied in slope stability analysis and their efficiencies are explored by three benchmark case studies. Result show BBO is the most efficient among these evolutionary algorithms and other proposed algorithms applied to this problem. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献