First seismic record for intra-arc strike-slip tectonics along the Liquiñe-Ofqui fault zone at the obliquely convergent plate margin of the southern Andes     

D. Lange  J. Cembrano  A. Rietbrock  C. Haberland  T. Dahm  K. Bataille 《Tectonophysics》2008,455(1-4):14-24

A temporal seismic network recorded local seismicity along a 130 km long segment of the transpressional dextral strike-slip Liquiñe-Ofqui fault zone (LOFZ) in southern Chile. Seventy five shallow crustal events with magnitudes up to M_w 3.8 and depths shallower than 25 km were observed in an 11-month period mainly occurring in different clusters. Those clusters are spatially related to the LOFZ, to the volcanoes Chaitén, Michinmahuida and Corcovado, and to active faulting on secondary faults. Further activity along the LOFZ is indicated by individual events located in direct vicinity of the surface expression of the LOFZ. Focal mechanisms were calculated using deviatoric moment tensor inversion of body wave amplitude spectra which mostly yield strike-slip mechanisms indicating a NE–SW direction of the P-axis for the LOFZ at this latitude. The seismic activity reveals the present-day activity of the fault zone. The recent M_w 6.2 event near Puerto Aysén, Southern Chile at 45.4°S on April 21, 2007 shows that the LOFZ is also capable of producing large magnitude earthquakes and therefore imposing significant seismic hazard to this region.  相似文献   

渤海湾盆地新生界生油岩系底界面温度分布   总被引：3，自引：1，他引：2       下载免费PDF全文

龚育龄  王良书  刘绍文  李成  韩用兵  李华  蔡进功 《地质科学》2008,43(1):1-11

依据渤海湾盆地2000余口测温井的地温梯度数据、地层岩性描述、分层数据以及钻井资料,计算了该盆地各生油岩系底界面的温度。统计结果表明:渤海湾盆地沙河街组大部分凹陷区地层底界面温度介于90℃至150℃,目前仍具有大量生油的温度条件,而在隆起或一些凸起地区,该地层组段温度普遍小于90℃,未能达到生油的温度指标。东营组和孔店组地层也仍具有一定的生油温度条件。研究还表明:地层温度与地层界面埋深密切相关,温度随界面埋深的增大而升高,沉积厚度大的凹陷区地层界面温度大于沉积厚度小的凸起区或斜坡地带,说明地层界面埋深是决定地温高低的主要控制因素,而地温梯度对地层界面温度的影响相对较小。  相似文献   

Degradation in Cemented Marine Clay Subjected to Cyclic Compressive Loading   总被引：1，自引：0，他引：1  

G. Gerald Moses  S. Narasimha Rao 《Marine Georesources & Geotechnology》2003,21(1):37-62

The influence of cyclic loading on the strength and deformation behavior of cemented marine clay has been studied. This marine clay is of recent Pleistocene origin and deposited in a shallow water marine environment. Open pits were dug in sheeted enclosures and from these pits, undisturbed samples were taken for strength testing. A series of standard triaxial shear tests and stress controlled one-way cyclic load tests were conducted at consolidation stress ranges below and above the preconsolidation pressure. For the stress levels below the preconsolidation pressure, the cyclic loading has brought about the collapse of the cementation bond through an increase in strains, and at higher pressure ranges, the soil behaves like typical soft clay. This experiment studied the rate of development of strain and pore water pressure and shows that rate is a function of number of cycles, applied stress, and stress history. In addition, soil degradation during cyclic loading is studied in terms of Degradation Index. Attempt has been made to predict stain, pore water pressure, and degradation index through an empirical model.  相似文献   

河口潮位在频域内的一种插补模型     

韩丕康 《海洋工程》1997,(4)

若把河口潮位时间序列简单地看为单输入和输出线性系统模型的输入输出信号，借助频谱分析可以将它们在频域内的关系建立起来，用来进行潮位序列的插补，带通滤波技术的应用可使模型的计算精度大大提高  相似文献   

Evaluation of bending moments and shear forces at unit connections of very large floating structures using hydroelastic and rigid body analyses   总被引：1，自引：0，他引：1  

Byoung Wan Kim  Sa Young Hong  Jo Hyun Kyoung  Seok Kyu Cho 《Ocean Engineering》2007,34(11-12):1668-1679

This paper investigates the characteristics of bending moments, shear forces and stresses at unit connections of very large floating structures (VLFS) under wave loads. The responses of VLFS are calculated by solving multi-body motion equation considering hydroelasticity and connection stiffness. Hydroelastic responses are calculated by the direct method. Higher-order boundary element method (HOBEM) is used for fluid analysis and finite element method (FEM) is introduced for structural analysis. The equation of motion is modified to describe the unit connections by employing spring elements. Bending moments and shear forces at the connections are obtained from the dynamic equilibrium condition for pressures and inertia forces. Two types of VLFS units such as tandem arranged units and side-by-side arranged units are considered in the numerical examples. The influences of connection stiffness, wave frequency and heading angle on responses of VLFS are investigated through the numerical examples. Rigid body analysis along with hydroelastic analysis is also carried out in the numerical analysis and comparison of those two approaches is discussed.  相似文献   

Diet restriction induced autophagy: a lysosomal protective system against oxidative- and pollutant-stress and cell injury   总被引：1，自引：0，他引：1  

Moore MN 《Marine environmental research》2004,58(2-5):603-607

Nutrient deprivation or dietary restriction (DR) confers protection against ageing and stress in many animals and induced lysosomal autophagy is part of this mechanism. The effects of dietary restriction on the toxicity of copper and the polycyclic aromatic hydrocarbon phenanthrene have been investigated in the common marine mussel Mytilus edulis. The findings show that DR-induced autophagy facilitates the recovery of the digestive gland (i.e., molluscan liver analogue) from cell injury caused by both copper and phenanthrene. It is inferred that DR-induced autophagy and lysosomal proteolysis results in improved cellular "housekeeping" through the more efficient removal of oxidatively and pollutant damaged proteins (e.g., protein carbonyls, protein adducts, etc.) and that this contributes to stress resistance.  相似文献   

福建戴云山隧道断层性质与稳定性研究     

余成伟  刘星 《云南地质》2008,27(4):509-513

隧道断层（F2）为张性正断层,破坏原岩中较为对称的应力平衡,加之带内岩石破碎,节理裂隙发育,使得断层更加容易坍塌和涌水。建议采用稳定掌子面法和专门支护保证硐室稳定。  相似文献   

地理信息服务中数据传输性能分析   总被引：2，自引：0，他引：2  

王玉海  张新城  崔铁军  陈应东 《测绘科学》2008,33(6):146-148

地理信息服务系统具有数据密集型和计算密集型的特点,对网络环境的设置有着特殊的需求。本文从地理信息服务系统中对数据传输应用的角度出发,从网络数据传输协议的传输层和应用层两个层次分析地理信息服务系统应用的特殊性,并根据系统应用的特殊需求提出相应的解决方案,提高整个应用系统中各类数据传输的效率、性能和系统运行的稳定性,提高地理信息服务系统为多用户提供地图服务、位置服务以及各种应用服务的综合能力。提高系统适应多用户并发访问海量数据的地图服务作业和频繁访问实效性很强的位置服务作业的能力。  相似文献   

斜坡应力分布的系统测试与反演分析     

沈军辉  崔建凯  徐进  贾留杰 《工程地质学报》2008,16(5):616-619

采用简易、快速、经济的洞壁应力恢复法对某工程边坡勘探平硐洞壁应力场作了系统测试, 并采用FLAC2D软件对测试成果作了斜坡初始应力的反演分析。结果表明, 斜坡应力场随深度变化具有明显分带性, 应力量值随硐深曲线具有典型的驼峰式特征, 与理论分析结果相符, 表明该方法能较好地应用于斜坡应力场的系统测试和研究。成果对认识斜坡岩体的变形破裂及卸荷特征等具有重要意义。  相似文献   

Strain localization due to structural in-homogeneities in the Central European Basin System     

Mauro Cacace  Ulf Bayer  Anna Maria Marotta 《International Journal of Earth Sciences》2008,97(5):899-913

The large-scale crustal deformations observed in the Central European Basin System (CEBS) are the result of the interplay between several controlling factors, among which lateral rheological heterogeneities play a key role. We present a finite-element integral thin sheet model of stress and strain distribution within the CEBS. Unlike many previous models, this study is based on thermo-mechanical data to quantify the impact of lateral contrasts on the tectonic deformation. Elasto-plastic material behaviour is used for both the mantle and the crust, and the effects of the sedimentary fill are also investigated. The consistency of model results is ensured through comparisons with observed data. The results resemble the present-day dynamics and kinematics when: (1) a weak granite-like lower crust below the Elbe Fault System is modelled in contrast to a stronger lower crust in the area extending north of the Elbe Line throughout the Baltic region; and (2) a transition domain in the upper mantle is considered between the shallow mantle of the Variscan domain and the deep mantle beneath the East European Craton (EEC), extending from the Elbe Line in the south till the Tornquist Zone. The strain localizations observed along these structural contrasts strongly enhance the dominant role played by large structural domains in stiffening the propagation of tectonic deformation and in controlling the basin formation and the evolution in the CEBS.  相似文献