应变固体潮资料与气压的相关分析及其改正的一种方法     

薄万举 《山西地震》1996,(2):24-28

通过对应变资料和气压资料的频谱分析，将固体潮频段的信息分别提取出来，再进行相关分析，二者显示出了很强的线性相关性。据此，对应变观测资料进行了气压改正，使应变固体潮调和分析的各项精度指标有了明显的提高，指出该方法的实用效果，同时，对气压改正中存在的问题也进行了讨论  相似文献   

基于阶跃函数的红树林凋落物变化模型研究   总被引：1，自引：0，他引：1       下载免费PDF全文

刘素青  韩维栋  李际平 《海洋科学》2007,31(2):35-39

由于凋落物随时间变化而存在峰值,按一般的回归方法或分段拟合方法均不能建立理想的凋落物随时间变化的模型。利用阶跃函数,解决了分段模型一直无法解决的两个问题:一是变点的数学确定方法,另一个是变点的连续性问题。建立了基于符号函数的阶跃函数模型,并以此为基础,提出了具有峰值的凋落物耦合模型。为了检验凋落物模型的效果,以雷州半岛红树林为例,结果表明,决定系数0.8以上,回归模型达到显著性水平。  相似文献   

初论韧性断裂构造形成时限的研究方法   总被引：1，自引：0，他引：1       下载免费PDF全文

吴小奇  刘德良  李振生 《地质科学》2007,42(1):199-208

韧性断裂构造形成时限的研究自提出以来得到了一定程度的发展,目前的研究方法主要有反应速率法、扩散速率法和应变速率法3种。最近的研究表明,对同一韧性剪切带,应变速率法和有限应变测量法所得构造形成时限均以10⁴a为数量级,并且均随着糜棱岩化程度的增加而逐渐减小;不同韧性剪切带的构造形成时限也均以10⁴a为数量级,其差异是由构造动力学条件不同引起的。利用应变速率法所得构造形成时限具有较好的内部一致性,这在一定程度上表明利用应变速率法测定构造形成时限是可行的。在超薄片厚度、不活动组份、糜棱岩化温度和最适用古应力计等的确定上目前仍存在争议。文中还对体积因子和糜棱岩化程度等对求算构造形成时限的影响以及构造形成时限的发展方向进行了深入讨论。构造形成时限研究整体来说仍处于探索阶段,目前只能达到半定量的程度,有待进一步的深入细致的工作,同时也有待于显微构造地质学、构造岩石学等相关学科的进一步发展。  相似文献   

Analysis of central western Europe deformation using GPS and seismic data   总被引：1，自引：0，他引：1  

Magdala Tesauro  Christine Hollenstein  Ramon Egli  Alain Geiger  Hans-Gert Kahle 《Journal of Geodynamics》2006,42(4-5):194-209

The kinematic field of central western Europe is characterized by relatively small movements (around 1–2 mm/year) and diffuse seismicity with earthquakes occurring mostly in the shallow crust (within 15 km), prevalently concentrated along the Alps and the European Cenozoic Rift System (ECRIS). In order to study and constrain the current crustal kinematic field we reconstructed the velocity and the strain field using permanent GPS stations, belonging to different networks (AGNES, EUREF, REGAL, RGP). The 2D strain rate tensor has been calculated using the method of least-squares collocation. Our results show that the area of maximum compression is located along the Alpine chain, where maximum values of 7 ± 2 nstrain/year are found, while maximum extension is measured between the Armorican Massif and the Massif Central, where values of 4 ± 2 nstrain/year are reached.The earthquakes with M > 3.0, have been used to estimate the seismic strain rates, while the style of the seismic deformation was reconstructed from the fault plane solutions (FPS) available from the literature. Relatively high values of seismic strain rates (around 10 nstrain/year) are measured along the Alpine Chain and the ECRIS. Results obtained by geodetic and seismic data are quite in agreement and reflect the different tectonic evolution of the geological features characterizing the area of study. The orientation of the compressional geodetic and seismic strain axes are NW-SE in most of the area of study, on account of the action of plate boundary forces. A rotation of the same axes to N-S direction along the eastern Alps, possibly related to the Adria convergence, is found.  相似文献   

The current strain distribution in the North China Basin of eastern China by least-squares collocation   总被引：1，自引：0，他引：1  

J.C. Wu  H.W. Tang  Y.Q. Chen  Y.X. Li 《Journal of Geodynamics》2006,41(5):462-470

In this paper, the velocities of 154 stations obtained in 2001 and 2003 GPS survey campaigns are applied to formulate a continuous velocity field by the least-squares collocation method. The strain rate field obtained by the least-squares collocation method shows more clear deformation patterns than that of the conventional discrete triangle method. The significant deformation zones obtained are mainly located in three places, to the north of Tangshan, between Tianjing and Shijiazhuang, and to the north of Datong, which agree with the places of the Holocene active deformation zones obtained by geological investigations. The maximum shear strain rate is located at latitude 38.6°N and longitude 116.8°E, with a magnitude of 0.13 ppm/a. The strain rate field obtained can be used for earthquake prediction research in the North China Basin.  相似文献   

高斯牛顿迭代法在地震计传递函数计算中的应用     

邵玉平 《四川地震》2006,(1):29-33

介绍了利用地震计对阶跃电流标定或稳态正弦电流标定的响应波形获取地震计传递函数的方法。对阶跃标定电流的响应波形进行傅立叶变换(FFT)和扣除阶跃信号频谱的运算获得地震计的幅频特性;从稳态正弦标定电流的响应波形可直接提取幅频特性,然后用高斯牛顿迭代法拟合出地震计传递函数的各个系数。该方法的最大优点是只需要已知幅频特性或其有限离散点的数值就可以拟合出地震计的传递函数,较目前常用的需要同时已知幅频和相频特性的拟合方法更为方便和实用。  相似文献   

用应变积累释放模型浅析山西地区地震活动特点     

梁向军  张瑞芳  贾建喜  孟晓琴  赵晓芸  刘敏娟 《山西地震》2006,(4):8-10,32

通过对山西地区历史地震地震活动性和应变能积累释放过程进行分析,得出,山西地区现在正处在应变能释放阶段,这一阶段可能持续80 a~90 a左右,在此期间将会发生5级~6级左右的地震;通过对现代3.0级地震两方面的分析得出,山西地区现在正处在能量主要积累阶段,估计在未来2 a~3 a之内,有发生4级以上地震的可能。  相似文献   

新疆钻孔应变异常与强震活动   总被引：3，自引：1，他引：3  

蒋靖祥  王在华  李川  丁毅敏 《内陆地震》2003,17(2):126-133

在新疆钻孔应变18年的观测期间，发生了6级以上强震17组(次)，其中7级以上地震5次，8级以上地震1次。钻孔应变资料在64％强震前记录到了异常变化。其中属于天山和塔里木地块周边的15例强震中，在儿例地震前钻孔应变资料出现了异常，占全部强震的73％。利用钻孔应变资料正确预报的地震数仅4例，占全部强震的23％，占天山及塔里木地块周边地震数的26％。在这些强震中距离台站250km范围以内发生的地震有7例，正确预报的有4例，占57％。  相似文献   

磁流变变阻尼半主动控制结构的仿真分析   总被引：6，自引：2，他引：6  

付伟庆  王玉铨  王焕定  张永山 《地震工程与工程振动》2003,23(4):165-170

由于高阶单步法已成功地应用于结构非线性分析及考虑时滞的主动控制等，显示了它的稳定、精度高和计算迅速等特点。用于结构振动控制的磁流变阻尼器属于速度相关型变阻尼半主动控制器，已有的一些算法，或因计算时间过长不能用于实际控制，或因需要事先经过学习训练，控制效果取决于训练学习的情况。因此，本文将高阶单步法应用于磁流变变阻尼半主动控制系统，采用开关控制和连续控制两种控制率对磁流变液的剪切强度进行调节。仿真计算表明，该控制算法是一种能用于结构实际控制的变阻尼有效算法.  相似文献   

The use of surface monitoring data for the interpretation of landslide movement patterns   总被引：4，自引：1，他引：4  

D.N. Petley  F. Mantovani  M.H. Bulmer  A. Zannoni 《Geomorphology》2005,66(1-4):133

The Tessina landslide is a large, seasonally active slope failure located on the southern slopes of Mt. Teverone, in the Alpago valley of NE Italy, consisting of a complex system that has developed in Tertiary Flysch deposits. The landslide, which first became active in 1960, threatens two villages and is hence subject to detailed monitoring, with high quality data being collected using piezometers, inclinometers, extensometers, and through the use of a highly innovative, automated Electronic Distance Measurement (EDM) system, which surveys the location of a large number of reflector targets once every 6 h. These systems form the basis of a warning system that protects the villages, but they also provide a very valuable insight into the patterns of movement of the landslide.In this paper, analysis is presented of the movement of the landslide, concentrating on the EDM dataset, which provides a remarkable record of surface displacement patterns. It is proposed that four distinct movement patterns can be established, which correspond closely to independently defined morphological assessments of the landslide complex. Any given block of material transitions through the four phases of movement as it progresses down the landslide, with the style of movement being controlled primarily by the groundwater conditions. The analysis is augmented with modelling of the landslide, undertaken using the Itasca FLAC code. The modelling suggests that different landslide patterns are observed for different parts of the landslide, primarily as a result of variations in the groundwater conditions. The model suggests that when a movement event occurs, displacements occur initially at the toe of the landslide, then retrogress upslope.  相似文献