石嘴山水氡低值变化的成因分析     

李英  赵卫明 《高原地震》2000,12(4):47-52

对宁夏石嘴山氡1995－2000年的资料进行了详细研究,对观测环境进行了细致的调查分析,得出该台氡值历6-8月的低值变化主要受降雨影响所致,不是地震前兆异常。  相似文献   

Amplification effects from earthquakes and ambient noise in the Dead Sea rift (Israel)   总被引：1，自引：0，他引：1  

Y. Zaslavsky  A. Shapira  A. A. Arzi 《Soil Dynamics and Earthquake Engineering》2000,20(1-4)

Seven sites were instrumented in the Parsa area located in the seismically active Dead Sea rift system. Moderate and weak motions generated by earthquakes and ambient noise were used to identify amplifications due to geological and topographic effects.Three observation methods were applied to estimate site effects: (1) conventional soil–bedrock station-pair spectral ratios for earthquake motions and microtremors; (2) horizontal-to-vertical component spectral ratios for shear-waves observed simultaneously at a site (receiver function estimates) and (3) horizontal-to-vertical spectral ratios of microtremor measurements (Nakamura estimate). The site response spectra of soil sites exhibited significant peaks between 1 and 3 Hz with amplification factors typically within the range of 2.5–4.0. A bedrock site on the high plateau near the escarpment top showed a peak between 2 and 3 Hz, mainly due to an EW oscillation of the NS topographic feature. Our observations indicated that seismograms recorded in the tunnel were either enriched or depleted at certain frequencies owing to interference of incident and surface-reflected waves.  相似文献   

Mega-fold interference patterns in the Beishan orogen (NW China) created by change in plate configuration during Permo-Triassic termination of the Altaids     

《Journal of Structural Geology》2013

Kilometer-size fold interference patterns in the Beishan Orogenic Collage (BOC) in the southernmost Altaids formed by fold superimposition in fossiliferous Permian sedimentary rocks. First-phase (F₁), upright and almost north-trending folds, were refolded by E- to ENE-trending F₂ folds, whose axial planes and axes are vertical or subvertical. From east to west there is a regional change in style of interference patterns from lobate–cuspate-, to crescent- to mushroom-shape. This variation is accompanied by a westward decrease in the F₂ interlimb angle and related to a higher percentage of coarse-grained clastic rocks, suggesting a dependence of the F₂ deformation on lithology. Axial planar slaty cleavages are well developed in F₁ and poorly developed in F₂ folds. The superposed folds mainly underwent flexural-slip and flexural flow folding to give rise to the lobate–cuspate pattern, and to the crescent pattern caused by flattening and flexural flow folding where the sediments were unconsolidated and enriched in fluids. The two folding events are interpreted to result from a major change in plate configuration that caused the inversion of an inter-arc basin during the final amalgamation of the BOC in the latest Permian to early to mid-Triassic. The two folding events bracketed between a maximum detrital zircon age of <273 Ma, and the youngest age of an intruded dyke at 219.0 ± 1.2 Ma suggest rapid plate reconfiguration related to final amalgamation of the Altaids orogen.  相似文献   

高压直流输电对磁电场观测的影响   总被引：1，自引：0，他引：1  

王向阳  王洪峰  黄春玲  李民 《山西地震》2013,(3):18-22

以山西地磁场观测台站和山西、宁夏、山东部分地电场台站观测为例,分析其受宁夏一山东±660千伏直流输电工程运行的干扰情况。结果表明,高压直流输电工程的运行对山西地磁场观测及送受端换流站附近的宁夏、山东地电场观测影响明显,而对于直流输电工程中段的山西地电场观测无明显影响。  相似文献   

浚县地震台地磁观测受高压直流输电干扰的分析     

邢力  张惠霞  郑培玲  何香玲 《高原地震》2013,(3):31-35

随着宁夏至山东电网高压线路的投入运行,对河南浚县地震台的地磁观测（FHD-2质子矢量磁力仪）造成了一定的干扰。分析了高压直流输电干扰的动态特征,介绍了干扰的预处理方法。  相似文献   

用模式识别法消除气象传真图中的某些干扰     

余乃枞  郑郁正  郭乃渝 《成都信息工程学院学报》1991,(1)

本文介绍利用模式识别方法消除气象传真图象中某些干扰的方法。实践证明:采用3×3的窗口,1024个模块,可消除了1～3点的孤立麻点干扰,16点以内的孤立横线干扰,同时还对线条边缘起平滑整形作用。使图象质量得到改善。此法简单易行,实时性强,效果良好。  相似文献   

厦门台数字化潮汐资料的背景变化及其主要干扰因素     

熊先保  黄晓华  张远城  李恩建  金涛 《福建地震》2006,(Z2)

利用快速Fourier变换分析方法,对厦门台数字化潮汐资料的背景变化及其主要干扰因素进行了初步探讨,并对其存在的原因给出了可能的解释;和内陆台站的相应资料对比后表明,并非所有的台站测项所观测到的固体潮资料中,M2波都会占绝对优势;临海台站在作资料分析时,对M2波的分析应该是主要的,而内陆型台站应该综合考虑其它波群的影响;同一台站的不同测项受到主要干扰的机制是不同的,厦门台受海潮的干扰机制是,厦门台处于相干海潮波的波峰或波谷处,且该海潮波的周期又和M2波的非常接近,气压的干扰机制是,气压扰动形成的压力差以波动形式直接作用在洞体应变仪的含铌特种因瓦棒或传感器探头上,使得其记录曲线中叠加了多种波的成份。  相似文献   

地电阻率背景值初探──以大同－阳高和忻州2次地震为例     

郭宝娥  张德信 《山西地震》1996,(1)

用山西地电台网的资料，从震前变化的一些现象入手，找到识别和消除非地震异常及背景影响的方法，对地电阻率背景变化场作了初步的物理解释，并将此方法用于１９９１年震情分析中，取得较好结果。  相似文献   

关系处理中要素重叠的自动判别     

武芳 《测绘学院学报》1997,(1)

关系处理一直是自动制图综合中解决起来困难比较多的一个问题,而解决关系处理的前提则是要素重叠位置的自动识别。本文着重讨论数据库条件下进行要素重叠自动识别的方法及其在编图实践中的应用。  相似文献   

根据水力削减法评价玉门镇水源地允许开采量     

曹兴山  赫明林等 《甘肃地质》2001,10(2):81-88,80

依据玉门镇拟选供水水源地干扰抽水试验资料 ,用水力削减法对供水井群进行干扰涌水量计算 ,在开采期内开采量不变条件下对各开采井水位下降值进行预报 ,并依据计算结果评价其允许开采量。  相似文献