地震计时域标定的噪声数据处理   总被引：2，自引：1，他引：1  

周云耀 《大地测量与地球动力学》2004,24(4):123-127

分析了在甚宽频带地震计的时域标定中存在的各种噪声，探讨了相应的处理方法，重点阐述了对阶跃标定影响最大的长周期漂移噪声的处理方法——漂移曲线拟合法。  相似文献   

基于形变监测成果探讨万州枇杷坪古滑坡稳定性     

韩文心 《中国地质灾害与防治学报》2007,18(3):97-101

枇杷坪古滑坡位于重庆市万州区东缘,是三峡库区重点勘察的滑坡之一。近年来滑体部分地区出现蠕滑变形,存在局部复活的可能。枇杷坪古滑坡及移民房屋稳定性监测预警系统始建于2004年初,主要监测手段为GPS及精密水准测量。2a多的监测成果表明,枇杷坪古滑坡局部出现较大的顺坡向位移变形及不均匀沉降。滑体出现蠕滑变形的主要原因:①库水位的升高使地下水位升高;②频繁的人类工程活动。文章依据监测成果,运用Winsurf软件绘制出滑体水平形变场及垂直形变场,综合分析位移监测信息,并运用Mapinfo地理信息系统平台,依据滑体的形变场,试勾描出枇杷坪的强变形区域,该区域对应在滑体中段的中前部,区域内监测点均一致朝向长江方向滑移及倾斜。文章拟通过滑坡变形区的划分,探讨滑体的稳定性区划、变形特征及发展趋势。  相似文献   

A possible link between gabbros bearing High Temperature Iddingsite alteration and huge pegmatoid intrusions: The Society Islands, French Polynesia     

Jean-Philippe Clment  Martial Caroff  Patrick Dudoignon  Patrick Launeau  Marcel Bohn  Joseph Cotten  Sylvain Blais  Grard Guille 《Lithos》2007,96(3-4):524-542

This paper reports new field observations and new petrological, textural and geochemical data on two gabbroic intrusions and one pegmatoid dyke from the French Polynesian islands Maupiti and Bora Bora, respectively. Olivine crystals from the Faataufi and Barque de Hiro gabbros (Maupiti) include High Temperature Iddingsite (HTI), exhibiting three distinct morphological facies. Chemical and crystallographical data performed by electron microprobe, scanning microscope, X-ray diffractometry and Near InfraRed spectroscopy show that HTI results from modifications of olivine structure through intense hydroxylation and Fe-oxidation. The HTI-free 120 m-wide Cloche de Hiro dyke (Bora Bora) exhibits a textural zonation from heterogranular/intergranular gabbro (peripheral part) to typical pegmatoid (inner area). We propose a textural tetrahedral classificatory diagram which can be used to clearly distinguish the textural characteristics of the pegmatoids from those of the other coarse-grained samples. Through comparison with a lava flow containing vesicle-rich segregation sheets, we suggest that the Cloche de Hiro dyke may correspond to a huge segregation structure derived from a Maupiti-type HTI-bearing gabbro through a vapor-differentiation process. Both intrusions might be considered as representative of two superposed levels in a vertically arranged magmatic complex. In this view, the Maupiti gabbroic bodies would represent the lower part of the postulated system. Under high oxygen fugacity, olivine crystals would have undergone important modifications of their structure, leading to HTI. The huge Bora Bora pegmatoid dyke would be the upper part of the complex. After expulsion from the HTI-bearing gabbroic solidification zone by build-up of gas pressure, vesicle-rich residual melt would have gathered into a shallow level and crystallized there as a pegmatoid body.  相似文献   

滇西实验场及邻区4级调制地震与中强地震的关系   总被引：1，自引：0，他引：1  

杨芬  金明培  赵家本 《国际地震动态》2007,(4):8-13

利用1972年1月1日—2005年12月31日云南省地震遥测台网的地震正式目录,对正式目录中的中强以上地震进行了余震删除。利用已删除余震的正式目录,分析实验场及邻区4.0~4.5级调制地震与中强地震的关系,总结历史震例得到:实验场及邻区发生4.0~4.5级调制地震,其后发生中强以上地震的可能性为81%,平均间隔时间为9.6月,而且中强震发震地点与4.0~4.5级调制地震发震地点相关性较好,平均相隔距离为85 km。  相似文献   

我国科学数据共享现状   总被引：8，自引：0，他引：8  

路鹏  苗良田  莫纪宏  李志雄  李学良  孙士鋐  王松 《国际地震动态》2007,(6):26-32

国家财政性资金资助的科技活动产生的科学数据是我国科学数据的主体,为了了解我国科学数据共享的现状,规范科学数据汇交、共享、管理,科技部以项目任务的形式下达了科学数据共享研究。本文以基础调查为依据,展示科学数据共享现状、立法现状、管理模式,并提出了几点认识。  相似文献   

GPS高频数据处理方法及其在地震学中的应用研究进展   总被引：7，自引：0，他引：7  

孟国杰  任金卫  金红林  李鹏 《国际地震动态》2007,(7):26-31

本文简要介绍了GPS高频观测数据处理方法的特征,阐述了GPS高频观测数据在地震动态位移分析、震源破裂反演方面的应用研究进展。并对今后的发展趋势提出了自己的看法,认为在我国及时开展GPS高频数据处理方法和相关的应用研究是十分必要的。  相似文献   

地震电磁卫星观测物理量简介   总被引：1，自引：0，他引：1  

欧阳新艳 《国际地震动态》2007,(8):54-58

地震引发电离层扰动反映在某些特定的物理量上已经得到人们的共识,但其中哪些量反映的特征最明显,最有利于提取地震电离层异常仍然不明确,需要进一步的深入研究。本文介绍了法国的DEMETER、乌克兰的SICH-1M、意大利的ESPER IA及俄罗斯的COMPASS-2等几个主要地震电磁卫星的观测物理量,以资参考。  相似文献   

岷县5.2级地震前兆异常分析   总被引：2，自引：0，他引：2  

徐辉  白亚平  康庆强  姚军  燕明芝 《高原地震》2007,19(3):25-28

用兰州、天水、通渭、武都4台站地电数字化资料观测结果，对2003年11月13日在岷县发生的Ms5．2级地震进行分析，其结果表明，在该地震发生前地电前兆出现了多项短临异常，这些短临异常特征明显，从异常开始至结束，展现为时间短、幅度大、恢复快这一特点。可为地震短临预报提供重要的参考依据。  相似文献   

Fluorapatite surface composition in aqueous solution deduced from potentiometric, electrokinetic, and solubility measurements, and spectroscopic observations     

Claire Chaïrat  Eric H. Oelkers  Jacques Schott 《Geochimica et cosmochimica acta》2007,71(24):5888-5900

The surface chemistry of fluorapatite in aqueous solution was investigated using electrokinetic techniques, potentiometric titrations, solubility measurements, and attenuated total reflection infrared spectroscopy. All methods indicate the formation of Ca/F depleted, P enriched altered layer via exchange reactions between H⁺ and Ca²⁺, and OH⁻ and F⁻ at the fluorapatite (FAP) surface. Observations suggest that this leached layer has a di-calcium phosphate (CaHPO₄) composition and that it controls the apparent solubility of FAP. Electrokinetic measurements yield an iso-electric point value of 1 ± 0.5 consistent with a negatively charged FAP surface at pH > 1. In contrast, surface titrations give an apparent pH of point of zero charge of ∼7.7, consistent with a positively charged surface at pH < 7.7. These differences are shown to stem from proton consumption by both proton exchange and dissolution reactions at the FAP surface. After taking account for these effects, FAP surface charge is shown to be negative to at least pH 4 by surface titration analysis.  相似文献   

Cementation of kerogen-rich marls by alkaline fluids released during weathering of thermally metamorphosed marly sediments. Part I: Isotopic (C,O) study of the Khushaym Matruk natural analogue (central Jordan)     

Serge Fourcade  Laurent Trotignon  Philippe Boulvais  Isabelle Techer  Marcel Elie  Didier Vandamme  Elias Salameh  Hani Khoury 《Applied Geochemistry》2007

The Khushaym Matruk site in central Jordan may represent a natural analogue depicting the interaction of alkaline solutions with a clayey sedimentary formation or with clay-rich confining barriers at the interface with concrete structures in waste disposal sites. In this locality, past spontaneous combustion of organic matter in a clayey biomicritic formation produced a ca. 60 m-thick layer of cement-marble containing some of the high-temperature phases usually found in industrial cements (e.g., spurrite, brucite, and Ca-aluminate). A vertical cross-section of the underlying sediments was used in order to study the interaction between cement-marbles and neighbouring clayey limestones under weathering conditions. A thermodynamic approach of the alteration parageneses (calcite–jennite–afwillite–brucite and CSH phases) in the cement-marbles constrains the interacting solutions to have had pH-values between 10.5 and 12. Over 3 m, the sediments located beneath the metamorphic unit were compacted and underwent carbonation. They display large C and O isotopic variations with respect to “pristine” sediments from the bottom of the section. Low δ¹³C-values down to −31.4‰/PDB show the contribution of CO₂ derived from the oxidization of organic matter and from the atmosphere to the intense carbonation process affecting that particular sedimentary level. The size of the C isotopic anomalies, their geometrical extent and their coincidence with the variations of other markers like the Zn content, the structure of organic matter, the mineralogical composition, all argue that the carbonation process was induced by the percolation of high pH solutions which derived from the alteration of cement-marbles. The temperature of the carbonation process remains conjectural and some post-formation O isotopic reequilibration likely affected the newly-formed carbonate. Carbonation induced a considerable porosity reduction, both in fractures and matrixes. The Khushaym Matruk site may have some bearing to the early life of a repository site, when water saturation of the geological formations hosting the concrete structures is incomplete, enabling simultaneous diffusion of alkaline waters and gaseous CO₂ in the near field.  相似文献