Determining gaseous composition of fluid inclusions with quadrupole mass spectrometer

Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then determined with the sensitive QMS instrument. The method is characterized by high sensitivity and high accuracy with the relative standard deviation (RSD,n=6) of less than 3%. It has been successfully used for analyzing fluid inclusions. The analytical results meet the requirement of geological study.     

上海数字强震观测网

上海市数字强震观测网是我国第1个具有一定规模的数字强震观测网，是上海市“九五”期间建设完成的，它由3部分组成；地面观测网，结构观测网和深井强震观测系统，每一部分都有不同的功能和目的，本文详细介绍该强震网的整个概况。功能及取得的部分观测成果。     

云南丽江地区断裂构造岩岩组动力学研究

丽江地区构造岩岩组动力学研究表明，研究区内中更新世末构造主压应力保持在北西至北西西方向变化；晚更新世中期之后构造主压应力方向则以北北东至北东方向为主变化，并有逐渐向近南北向转化的特点。因此玉龙雪山东麓断裂在中更新世末曾有过左旋压扭活动为主的历史，兼有左旋、右旋的活动过程，1996年2月3日丽江M7．0地震的破裂过程继承了晚更新世后期断裂的活动特点。     

2001年三次6级左右地震前西昌地磁的虚假异常研究

2001年，在西昌地磁台300km范围内连续发生了三次6级左右地震；即2月23日在西昌北200km的四川雅江县境内发生的6．0级地震；5月24日在西昌西南140km的盐源县内境内发生的MS5．8地震，10月27日在西昌西南260km的云南永胜发生的MS6．0地震。震前，西昌地磁台各相对观测记录分量和绝对观测量都发生了明显的异常变化。研究结果表明，由于邻近基建施工，使观测环境发生改变，引起大幅度虚假异常，这些异常 尽管与三次地震对应较好，但不是先兆异常。     

国际地磁参考场在我国地磁基础研究中的应用

国际地磁参考场资料在我国得到广泛应用。利用国际地磁参考场资料，我国学者研究了高斯分析、地球磁场模型及其源场可能位置、重磁关系、核幔耦合、地磁场能量、地球非偶极子磁场西向漂移等。在绘制中国地磁等值图中也利用了某些国际地磁参考场资料。     

Earthquake—generating Structure Revealed by 1999 Sichuan mianzhu Earthquake Sequence with Ms=5.0

Through the accurate determination of hypocenter location,the measurement of the main focal mechanism solutions and the analyses of time dependent processes for Sichuan Mianzhu earthquake sequence with Ms=5.0 occurred along the middle segment of Longmenshan fault zone on November 30,1999,the distribution of focal depth section,the stress relase and seismicity features are given to reveal the earthquake-geneating structure of the earthquake sequence.The obtained results show the activity features for this sequence as follows:(1) There is no obvious foreshock,the accumulated strain energy releases in nearly pulse way,fluctuation of the seismic activity level is not quite evident during the duration of the sequence,and the statistical relation between the large events and the small events is less compatible with the traditional G-R estimation;(2) The epicenters of the earthquake sequence are not distributed on the main Longmenshan piedmont faults emerging out ground,but near the hidden Longmenshan piedmont faults.The direction of epicenter distribution is not very coincident with the fault strikes.The microscopic epicenters are relatively far from the macroscopic epicenters,The focal depths range from 5km to 16km;(3) The fractures of focal fault plane with the NE strike appear out the strike-slip displacement with a few overthrust components under the major principal compressive stress of NNE direction.From these,we consider it should be paid more attentions to the underground hidden faults near the ground fault zone on a large scale for their generating earthquake risk.     

Focal Fault of the 1999 Datong Ms5.6 Earthquake in Shanxi Province

Several earthquakes with Ms≥5.0 occurred in the Datong seismic region in 1989,1991 and 1999,The precise focus location of the earthquake sequence was made by the records of the remote sensing seismic station network in Datong.Using that data together with macro-intensity distribution and focal mechanism solutions,we analyze the difference among three subsequences.The results show that the focal fault of the 1999 Ms 5.6 earthquake was a NWW-trending left-lateral strike-slip fault.It is 16km long and 12km wide.It developed at the depth of 5km and is nearly vertical in dip.The two previous earthquake subsequences,however,were generated by activity along NNE-trending right-lateral strike-slip fault.It can be found that the rupture directioin of the 1999 earthquake has changed.It is generally found that a rupture zone has more than two directions and has different strength along these two directions.The complicate degree of focal circumstance is related to the type of earthquake sequences.There is the NE-trending Dawangcun fault and the NW-trending Tuanbu fault in the seismic region,but no proof indicates a connection between focal faults and these two tectonic faults.The feature that focal faults of three subsequences are strike-slip is different from that of the two tectonic faults.It is suggested that the 1999 earthquake subsequence was possibly generated by a new rupture.     

Extracting coseismic deformation of the 1997 Mani earthquake with differential interferometric SAR

Introduction The development and application of Interferometric Synthetic Aperture Radar (InSAR) have a close relationship with the sensors development of Synthetic Aperture Radar (SAR). The conception of SAR is proposed comparatively to the real aperture radar antenna. It is well known that the longer the antenna is, the higher the observation resolution will be. Just limited by the length of the antenna, the resolution of real aperture radar is generally very low and cannot meet the r…     

大姚地热动态特征分析

通过大姚高精度水温观测井水地质、井孔条件的分析，震例观测资料、实验观测数据的处理，以及井水水质分析结果，表明大姚水温周期性变化的突出位置是井深75m左右，根本原因是该地层石膏脉稳定释热，含水层热水与井内冷水混合过程中，在通道内形成钙盐类沉淀物（如CaSO4CaCO3），堵塞对流通道，含水层内外压差突破被阻塞通道，热水反复侵入井内，便形成水温周期性变化。地震的孕育、发生和调整过程，由于应力场作用，产生附加地热场，水温基值发生变化，周期畸变或消失，这种附加地热动态是可以恢复的。所以认为大姚地热动态是井区特殊地层地热信息的反映。