Study of crustal structure with S—wave data from Maqen—Jingbian profile

2-D crustal velocity structure and vp/vs are obtained by processing and interpretation of S-wave data from Maqen-Jingbian deep seismic sounding(DSS)profile.The result shows that there exist obvious differences in 2-D S-wave velocity structure and vp/vs ratio structure along the profile.The S-wave velocities are low and vp/vs ration is high for the westem section of the profile and Haiyuan region,while they are normal for the middle and eastern sections.The changes in lithologic characters of two major anomalous zones are discussed according to lateral variation of S-wave velocity structure and vp/vs ratio structure.It is concluded that the development and occurrence of the Haiyuan strong earthquake is not only related to tectonic activities,but also to lithologic characters of the region.     

Re-discussion on the Jiaochang Arcuate Structure, Sichuan Province, and the Seismogenic Structure for Diexi Earthquake in 19331

The Jiaocbang arcuate structure is one of the numerous arcuate structural belts in Sichuan. The present paper gives a further argument about the characteristics of that arcuate structure and the new activity of the Songpinggou fault and affirms that the Songpinggou fault is an active fault in the Holocene epoch. The Diexi M7.5 earthquake took place in 1933 on the west wing of that arcuate structure, near the apex of the arc. Many authors have given quite different opinions about the genetic structure of that earthquake. The authors have made on-the-spot investigations time and again over recent years. Besides this, the authors have also further studied the shape of intensity contour lines, the distribution characteristics of ground surface seismic hazards, the left-lateral dislocation of buildings along the Songpinggou fault, the NWtrending ground fissures that developed on the ground surface after earthquake, and so on. On this basis, it is still considered that the seismogenic fault of the 1933 Diexi M7.5 earthquake was the Songpinggou fault on the west wing of the Jiaochang arcuate structure.     

略阳煎茶岭铜镍硫化物矿床Re—Os同位素年龄及其地质意义

采用矿石Re-Os同位素方法对陕西省煎茶岭硫化镍矿床矿石进行了成矿年代学研究,获得了878士27 Ma(1σ)的等时线年龄,首次厘定了该矿床成矿时代为新元古代,成岩成矿基本同时.通过对878 Ma硫化镍矿石初始Re-Os同位素体系的γOs计算和Re/Os值分析表明,其yOs和Re/Os值变化范围大,深部条带状矿石的Re/Os值仅为0.05,yOs为-6.70;块状矿石的Re/Os值范围为4.24～24.43,γOs为-15.37～+280.65,说明成矿过程中有壳源物质的混染;两件样品的γOs为负值(-15.37,-6.70),可能指示其超镁铁质岩浆来源于Re亏损地幔.煎茶岭超基性岩体年龄及其镍矿石的Re-Os等时线年龄与扬子克拉通北缘火山岩浆活动时间相对应,它们是扬子克拉通西北缘晋宁期构造岩浆成矿作用的产物.     

川滇地区成组强震活动的有序步进特征

研究了川滇主要地震构造带历史成组强震和现今小震的空间-时间活动图像.分析结果:在垂直断层走向两侧约30km范围内的强震活动,在北西、南北、北东走向的构造带间相继交替发生,存在有序步进的联动现象.这可能也是川滇成组强震活动的一个基本特点,且现今小震活动亦呈现此特点.最后对此现象概述了目前力学机理方面的初步认识.     

浙江省测绘学会评选学会工作先进集体和先进个人办法

为增强学会的凝聚力，鼓励先进、表彰和奖励在学会活动中涌现出的学会工作先进集体和先进个人，特制定本办法。     

影响惠州的一次寒露风过程

1992年9－10月，由于冷空气不断爆发南下，致使各地先后出现降温。10月4日和11日冷空气两次南侵本省，副高明显减弱，加上空气干燥并伴有3级以上的偏北风，我市从12日开始出现了长达9天的干冷型寒露风天气过程，对晚稻的抽穗扬花有严重影响。本文对这次寒露风天气过程进行分析。1寒露风过程的冷空气活动1992年10月份内，共有3次冷空气活动，分别出现在上旬中期、中旬前期和下旬前期。就强度而言，除上旬中期的冷空气活动达到了中等强度以外，其余2次均为弱冷空气。1．1上旬中期的冷空气过程上旬中期的冷空气活动主要影响我国北部和东部地区…     

宜昌市火灾活动规律及防治对策

分析宜昌市城区１９７０－１９９４年发生的火灾个例，揭示城市火灾的若干特点，提出相应的防治对策。     

由1990年12月希腊北部VAN台记录的电活动所做的错误警报

１９９１年１月６日法国报纸“Ｌｅ Ｍｏｎｄｅ”和１９９１年１月８日－１０日希脂报纸及电台，都发布了ＶＡＮ地震预报。根据Ｖａｒｏｔｓｏｓ教授寄给希腊公共工作部部长的一封信，并考虑了ＶＡＮ以前的出版物以及预报地区最近的地震数据，我们评价了此次预报。     

一些强余震前余震活动的前兆性平静和恢复

定量地分析了日本若干Ｍ≥７的浅源强震后的余震活动的时间特征。这些强震后都伴有强余震的发生，而且这些强余震又都触发了自身的余震活动。本研究的目的在考察这种强余震发生前的余震活动的任何异常变化，在强余震发生之疹，余震活动明显代于由修订的大森公式所得的期望值。     

云南地区1995～1996年三次强震爆发的共性研究

论述了在１９９５～１９９６年云南地区发生的孟连西南７．３级，武定６．５级和丽江７．０级３次强烈地震的孕育过程中，近源区中小地震的异常增频特点和临震前大气压力的突变共性，并据此提出，强震的发生乃是地壳内外力涨落地加剧的结果。