地震预测预报经验的积累

根据《中国震例》所载1966年至1985年以来，全国Ms≥5.0的58次中强地震的《震例》研究成果，从应用的角度出发，探讨了动态跟踪预测未来中强地震活动“时”、“空”、“强”的活动规律，得出如下启示1)利用地震的前兆总体演变过程的阶段性以探讨定量预测其“活动时段”；2)利用地震的前兆总体分布图象以探讨定量预测其“活动空间”；3)利用地震的前兆环的规模以粗略地预估其未来强震的“活动强度”。还初步探讨了利用它们的“场”、“源”演变的关联性，提出文中一些作法的物理意义之所在。     

地震预测预报经验的积累—谈《中国震例》的实际应用

根据《中国震例》所载1966年至1985年以来，全国Ms≥5．0的58次中强地震的《震例》研究成果，从应用的角度出发，探讨了动态跟踪预测未来中强地震活动“时”、“空”、“强”的活动规律，得出如下启示：1）利用地震的前兆总体演变过程的阶段性以探讨定量预测其“活动时段”；2）利用地震的前兆总体分布图象以探讨定量预测其“活动空间”；3）利用地震的前兆环的规模以粗略地预估其未来强震的“活动强度”。还初步探讨了利用它们的“场”、“源”演变的关联性，提出文中一些作法的物理意义之所在。     

荒漠化——土地的“伤痛”

过去我们常常把土地荒漠化理解为是“沙漠不断扩大,把沙漠里的沙子扩散到越来越广的肥沃土地上去”。然而事实上荒漠化不只如此,1992年世界环境与发展大会上确定了荒漠化是“包括气候和人类活动在内种种因素造成的干旱、半干旱和亚湿润地区的土地退化”。也就是由于大风吹蚀,流水侵蚀,土壤盐渍化等造成的土壤生产力下降或丧失,都称为荒漠化。有时也将湿润和亚湿润区的石漠化归入荒漠化范畴。     

全球及中国大陆强震时序活动特征

基于强震目录,讨论了全球、中国大陆西部及周边“大三角地区”和中国大陆地区强震活动时序特征。依据8级地震分段活动特征分析认为,20世纪60年代前后全球特大地震活动状态存在显著差异;利用最优分割统计分析认为,自1800年以来“大三角地区”经历了持续时间为100余年的8级地震活动过程;进一步分析认为全球和“大三角”地区强震活动可能具有至少百年尺度的地震“周期”,而且具有一定的准同步性。中国大陆地区MS≥7.0浅源地震活动明显受控于“大三角”地区和全球更大空间尺度的地震活动,地震活动时序上表现为十几年和近百年不同时间层次上的活动特征。     

自然破裂与地震的整体观

地震处在自然破裂系列广阔的背景中。为了在此背景中研究人们十分关注的地震问题,本文首先对全球、全国、大华北、唐山地区四种尺度下的地震资料进行频度—震级统计。在此基础上,引入广义b值概念。然后,分别从地震分维的整体观、地震过程的整体观和地震预测的整体观等方面进行了讨论,引出有内涵的F值,并指出地震整体观的哲学基础。最后,在自然界破裂现象整体观的指导下,提出为首都地震圈在矿山建立应力监测哨的设想。     

地球系统科学与社会可持续发展--青年科学家论坛第76次活动

由中国科学技术协会主办的“青年科学家论坛”第 76次活动于 2 0 0 3年 8月 2 1～ 2 2日在北京中国科技会堂举行。活动的主题是“地球系统科学与社会可持续发展”。 4 2位来自全国各地的青年科学家和研究生参加了此次活动 ,代表中包括多位“中国青年科技奖”获得者 ,中国科学院“百人计划”、国家“百千万人才工程”等的入选者 ,以及“国家杰出青年科学基金”项目、国家“86 3项目”、国家“973项目”的项目或课题负责人。中国科学技术协会学术部部长、“青年科学家论坛”活动组委会常务副主任马阳出席了论坛活动。这次活动得到国际科联环境…     

中国大陆与周边板块边界强震活动的互动关系探讨

分析中国大陆与周边板块边界、尤其是西部地震“大三角”地区强震活动的关系认为,中国大陆与周边板块边界带的强震活动之间存在互动关系,而不完全是后者对前者的触发作用。进而根据中国大陆地震构造环境、大尺度地壳运动变形动态与强震活动状况,研究和探讨了这种“互动关系”可能的构造动力机理和我国大陆未来地震活动的发展趋势。     

试析川西地区地震“空区”与活动背景

本文给出了1967～1982年川西地区17次小震活动“空区”,对“空区”分布的时、空特征进行了分析,认为“空区”的出现与区域地震活动背景有关。     

1985年9月墨西哥8.2级地震与哈雷彗星

1985年9月19日墨西哥8.2级地震(根据中国地震台网测定)对墨西哥城造成了严重破坏,伤亡数万人,是八十年代以来破坏最为严重的大地震之一,可能标志了全球地震活动的一个重要转折时期的开始。它的发生时间恰好在1986年哈雷彗星来到地球附近约1年前,特就此进行探讨。笔者曾在拙作《哈雷彗星接近地球与大地震关系的初步探讨》一文(刊登在《国际地震动态》1981年第7期)中明确提出,“哈雷彗星与大地震可能存在着一定的联系”,“从哈雷彗星与大地震对应关系看,八十年代前半期有可能是地震活动升高时期,尤应注意对中国西部强震的监视”。高建国、郭履灿对此作了     

“川滇菱块”东部边界的强震活动

本文探讨了西南地区“川滇菱块”东部边界的强震活动情况。研究表明,“川滇菱块”东部边界强震活动在西南地区最为强烈。它集中了川滇地区全部７．６级以上地震,历史强震活动有较明显的活跃期和平静期,且呈现某种自然节律,７级地震显示较好的南北迁移规律,强震时间分布遵从幂函数特征。     

以全球观点推进和参与地震科学研究

叙述了地震科学的发展和与地震科学发展有关的问题,提出了在现今地震科学发展的形势下,地震科研人员和管理人员应密切关注的主要问题,指出了科研人员和管理人员的视野应朝何方面扩展和延伸,得出地球科学的研究必须以全球观点予以推进和参与才有出路的结论。     

地磁场K变化的信息熵

K指数作为最常用的一种地磁活动指数,它描述的是地磁场不规则变化的扰动程度,因此,地磁场的不规则变化又称为K变化.K指数虽已有70多年的历史,并在世界范围内被普遍接受,然而,它只能反映扰动的幅度,无法反映扰动的次数,只标定扰动幅度最大的分量,无法给出地磁场三分量扰动的总体描述,同时,K指数的标定还与坐标选择有关.从信息科...     

The Planning,Organization and Management of Post-disaster Reconstruction of the Lushan Earthquake Based on the Local as the Main Body

A new organization and management mechanism with the local government as the main body was created during the post-disaster reconstruction of the "4. 20 " Lushan earthquake,in which the experiences and lessons were drawn from the "5. 12"Wenchuan earthquake. Correspondingly, the local government conducted an exploration of the organization and management mode in the field of planning and construction. The effective experiences have been accumulated, including working out a full coverage planning,taking the leading part in the urban-rural planning,and exercising whole space control over the disaster area. An innovation management mode named as "Five Generals Pattern"was implemented in the construction projects. In view that the rural housing reconstruction was a weak link, a new approach to improving the construction management was investigated,by means of strengthening on-site supervision,establishing a technical platform,and bolstering public participation.     

Lateral variation of Rayleigh wave dispersion character Part III: Atlantic Ocean,Africa and Indian Ocean

Summary In continuation of Part II, investigations of the lateral variation of group velocity dispersion character of Rayleigh waves were carried out for the Atlantic and Indian Oceans and for Africa. Maximum group velocity at such short periods as 25 to 30 seconds is observed in the Mid-Atlantic Ridge, in agreement with earlier observations from the East Pacific Rise, but was not observed for the Indian Rise. Less continental dispersion regions are found in Africa and in the whole of the Arabian Peninsula. Eastern half of the Indian Ocean seems to have a typical oceanic crustal structure. The dispersion patterns were checked in every area by earlier data. All results so far obtained by the present author on the lateral variation of dispersion characteristics have been compiled into a world map.     

欧亚地震带地震活动增强与中国大陆地区7级以上地震发生的关系分析

根据欧亚地震带7级以上地震释放能量与全球7级以上地震释放总能量之比,利用χ²检验方法对欧亚地震带地震活动增强与中国大陆地区7级以上地震发生的关系进行了统计检验。结果表明,当出现欧亚带年地震释放能量比高于50%且有8级以上地震发生时,其后3年内中国大陆地区将有发生多次7级以上地震或8级地震的可能性,这个关系在10%的显著水平下通过显著性检验。     

我国环境问题与环境地球物理学

从环境和环境问题出发，简述了环境地球物理学的形成过程，并定义环境地球物理学为：应用地球物理学的理论和方法，研究解决环境保护、改善和治理方面问题的一门地球物理分支学科．文章叙述了全球和我国当前的主要环境问题，论述了环境地球物理学在解决这些问题中所起的重要作用；介绍了我国环境地球物理学在研究解决某些环境问题中的应用事例；并在分析我国对环境地球物理的需求以及满足这种需求的能力之后指出，我国环境地球物理工作者必将为我国和世界环境问题的解决及学科的发展做出应有的贡献．     

《系列世界地图》及其应用与推广

《系列世界地图》是本世纪初诞生在我国的创新性地图作品，该图以东、西、南、北四种视角，从经度、纬度两种方向，准确地将世界地理和中国与世界的地理关系完整地展现在读者面前.本文回顾了新编《系列世界地图》的研制过程和基本概况，给出了近几年《系列世界地图》在国家科考、国防科研和地学研究中的应用事例，介绍了《系列世界地图》的普及和推广情况.     

What Do Data Used to Develop Ground-Motion Prediction Equations Tell Us About Motions Near Faults?

A large database of ground motions from shallow earthquakes occurring in active tectonic regions around the world, recently developed in the Pacific Earthquake Engineering Center’s NGA-West2 project, has been used to investigate what such a database can say about the properties and processes of crustal fault zones. There are a relatively small number of near-rupture records, implying that few recordings in the database are within crustal fault zones, but the records that do exist emphasize the complexity of ground-motion amplitudes and polarization close to individual faults. On average over the whole data set, however, the scaling of ground motions with magnitude at a fixed distance, and the distance dependence of the ground motions, seem to be largely consistent with simple seismological models of source scaling, path propagation effects, and local site amplification. The data show that ground motions close to large faults, as measured by elastic response spectra, tend to saturate and become essentially constant for short periods. This saturation seems to be primarily a geometrical effect, due to the increasing size of the rupture surface with magnitude, and not due to a breakdown in self similarity.     

Découverte de coulées pyroclastiques sous-marines dans la zone de l’Iran Central — Mécanisme de mise en place

Study of these submarine pyroclastic flows is important for two reasons:

1. From a regional point of view, submarine pyroclastic flows partially explain the origin of widespread argillized glasses in the Eocene sedimentary series of Central Iran, which have diversely been described by earlier workers as Green Tuffs, Tuffaceous Muds, Green Series.
2. More generally, in contrast to basaltic volcanism, submarine acid volcanism is still very poorly-known. The mechanism here proposed is as follows: starting with a submarine, highly vesiculated lava containing idiomorphic phenocrysts, gas expansion gives rise to a vitroclastic shardy facies, whereas phenocrysts are fragmented. The whole makes up a gravitational flow that is rich in pumice, glassy shards, broken crystals, and gases; it becomes increasingly turbulent and able to tear-up sea-bottom sediments in its down-stream course. This flow evolves into turbidity currents at its distal reaches.

     

A look at global seismicity during 1999 in the longer-term time frame

An analysis and discussion of the main features and effects of the 1999global seismicity based especially on the inferred patterns of strong(M_w 7) earthquakes using NEIC/USGS data is presented.Based on the above data and their statistical features (see also Table 1)one may state that from the point of view of occurrence rate (number/yr)the 1999 global seismicity was fairly regular, but from the moment (orenergy) release standpoint it is well under the long-term average. The spacepartition was again rather typical and time distribution was quasi-Poissonian,noteworthy, the 1999 worldwide seismicity had an anomalously high deathtoll, to be discussed later. Two main new insights are brought by ouranalysis: (i) a (mega)quiescence along the whole south American segmentof circum-Pacific earthquake belt, which was inferred and rated asanomalous while it was underway and which, in retrospect, ended with thegreat (M_w = 8.4 HRV) 2001 Arequipa (Peru) event; (ii) an intriguingmonotonous rate decrease within only magnitude class 5.0 to 5.9 duringthe analyzed period (i.e., 1990–1999).