豫01井水位异常与地震的关系分析

针对2018年青海德令哈台尕海井水位破年变异常,系统梳理和分析该井相关资料,发现该井两套水位仪运行稳定、数据一致性非常好,而这段时期异常与降雨和气压不相关,以及井孔附近地区的视应力值较高,表明该地区地壳应力水平进一步增强。利用水位变幅、去趋势和一阶差分分析,结果显示,该项异常信度较高,反映该区域构造活动信息,是周边两次中等强度地震的共同前兆,属于中短期异常。     

云南地震前兆与短临预报

在云南地区近３０年前兆观测及其地震预测预报研究与实践的基础上,从映震效能的角度对云南地区的前兆观测进行了一次系统研究,从６４个前兆台站１６８个观测 ,优选出了２０个具有较好映震效能的前兆台项。它们初步构成对云南地区地震进行”时、空、强“预测的骨干前兆指标群。     

震情过程追踪与发震时间的综合概率预报

基于大震前主破裂潜在变化的过程中产生出小震活动、地壳形变异常以及伴随地壳形变而产生出的地下水、水化学、地电阻率等前兆现象随时间变化显示出的动态异常图象,依据河北省及周围地区１９７０年至１９８８年的中强震前的前兆异常资料的研究,提取出了９个前兆异常因子的异常变化规律及特征,并建立了务因子的概率预报模型,同时计算出相应的前兆发生后不同时段内地震发生的概率。最后在多个因子随时间推移而逐次出现前兆异常的情     

苏鲁交界及南黄海地区地震波速比的变化特征

本文主要应用多台波速比和单台波速比的方法，计算了苏鲁交界及南黄海（北纬３５°３５′至３６°００′，东经１１７°００′至１２１°００′）范围内，１９８４到１９９１年７月发生在该区域的１６３次ＭＬ≥１．７地震的波速比值，并对波速比结果进行ｔ检验和模糊数学分析识别。分析结果发现，１９８５年１月至１１月出现了不连续的波速比低值异常时段，模糊数学识别的异常从属函数在这段时间也呈现高值。异常恢复后，１９８７年     

马边地震带发震构造背景的初步研究

北北西向的马边－盐津隐伏深断裂是马边地震带形成的主要条件，尤其被东西向甘洛－沐川深断裂和盐津－叙永深断裂转限的段落是强震多发段。地壳表层有北北西向马边－盐津断裂组和地面微隆起带，但地表断裂与陷伏深断裂并不连通，且地表断裂走向与结构复杂多变，这是造成马边地震带强震地面破坏效应及地震影响场特点的基本原因。     

华北地区重力场与沉积层构造

位于中朝准地台的华北地区是由几个不同的断块组成的,重力异常场的分布具有很强的浅部效应、块状分布和深浅叠加场的特点。重力的高程效应很复杂,不同波长的起伏变化有不同的影响系数。本文对布格改正的有关问题进行了讨论,指出华北如区表浅层的密度值偏低（2520kg/m3）,该区合理的布格改正公式为△g2=-0.0879H。将重力场的垂直导数和向上延拓结合起来,有利于揭示地壳上部构造特征。本文搜集整理了由第四系到寒武系的沉积层资料,给出了沉积层总厚度和视密度的分布。对深部重力异常的分析表明,华北沉积层的形成有深源性质,在均衡调节中起着一定的内载荷作用。     

黔江台水管仪与垂直摆预报效能对比分析

水管仪与垂直摆均是通过观测地倾斜变化来捕捉地震前兆信息的定点形变仪器,但因工作原理和观测频段不同,其观测结果和异常形态具有一定差异性。因此,对两种仪器的不同异常形态进行预报效能评估具有重要意义。利用异常自动化处理软件,提取黔江台倾斜仪各测项趋势转折、速率变化、破年变和潮汐因子等常见异常,并结合区域范围内的地震,对不同异常进行R值评分,评估不同测项的预报效能。结果显示：垂直摆NS分量预报效能最高,其趋势转折异常和M2潮汐因子异常均具有较好的预报指示意义;两套仪器的EW分量分别在破年变和速率变化预报效能较高;而水管仪NS分量预报效能最差,可能与该测项仪器故障频繁有关。此外,不同测项的异常对应的地震分布也具有一定的规律性。     

Long‐term landscape evolution: linking tectonics and surface processes

Research in landscape evolution over millions to tens of millions of years slowed considerably in the mid‐20th century, when Davisian and other approaches to geomorphology were replaced by functional, morphometric and ultimately process‐based approaches. Hack's scheme of dynamic equilibrium in landscape evolution was perhaps the major theoretical contribution to long‐term landscape evolution between the 1950s and about 1990, but it essentially ‘looked back’ to Davis for its springboard to a viewpoint contrary to that of Davis, as did less widely known schemes, such as Crickmay's hypothesis of unequal activity. Since about 1990, the field of long‐term landscape evolution has blossomed again, stimulated by the plate tectonics revolution and its re‐forging of the link between tectonics and topography, and by the development of numerical models that explore the links between tectonic processes and surface processes. This numerical modelling of landscape evolution has been built around formulation of bedrock river processes and slope processes, and has mostly focused on high‐elevation passive continental margins and convergent zones; these models now routinely include flexural and denudational isostasy. Major breakthroughs in analytical and geochronological techniques have been of profound relevance to all of the above. Low‐temperature thermochronology, and in particular apatite fission track analysis and (U–Th)/He analysis in apatite, have enabled rates of rock uplift and denudational exhumation from relatively shallow crustal depths (up to about 4 km) to be determined directly from, in effect, rock hand specimens. In a few situations, (U–Th)/He analysis has been used to determine the antiquity of major, long‐wavelength topography. Cosmogenic isotope analysis has enabled the determination of the ‘ages’ of bedrock and sedimentary surfaces, and/or the rates of denudation of these surfaces. These latter advances represent in some ways a ‘holy grail’ in geomorphology in that they enable determination of ‘dates and rates’ of geomorphological processes directly from rock surfaces. The increasing availability of analytical techniques such as cosmogenic isotope analysis should mean that much larger data sets become possible and lead to more sophisticated analyses, such as probability density functions (PDFs) of cosmogenic ages and even of cosmogenic isotope concentrations (CICs). PDFs of isotope concentrations must be a function of catchment area geomorphology (including tectonics) and it is at least theoretically possible to infer aspects of source area geomorphology and geomorphological processes from PDFs of CICs in sediments (‘detrital CICs’). Thus it may be possible to use PDFs of detrital CICs in basin sediments as a tool to infer aspects of the sediments' source area geomorphology and tectonics, complementing the standard sedimentological textural and compositional approaches to such issues. One of the most stimulating of recent conceptual advances has followed the considerations of the relationships between tectonics, climate and surface processes and especially the recognition of the importance of denudational isostasy in driving rock uplift (i.e. in driving tectonics and crustal processes). Attention has been focused very directly on surface processes and on the ways in which they may ‘drive’ rock uplift and thus even influence sub‐surface crustal conditions, such as pressure and temperature. Consequently, the broader geoscience communities are looking to geomorphologists to provide more detailed information on rates and processes of bedrock channel incision, as well as on catchment responses to such bedrock channel processes. More sophisticated numerical models of processes in bedrock channels and on their flanking hillslopes are required. In current numerical models of long‐term evolution of hillslopes and interfluves, for example, the simple dependency on slope of both the fluvial and hillslope components of these models means that a Davisian‐type of landscape evolution characterized by slope lowering is inevitably ‘confirmed’ by the models. In numerical modelling, the next advances will require better parameterized algorithms for hillslope processes, and more sophisticated formulations of bedrock channel incision processes, incorporating, for example, the effects of sediment shielding of the bed. Such increasing sophistication must be matched by careful assessment and testing of model outputs using pre‐established criteria and tests. Confirmation by these more sophisticated Davisian‐type numerical models of slope lowering under conditions of tectonic stability (no active rock uplift), and of constant slope angle and steady‐state landscape under conditions of ongoing rock uplift, will indicate that the Davis and Hack models are not mutually exclusive. A Hack‐type model (or a variant of it, incorporating slope adjustment to rock strength rather than to regolith strength) will apply to active settings where there is sufficient stream power and/or sediment flux for channels to incise at the rate of rock uplift. Post‐orogenic settings of decreased (or zero) active rock uplift would be characterized by a Davisian scheme of declining slope angles and non‐steady‐state (or transient) landscapes. Such post‐orogenic landscapes deserve much more attention than they have received of late, not least because the intriguing questions they pose about the preservation of ancient landscapes were hinted at in passing in the 1960s and have recently re‐surfaced. As we begin to ask again some of the grand questions that lay at the heart of geomorphology in its earliest days, large‐scale geomorphology is on the threshold of another ‘golden’ era to match that of the first half of the 20th century, when cyclical approaches underpinned virtually all geomorphological work. Copyright © 2007 John Wiley & Sons, Ltd.     

云南彝良“9?7地震”前异常特点

对2012年9月7日云南省昭通市彝良县洛泽河一带5.7、5.6级地震前地震活动和前兆异常分析,其地震活动特征、流体和形变动态变化及预测指标,发现：地震前4级地震活动水平增强、出现小震活动空区;前兆异常开始于震前1年左右;短期异常有由外围向震中迁移的现象;临震异常出现的时间较为集中,震前一周内。对该地区5.0级以上强震的预报和研究具有一定的指示意义。     

位场曲化平的插值-迭代法

将起伏曲面B上的位场向下延拓至曲面最低点的平面A的插值-迭代法步骤是：1）将曲面B上的场值放置在水平面A上具有相同水平坐标的点上,作为A上的初值;2）用若干水平面切割B,从A的初值,用快速傅里叶变换法(FFT)向上延拓出这些平面的场值,用插值的方法从这些平面的场值计算曲面B的场值;3）根据B上的实测值与计算值的差值,对A上的值进行加权改正;4）重复步骤2）和3）,直到B上的差值小到可以忽略.这种插值-迭代法具有高的计算速度,比通常的FFT法延拓得更深,可以超过10倍点距.文中给出计算实例.