新疆境内各相邻区域地震活动相关性分析

新疆地震活动分布区域广,主要分布在南北天山、西昆仑、阿尔泰、阿尔金山与塔里木盆地和准噶尔盆地的衔接地带。各地震带地震活动水平不尽相同,其中南天山与北天山地震带以及帕米尔一西昆仑地震带的地震活动水平较高,地震活动呈西强东弱的特点。自2011年以来新疆境内地震活动呈现出5级地震连发,6级地震活动频繁,且各地震带均有分布的特点。利用新疆历史地震目录,分析新疆境内各片区发生地震活动是否具有相关性,并从中获得各片区地震活动相关性的量度,以此可以将这些量度作为新疆境内各片区地震中长期预报的辅助性分析方法。     

Generalization of PhaseNet in Shandong and its application to the Changqing M4.1 earthquake sequence

Waveforms of seismic events, extracted from January 2019 to December 2021 were used to construct a test dataset to investigate the generalizability of PhaseNet in the Shandong region. The results show that errors in the picking of seismic phases(P-and S-waves) had a broadly normal distribution, mainly concentrated in the ranges of-0.4–0.3 s and-0.4–0.8 s, respectively. These results were compared with those published in the original PhaseNet article and were found to be approximately 0.2–0.4 s l...     

Seismic history and consistent seismicity: Evidence from southern Italy

In this paper a method is proposed to evaluate the seismicity level of an area in a given historical period, based on records of seismic events, source characteristics and intensity attenuation with distance. Also considered is the seismic activity recorded in southern Italy during the 10th and 11th centuries, seismic records being obtained from all available sources. To determine the level of seismicity, a key role is played by source characteristics, i.e. recording modalities and activity periods of recording centers. In addition, models of intensity attenuation with distance allow the assessment of the size of the area under investigation. This paper identifies the areas, in the 10th and 11th centuries, where major earthquakes (M 6.5) did not occur during periods of silence of sources, as well as those where such events cannot be excluded. For each area, different levels of probability were determined by applying the Cox linear logistic model to historical seismic data. The completeness analysis, in terms of area and time-span coverage, is a valuable tool to assess seismicity in seismogenetic areas. The reproducibility of the model for lower magnitude earthquakes (M < 6.5) is reliable.     

Explaining the physical origin of Båth's law

Båth's law is one of the three well-known scaling laws for earthquakes. It states that the difference in magnitudes of the mainshock and its largest aftershock is approximately constant, independent of the magnitude of the mainshock. Despite the progress in understanding the nature of Båth's law, the question of whether this law has a physical basis, or is simply a consequence of basic statistical features of aftershock sequences, has remained controversial. In this article we show that Båth's law can be derived within the Cosserat continuum theory from equations describing fault interaction. Our equations can describe both (1) the interacting mainshocks and aftershocks, and (2) the interacting foreshocks and mainshocks. We also derive (1) spatial extension of Båth's law to the normalized distance between the locations of the interacting mainshocks and aftershocks (or foreshocks and mainshocks), and (2) temporal extension of Båth's law to the difference between the time of the interacting mainshocks and aftershocks (or foreshocks and mainshocks).     

基于B/S的地质资料信息集群化技术研究

通过探索福建省地质资料信息服务集群化与产业化试点研究,总结福建省平潭综合实验区地质资料汇交与服务的技术流程,基于B/S集成环境,融合了Web、DHTML、Mi-crosoft IIS和.Net等技术,设计并实现了面向多层次用户快速查询地质资料信息目录查询服务,发挥地质成果资料的价值,为推进全省“两化”工作提供借鉴与参考.     

山东地区最小完整性震级的确定——R-S检验

介绍了估计最小完整性震级MC的Rydelek-Sacks检验法,选取山东各个震情追踪区作为研究区域,使用1970年以来山东地区的地震目录,采用该方法以及与其他方法的综合分析,确定了其最小完整性震级:沂沭地区2.4级,鲁西地区2.0级,鲁东地区2.8级,最后对该方法的优点以及在应用中存在的问题进行了总结和讨论.     

中美两国全球6级以上地震目录对比分析

中国地震台网中心(CENC)和美国国家地震信息中心(NEIC)提供的全球地震目录经常出现较大偏差.CENC发震时刻较早,CENC震源深度较深.2001年至2010年全球6.0级以上地震约11.67％存在明显目录偏差,印度洋板块北侧集中约70％有各类偏差地震.印度洋板块北侧各项误差统计占全世界同类地震约70％,表现出较好的一致性.这种现象应与震源过程有关,与该地区S波走时异常问题耦合,而不是算法或随机误差造成的.     

钻孔应变台站记震能力研究

以昌平台体应变为例,研究了体现钻孔应变台站记震能力的方法,并对计算步骤和处理方法进行了说明.选取20套中国大陆观测时间较长且数据较好的钻孔体应变仪观测记录作为研究对象,计算出其各自的记震能力线,给出各台对6级地震的响应范围.此公式不仅可以量化钻孔应变仪的对地震的反应能力,而且是对地震仪器的一种新的科学评估方法.同时,基于地震前兆释放能量小于地震发生时释放的能量的基本理解,此结果对于确定地震前兆的位置和震级范围也有参考价值.     

Comparison of two earthquake early warning location methods

According to earthquake catalog records of Fujian Seismic Network, the T _now method and the four-station continuous location method put forward by Jin Xing are inspected by using P-wave arrival information of the first four stations in each earthquake. It shows that the four-station continuous location method can locate more seismic events than the T _now method. By analyzing the results, it is concluded that the reason for this is that the T _now method makes use of information from stations without being triggered, while some stations failed to be reflected in earthquake catalog because of discontinuous records or unclear records of seismic phases. For seismic events whose location results can be given, there is no obvious difference in location results of the two methods and positioning deviation of most seismic events is also not significant. For earthquakes outside the network, the positioning deviation may amplify as the epicentral distance enlarges, which may relate to the situation that the seismic stations are centered on one side of epicenter and the opening angle between seismic stations used for location and epicenter is small.     

地震快报目录自动网上发布软件QCAT的开发与应用

地震快报目录是国家数字地震台网分中心数据服务的重要组成部分之一,为了能够更好地提供服务,我们使用Perl语言,开发了地震快报目录自动网上发布软件QCAT。本文分析了QCAT软件开发的应用需求,阐明了软件的设计思路,描述了软件的功能和结构,并对QCAT软件的各个模块进行了详细介绍,最终对应用QCAT之后,用户访问快报目录的方法做了说明。