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1.
Liu Pu-xiong Zheng Da-lin Che Shi Pan Huai-wen Liu Gui-ping Yang Li-ming 《地震学报(英文版)》2003,16(2):219-225
A great earthquake of M
S=8.1 took place in the west of Kunlun Pass on November 14, 2001. The epicenter is located at 36.2°N and 90.9°E. The analysis
shows that some main precursory seismic patterns appear before the great earthquake, e.g., seismic gap, seismic band, increased activity, seismicity quiet and swarm activity. The evolution of the seismic patterns
before the earthquake of M
S=8.1 exhibits a course very similar to that found for earthquake cases with M
S≥7. The difference is that anomalous seismicity before the earthquake of M
S=8.1 involves in the larger area coverage and higher seismic magnitude. This provides an evidence for recognizing precursor
and forecasting of very large earthquake. Finally, we review the rough prediction of the great earthquake and discuss some
problems related to the prediction of great earthquakes. 相似文献
2.
对意大利国家强震台网在2016年8月24日获得的其中部拉齐奥大区阿库莫利市发生的MW6.2地震强震动三分向记录进行处理和分析。完成原始数据基线校正、滤波等基本数据处理,回归此次地震动幅值衰减规律,发现其整体与ITA08及BA08的衰减趋势一致,但远场实际值低于预测值,不同场地条件下的衰减特性与ITA10一致,近震源幅值较大,且方向性明显;计算并回归分析几种持时,与全球经验预测方程均基本吻合;比较4个幅值较大的近震源台站的反应谱,发现其明显高于欧洲抗震设计规范中的设计反应谱。结合此次震害特点,该地区在实际建设中仍需提高抗震设防能力,以确保安全性等级。 相似文献
3.
地震地下流体在地震预测研究与震情跟踪方面发挥着重要作用,本文对2021年5月22日青海玛多MS7.4地震前震中附近地下流体观测资料及异常特征进行系统分析,并结合震前预测过程进行了回顾性总结。结果表明,玛多MS7.4地震震中距500km范围内存在5项异常,其中4项为短期异常,主要出现在震前2～3个月。异常在空间上分布不均匀,主要位于玛多MS7.4地震震中的东北部和西南部,整体呈现出由外围向震中收缩的迁移特征,且玛多MS7.4地震和2010年青海玉树MS7.1地震在异常特征和应力加载作用方面具有较好的相似性。研究结果为地震监测能力较低地区积累了震例资料,对于提升强震地下流体前兆异常认识及未来震情趋势判定水平具有一定的参考意义。 相似文献
4.
Most of the present earthquake early warning systems are based on broadband or strong motion recordings. How-ever, the short-period instruments are still deployed. It is well-known that short-period recordings have saturation problems for large earthquakes when estimating the size of an earthquake. Thus, it is necessary to make clear the magnitude at which saturation starts to occur for the commonly used τc and Pd measurements, respectively. To investigate the possibility of using short-period seismic recordings for earthquake early warning, we conducted a simulated experiment using the strong motion data of the 1999 Chi-Chi earthquake sequence including its main shock and 31 aftershocks, with magnitude span from 4 to 7.6. The strong motion acceleration recordings were convolved with the instrument response of short-period seismographs in northern China to simulate short-period seismograms. Parameters τc and Pd from the first-three-second seismograms were calculated for the simulated short-period recordings and compared with that obtained by the original strong ground motion recordings. The result showed that to some extent, short-period recordings can be used for threshold earthquake early warning, while the magnitude saturation of Pd estimation can be up to 6.5, better than τc estimation. 相似文献
5.
在中国地震台网中心2016年底利用热红外遥感技术预测2017年新疆西部地区为潜在MS 6.6±0.2地震危险区的基础上,分析2017年8月9日精河MS6.6地震临震时段引潮力变化,并选用18时（UTC）中国大陆近地表50m高度处的遥感大气温度数据,以震前引潮力值最高点时刻（8月1日）为时间背景,获取地震前后（8月2~13日）连续的大气温度日增量分布图像,跟踪分析精河MS6.6地震短临大气温度变化。结果显示：地震发生在天体引潮力由高峰—低谷连续周期变化的低谷时段,而大气温度变化过程显示,在全国大范围内,仅震中附近大气温度升高明显,其异常演化经历了起始—加强—高峰—衰减—再增强—发震—平静的动态过程。增温过程与潮汐变化具有同步性,这表明引潮力对本次地震具有触诱发的作用,而大气温度变化反映了本次地震地应力的变化过程,也说明在地震预测实践中,从中、短临多时间尺度综合分析遥感大气温度和引潮力变化,将有助于提高地震预测能力。 相似文献
6.
以中国静止气象卫星FY-2C/2E红外遥感资料为依据,采用小波变换与功率谱相对变化法对2014年10月7日云南景谷MS6.6地震进行震例数据处理和分析。结果显示:震前热异常具有明显时空特征,2014年8月上旬震中及其周围区域出现热红外异常,异常区范围随时间逐渐扩大、幅度陡增;8月30日左右异常面积达到最大,异常持续时间近一个月,异常幅度最大值达到平均值的14倍多,最大值45天后发生地震;该次地震热红外异常特征显著,容易识别,可作为一种识别地震热异常信息的判据,进一步验证卫星热红外异常在地震预判方面的作用。 相似文献
7.
以2017年3月27日漾濞5.1级地震为例,根据区域特性和信噪比要求,选取数据较为完整的6个台站记录的2017年1月1日～6月6日期间的宾川地震信号发射台气枪震源波形资料,采用互相关检测技术提取6个台站各自稳定震相的走时数据,并对漾濞5.1级地震前后走时数据的变化情况进行分析。结果表明,漾濞5.1级地震前后6个台站各自稳定震相存在较为明显的走时变化,且短期内走时变化具有较好的同步性,相关台站异常幅度大小和异常出现时间存在细小差异。地震发生前,6个台站走时低值异常过程明显,以YUL台最为显著。地震发生前后走时变化形态特征为双“V”型,漾濞5.1级地震发生在第1个“V”型末端。地震发生后,不同方位相关台站受地震的影响程度不同,走时波动大小存在差异。 相似文献
8.
This paper systematically summarized the relation of the abnormal change of He and H2 dissolved gasses in deep hot-water well at Beijing No. 2 Cotton Mill and their relation with seismicity of the region. An
empirical formula for the relation of the precursory anomaly of He and H2 gasses with the magnitude and occurrence time of earthquake has been derived. Two events of magnitude greater than 5 in North
China had been successfully predicted by using this formula.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 490–497, 1993. 相似文献
9.
In this paper, the MYCIN inexact inference method in Expert System is applied to comprehensive earthquake prediction. And
it is proposed that the methods of determining various certainty factors, correcting correlation between anomalous evidences
and computing comprehensive certainty factor of occurrence of some moderate or strong earthquake. By use of these methods,
18 earthquake cases since 1966 in North China is tested with seismological anomalies in different seismogenic stage, and the
comprehensive certainty factors of occurrence of some moderate or strong earthquake are computed. At last some problems in
application are discussed.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 328–337, 1991. 相似文献
10.
Estimation of the Maximum Earthquake Magnitude, <Emphasis Type="Italic">m</Emphasis><Subscript>max</Subscript> 总被引：1，自引：0，他引：1
This paper provides a generic equation for the evaluation of the maximum earthquake magnitude mmax for a given seismogenic zone or entire region. The equation is capable of generating solutions in different forms, depending on the assumptions of the statistical distribution model and/or the available information regarding past seismicity. It includes the cases (i) when earthquake magnitudes are distributed according to the doubly-truncated Gutenberg-Richter relation, (ii) when the empirical magnitude distribution deviates moderately from the Gutenberg-Richter relation, and (iii) when no specific type of magnitude distribution is assumed. Both synthetic, Monte-Carlo simulated seismic event catalogues, and actual data from Southern California, are used to demonstrate the procedures given for the evaluation of mmax.The three estimates of mmax for Southern California, obtained by the three procedures mentioned above, are respectively: 8.32 ± 0.43, 8.31 ± 0.42 and 8.34 ± 0.45. All three estimates are nearly identical, although higher than the value 7.99 obtained by Field et al. (1999). In general, since the third procedure is non-parametric and does not require specification of the functional form of the magnitude distribution, its estimate of the maximum earthquake magnitude mmax is considered more reliable than the other two which are based on the Gutenberg-Richter relation. 相似文献
11.
According to geological tectonics and seismic activites this paper devided North China (30°–45°N, 105°–130°E) into four areas.
We analyzed the North China earthquake catalogue from 1970 to 1986 (from 1965 to 1986 for Huabei, the North China, plain region)
and identified forty-two bursts of aftershock. Seven of them occurred in aftershock regions of strong earthquakes and seventeen
of them in the seismic swarm regions. The relation between strong earthquakes with the remaining eighteen bursts of aftershocks
has been studied and tested statistically in this paper. The result of statistical testing show that the random probabilityp of coincidence of bursts of aftershock with subsequent strong earthquakes is less than six percent. By Xu’sR scoring method the efficacy of predicting strong earthquake from bursts of aftershock is estimated greater than 39 percent.
Following the method proposed in the paper we analyzed the earthquake catalogue of China from 1987 to June, 1988. The results
show that there was only one burst of aftershock occurred on Jan. 6, 1988 withM=3.6 in Xiuyan of Northeast China. It implicates that a potential earthquake withM
S⩽5 might occur in one year afterwards in the region of Northeast China. Actually on Feb. 25, 1988 an earthquake withM
S=5.3 occurred in Zhangwu of Northeast China. Another example is Datong-Yanggao shock on October 18, 1989 which is a burst
of aftershock. Three hours after an expected shock withM =6.1 took place in the same area. Two examples above have been tested in practical prediction and this shows that bursts
of aftershocks are significant in predicting strong earthquakes.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 273–280, 1991.
Part of earthquake catalogue is from Jinbiao Chen, Peiyan Chen and Quanlin Li. 相似文献
12.
13.
14.
Shao-Xie Xu 《地震学报(英文版)》1993,6(2):517-533
The method of prediction of earthquake by using seismisity (MPES) is to make use of the message of earthquakes (including
large, middle, small) in pre-period to predict large earthquake in post-period. Some better methods are presented in this
paper which are selected among many means used in our country recent years. These methods are classified into six sets: 1.
Method of spatial pattern; 2. Method of time process; 3. Method of seismic sequence; 4. Method of earthquake correlation;
5. Method of parameters of seismic source and medium; 6. Comprehensive method. Prediction effects of each method are evaluated
with unique score. The value of each method, scoreR, are generally in a range between 0.3 and 0.6. This value only represents internal consistency, however, the ability of actual
prediction belongs to the extensional effect, which is generally lower than the value of internal consistency. If the ability
of actual prediction could be evaluated withR = 0.3, the ability of prediction of earthquake by seismicity will be stated as following: If most of earthquakes must be
predicted, the warning time needs to take seventy percent of whole time period of prediction; If half earthquakes must be
predicted, the warning time needs to take twenty percent of whole time period of prediction.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 239–252, 1993. 相似文献
15.
16.
Probabilistic seismic hazard analysis (PSHA) has been carried out for Iraq. The earthquake catalogue used in the present study covers an area between latitude 29°–38.5° N and longitude 39°–50° E containing more than a thousand events for the period 1905–2000. The entire Iraq region has been divided into thirteen seismogenic sources based on their seismic characteristics, geological setting and tectonic framework. The completeness of the seismicity catalogue has been checked using the method proposed by Stepp (1972). The analysis of completeness shows that the earthquake catalogue is not complete below Ms=4.8 for all of Iraq and seismic source zones S1, S4, S5, and S8, while it varies for the other seismic zones. A statistical treatment of completeness of the data file was carried out in each of the magnitude classes. The Frequency Magnitude Distributions (FMD) for the study area including all seismic source zones were established and the minimum magnitude of complete reporting (Mc) were then estimated. For the entire Iraq the Mc was estimated to be about Ms=4.0 while S11 shows the lowest Mc to be about Ms=3.5 and the highest Mc of about Ms=4.2 was observed for S4. The earthquake activity parameters (activity rate , b value, maximum regional magnitude mmax) as well as the mean return period (R) with a certain lower magnitude mmin m along with their probability of occurrence have been determined for all thirteen seismic source zones of Iraq. The maximum regional magnitude mmax was estimated as 7.87 ± 0.86 for entire Iraq. The return period for magnitude 6.0 is largest for source zone S3 which is estimated to be 705 years while the smallest value is estimated as 9.9 years for all of Iraq.The large variation of the b parameter and the hazard level from zone to zone reflects crustal heterogeneity and the high seismotectonic complexity. The seismic hazard near the source boundaries is directly and strongly affected by the change in the delineation of these boundaries. The forces, through which the geological structure along the plate boundary in Eastern and Northeastern Iraq are evolved, are still active causing stress-strain accumulation, deformation and in turn producing higher probabilities of earthquake activity. Thus, relatively large destructive earthquakes are expected in this region. The study is intended to serve as a reference for more advanced approaches and to pave the path for the probabilistic assessment of seismic hazard in this region. 相似文献
17.
Jiazheng Qin 《地震学报(英文版)》1992,5(3):563-578
In the light of the single scattering model of coda originating from local earthquakes, and based on the aftershock coda registered
respectively at the 4 short period stations installed near the foci shortly after theM7.6 Lancang andM7.2 Gengma earthquakes, this paper has tentatively calculated the rate of amplitude attenuation and theQ
c-value of the coda in the Lancang and Gengma areas using a newly-founded synthetic determination method. Result of the study
shows the rate of coda amplitude attenuation demonstrates remarkable regional differences respectively in the southern and
northern areas. The southern area presents a faster attenuation (Q
c=114), whereas the northern area shows a slower attenuation (Q
c=231). The paper also discusses the reasons causing such differences. Result of the study also suggests a fairly good linear
relation between the coda source factorA
o(f) and the seismic moment and the magnitude. Using the earthquake scaling law, the following formulas can be derived: lgM
0=lgA
0(f)+17.6,M
D=0.67lgA
0(f)+1.21 and logM
0=1.5M
D+15.79. In addition, the rates of amplitude attenuationβ
s andβ
m are respectively calculated using the single scattering and multiple scattering models, and the ratioβ
s/βm=1.20−1.50 is found for the results respectively from the two models. Finally, the mean free pathL of the S-wave scattering in the southern and northern areas are determined to be 54 km and 122 km respectively by the relations
which can distinguish between the inherentQ
i and scatteringQ
s, testify to this areas having lowQ-values correspond to stronger scatterings.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 71–82, 1992.
This study is partly supported by the Seismological Science Foundation of the State Seismological Bureau of China, and the
present English version of the paper is translated from its Chinese original by Wenyi Xia, Seismological Bureau of Yunnan
Province. 相似文献
18.
Liu Jianming Wang Qiong Nie Xiaohong Gao Ge Zhang Linlin Zhang Zhiguang Xiang Yang 《中国地震研究》2017,31(3):381-394
This paper introduces the basic parameters, focal mechanism solutions and earthquake sequence characteristics of the Kalpin MS5.3 earthquake sequence of December 1, 2013, and analyzed seismic activity before the earthquake, the adjacent tectonic features and the precursory anomaly at fixed points within a range of 200km. Research indicates:(1) The earthquake occurred on Kalpin fault, the source rupture type is thrust faulting with sinistral strike-slip component. (2) The earthquake sequence is mainshock-aftershock type, with the aftershock distribution attenuating quickly and trending NE. (3) Abnormal seismic activity before the earthquake was characterized by seismically nesting quiescence of MS2.0-4.0 earthquakes, seismic quiescence of MS4.0 earthquakes and seismic belts of MS3.0 earthquakes in the Kalpin block, abnormal enhancement zone of moderate earthquakes on Puchang fault and seismological parameters. (4) Anomalies of precursory observation data at fixed stations are mainly characterized by mutation. Apart from the borehole tiltmeter in Halajun, the spatial distribution of other abnormal precursors showed a phenomenon of migration from the near field to far field and from the epicenter to the peripheries. 相似文献
19.
基于新10井水位对九寨沟M_S7.0、精河M_S6.6地震的同震响应特征,分别利用水震波和潮汐分析法,反演得到了新10井水位在地震波作用期间和地震波作用前后含水层参数特征,探讨了2次地震引起的新10井同震响应变化机理。结果表明,新10井水位对九寨沟地震和精河地震具有不同的同震响应形态,利用水平流模型反演所得的新10井含水层渗透系数,在九寨沟地震时为61m/d,而在精河地震时为147m/d,表明地震波作用导致水平向的渗透性增强;利用垂向流模型反演得到的新10井含水层渗透系数,在2次地震之前约为49×10~(-5)m/d,而在地震之后约为18×10~(-5)m/d,表明地震波作用导致垂直向的渗透性减弱。因此,新10井水位的同震响应变化与地震波引起的含水层渗透率的改变有关。 相似文献
20.
回顾了2013年郭增建提出的基于地震活动性的"静中动"和后期与作者共同发展的"准静中动"方法,以1987年1月8日在甘肃南部迭部县发生的5.9级地震作为标志性的"准静中动"地震,结合国家地震局在1989年综合划定的1990—2000年南北地震带10年地震危险区,用中长期预测的时间尺度,指出了南北地震带北段三个未来可能发生6~7级地震的地区,其中一个就是四川省九寨沟地区。回顾分析中对"静中动"方法预测效能、存在的问题及一些中长期预测的问题进行讨论,得到两点认识:一是通过这次地震的再次验证,证明"静中动"方法是一种可行的预测地震的独立指标方法,在验证的基础上对该方法进行了优化认识;二是基于"静中动"方法与南北地震带北段10年地震危险区对应地震较为准确的启发,初步认为前兆可以划分为平静期的前兆与活跃期的前兆,而前者可能对于地震的预测意义更大,未来可以沿这一思路开展进一步的论证和研究。 相似文献