共查询到19条相似文献,搜索用时 156 毫秒
1.
1505年10月9日6(3/4)级地震震中原订在黄海(32.8°N,122.7°E)。1983年以后,因苏南、泰山核电站选址和上海地震烈度复核需要,有人对原定震中提出怀疑,并进行部分修正。我们对1505年地震震中做了考证研究,主要根据地震史料,同时也考虑同期历史地震分布、现代微小地震条带、构造地貌、活动构造和深部构造,建议将1505年6(3/4)级地震震中南移到长江口(30.9°N,122.7°E),并称为1505年长江口6(3/4)级地震。 相似文献
2.
1948年山东威海地震再调查和参数校订 总被引:3,自引:0,他引:3
194 8年 5月 2 3日山东威海附近发生一次强烈地震。李善邦先生将该地震震级定为 6级 ,震中位置定为北纬 37 7°、东经 1 2 1 9° (中央地震工作领导小组办公室 ,1 971 ) ,该位置位于海中。在此以后的各种版本地震目录中 ,都沿用了这一震中位置。自 1 983年以后的各版中国地震目录中 ,又同时给出了微观震中 (顾功叙等 ,1 983;谢毓寿等 ,1 985、1 989;汪素云等 ,1 999)。微观震中为北纬 37 2°、东经 1 2 1 8°,在陆地上 ,位于文登西。宏观和微观震中之间相差 0 5°。同一地震同时给出两个震中位置 ,且相差较大 ,在认识和应用等方面造成了… 相似文献
3.
根据史料记载,各种地震目录均将东汉灵帝光和三年秋(公元180年)表氏地震震中定在甘肃省高台县西(39.4°N,99.5°E),震中烈度Ⅹ度,震级7(1/2).本文通过对历史地震资料的重新考证和表氏新旧县城遗址的实地考察,对公元180年表氏地震的震中位置作了如下修正:震前的表氏县城位于甘肃省肃南县明花区新墩子城,也应是震中所在地,其地理位置为39.6°N、99.3°E,精度2类;震后重建的县城在今骆驼城或草沟井城.通过对史料震害的认真分析,并将本次地震与两汉时期8次6(1/2)级以上地震及高台附近地区9次地震的地震参数、震害和波及范围进行对照,最终将震中烈度修正为Ⅸ—Ⅹ度,震级修正为7级. 相似文献
4.
5.
6.
7.
8.
金宣宗兴定三年(公元1219年),在今宁夏回族自治区南部发生强烈地震,现有文献给出的地震次数、地震时间、震中位置差异很大.本文根据我国地震史料和近年固原发现的碑文和地方志记载,考证该强震时间在六月十八日巳时(公历格列历8月6日10时前后);震中在固原南(35.6°N,106.2°E);震级为61/2级;震中烈度为Ⅷ至Ⅸ度. 相似文献
9.
1955年9月23日,渡口市仁和区与会理县交介的拉、鱼鲊发生了63/4级强烈地震。震中烈度为Ⅸ度,震中位置为东经101°56′,北纬26°251′。这次地震造成593人死亡,1103人受伤,例塌房屋15,000间,震裂10,000余间。这次地震强度大,破坏严重,地震前有没有宏观现象 相似文献
10.
1983年10月18日17时53分,宝兴县境内发生一次4.2级地震,微观震中北纬30°05′,东经102°42′。据考察确定,这次4.2级地震宏观震中位于宝兴县城西北18公里,即宝兴县陇东公社先锋大队一带。震中烈度Ⅴ度强,Ⅴ度区长轴呈NE45°方向展布,长约为9公里,短轴长5公里,Ⅴ度区面积为45平方公里。这次地震有感范围较宽,北至小金 相似文献
11.
12.
The 2018,Songyuan,Jilin M_S5. 7 earthquake occurred at the intersection of the FuyuZhaodong fault and the Second Songhua River fault. The moment magnitude of this earthquake is M_W5. 3,the centroid depth by the waveform fitting is 12 km,and it is a strike-slip type event. In this paper,with the seismic phase data provided by the China Earthquake Network, the double-difference location method is used to relocate the earthquake sequence,finally the relocation results of 60 earthquakes are obtained. The results show that the aftershock zone is about 4. 3km long and 3. 1km wide,which is distributed in the NE direction. The depth distribution of the seismic sequence is 9km-10 km. 1-2 days after the main shock,the aftershocks were scattered throughout the aftershock zone,and the largest aftershock occurred in the northeastern part of the aftershock zone. After 3-8 days,the aftershocks mainly occurred in the southwestern part of the aftershock zone. The profile distribution of the earthquake sequence shows that the fault plane dips to the southeast with the dip angle of about 75°. Combined with the regional tectonic setting,focal mechanism solution and intensity distribution,we conclude that the concealed fault of the Fuyu-Zhaodong fault is the seismogenic fault of the Songyuan M_S5. 7 earthquake. This paper also relocates the earthquake sequence of the previous magnitude 5. 0 earthquake in 2017. Combined with the results of the focal mechanism solution,we believe that the two earthquakes have the same seismogenic structure,and the earthquake sequence generally develops to the southwest. The historical seismic activity since 2009 shows that after the magnitude 5. 0 earthquake in 2017,the frequency and intensity of earthquakes in the earthquake zone are obviously enhanced,and attention should be paid to the development of seismic activity in the southwest direction of the earthquake zone. 相似文献
13.
ResearchoncharacteristicsofmagnitudestructureofearthquakesequencesPEI-QINGSUN(孙佩卿)QIN-ZULI(李钦祖)YING-HUADAI(戴英华)JUNZHAO(赵军)Se... 相似文献
14.
内蒙古中西部地区中小地震矩震级研究 总被引:1,自引:1,他引:0
基于S震相"S窗"内的波形信号识别、品质因子Q(f)和22个台站场地响应,利用2009~2016年3月内蒙古中西部地区地震的波形资料,反演了182次中小地震的震源波谱参数,得到这些小震的零频幅值及其拐角频率,据此计算了这些地震的地震矩M_0、矩震级M_W和应力降Δσ。利用回归分析方法得到了近震震级与矩震级、矩震级与应力降的关系式。分析表明,近震震级与矩震级、矩震级与应力降呈线性关系。可见,将矩震级纳入地震的快报与正式目录中,可以丰富地震观测报告内容,更好地为地震应急和地震科研服务。 相似文献
15.
E. M. Scordilis 《Journal of Seismology》2006,10(2):225-236
The existence of several magnitude scales used by seismological centers all over the world and the compilation of earthquake catalogs by many authors have rendered globally valid relations connecting magnitude scales a necessity. This would allow the creation of a homogeneous global earthquake catalog, a useful tool for earthquake research. Of special interest is the definition of global relations converting different magnitude scales to the most reliable and useful scale of magnitude, the moment magnitude, M
W. In order to accomplish this, a very large sample of data from international seismological sources (ISC, NEIC, HRVD, etc.) has been collected and processed. The magnitude scales tested against M
W are the surface wave magnitude, M
S, the body wave magnitude, m
b, and the local magnitude, M
L. The moment magnitudes adopted have been taken from the CMT solutions of HRVD and USGS. The data set used in this study contains 20,407 earthquakes, which occurred all over the world during the time period 1.1.1976–31.5.2003, for which moment magnitudes are available. It is shown that well-defined relations hold between M
W and m
b and M
S and that these relations can be reliably used for compiling homogeneous, with respect to magnitude, earthquake catalogs. 相似文献
16.
2017年8月8日青藏高原东缘四川九寨沟地区发生7.0级强震,依据前人研究结果分析九寨沟7.0级地震发震构造,并计算震前应力状态。结果显示:本次地震受到构造和历史强震的影响,是发生在历史强震引起的应力加载区域。另外,采用中国地震台网1990年以来的地震目录,在评估目录完整性的基础上,利用最大似然法计算得到2017年8月8日九寨沟7.0级地震前震源区及邻区地震b值空间图像。结果显示,九寨沟7.0级地震发生在四川北部地区显著低b值高应力异常区域内部(0.82b0.75)。所以,研究区域内外历史强震可能促进了九寨沟7.0级地震的发生。 相似文献
17.
本文选取2013年芦山地震和2017年九寨沟地震波形,重新量取垂直向振幅,计算宽频带面波震级MS(BB),分析各台站实测震级出现方向性差异的原因。其中,通过572个宽频带台站实测芦山地震震级MS(BB)7.1,通过603个宽频带台站实测九寨沟地震震级MS(BB)6.9。芦山地震实测震级大于MS(BB)7.3的台站呈现WN-ES向分布,与断层倾向一致;实测震级小于MS(BB)7.0的台站呈现NE-WS向分布,与其所在断层走向一致。九寨沟地震实测震级大于MS(BB)7.0的台站分布呈现NE向分布,与断层倾向一致;实测震级小于MS(BB)6.8的台站总体分布较为离散,大体呈现NW-SE向分布,与树正断裂走向一致。实测震级偏大的台站方向性分布与多普勒效应和P波辐射花样联系不明显。对比分析芦山地震和九寨沟地震,去除场地响应和仪器自身影响,台站实测震级差异性仍然存在,因此,台站实测震级差异性是由于受到了多普勒效应、辐射花样、仪器和场地响应之外的因素影响。综合考虑地震震级涉及的影响因素,芦山地震和九寨沟地震的台站实测震级差异性可能与地震波的传播路径有关。 相似文献
18.
青藏高原东北隅地区位于青藏高原、鄂尔多斯和阿拉善三大块体交汇部位,发育一组以逆走滑活动为主的弧形断裂系,其新活动性强,历史及现代强震频发,是探讨现代中小地震密集区与历史强震关联性的理想地区,也是检验和发展小震密集区值方法及其适用条件的有利地区。本文采用甘肃省地震局对该区1970年以来1~5级地震仪器监测目录,利用网格点密集值方法进行计算分析,共划分出21个地震密集区。通过分析每个地震密集区内小震活动的时间分布特征及前人对历史地震和活动构造的研究结果,综合判断地震密集区与历史强震之间的对应关系,归纳总结不同震级历史强震密集区的持续时间,给出运用网格点密集值方法校核青藏高原东北隅历史地震的限定条件。研究结果表明:青藏高原东北隅弧形构造区大约66.7%的密集区对应历史强震,两者之间有较密切的关联性;且地震震级越大密集区持续时间越长,两者之间的拟合关系为:T=4.38×10~(-7)×M~(10.91)。 相似文献
19.
Viacheslav K. Gusiakov 《Pure and Applied Geophysics》2011,168(11):2033-2041
Operational prediction of near-field tsunamis in all existing Tsunami Warning Systems (TWSs) is based on fast determination
of the position and size of submarine earthquakes. Exceedance of earthquake magnitude above some established threshold value,
which can vary over different tsunamigenic zones, results in issuing a warning signal. Usually, a warning message has several
(from 2 to 5) grades reflecting the degree of tsunami danger and sometimes contains expected wave heights at the coast. Current
operational methodology is based on two main assumptions: (1) submarine earthquakes above some threshold magnitude can generate
dangerous tsunamis and (2) the height of a resultant tsunami is, in general, proportional to the earthquake magnitude. While
both assumptions are physically reasonable and generally correct, statistics of issued warnings are far from being satisfactory.
For the last 55 years, up to 75% of warnings for regional tsunamis have turned out to be false, while each TWS has had at
least a few cases of missing dangerous tsunamis. This paper presents the results of investigating the actual dependence of
tsunami intensity on earthquake magnitude as it can be retrieved from historical observations and discusses the degree of
correspondence of the above assumptions to real observations. Tsunami intensity, based on the Soloviev-Imamura scale is used
as a measure of tsunami “size”. Its correlation with the M
s and M
w magnitudes is investigated based on historical data available for the instrumental period of observations (from 1900 to present). 相似文献