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1.
Using 116 earthquakes over M_L3.8 in the Inner Mongolia region from 2008 to 2015, the local earthquake magnitude M_L and surface wave magnitude M_S are remeasured. Based on norm linear regression(SR1 and SR2) and norm(OR) orthogonal regression method, we established the conversion relationship between M_L and M_S. The results were tested with Gaussian disturbance. The result shows that the orthogonal regression method(OR) result has the best fitting curve, and the conversion relation is M_S=0.96 M_L-0.10. The difference between our result and Guo Lücan's(M_S=1.13 M_L-1.08) may be caused by regional tectonic characteristics. M_(S Inner Mongolia) value is significantly higher than the M_(S empirical) value, with an average difference of 0.23, the difference distribution of empirical relation and the rectified relation is in the range of 0.2-0.3.  相似文献   

2.
利用青海地震台网记录到的2010年至2017年可同时测定M_L和M_s震级的地震,采用线性回归和正交回归方法对重新仿真后量取的近震震级和面波震级之间的关系进行拟合,并全面分析得到2种震级之间的转换关系式,即M_s=1. 13M_L-0. 80,并与郭履灿转换公式进行对比,两者存在相似性,但因地区差异存在系统偏差,差值大多在0. 3左右。  相似文献   

3.
利用线性回归方法对2010~2018年M_S≥3.5的500个地震事件为研究对象,重新量取计算近震震级M_L和面波震级M_S,并对新疆地区分区域进行对比分析,得出不同区域近震震级与面波震级之间的关系,为定量研究地震震级奠定基础。同时,将新疆台网和中国地震台网都存在的震级数据进行对比,结果表明:新疆台网和中国地震台网测定的M_L震级差值主要分布在-0.2~0.1,M_S震级差值主要分布在-0.4~0.2。  相似文献   

4.
新震级国家标准在四川台网的应用——宽频带面波震级   总被引:1,自引:0,他引:1  
利用四川区域地震台网记录到的国内2009—2016年间的217次地震事件,重新测定宽频带面波震级M_(S(BB))、面波震级M_S和部分矩震级M_W,并进行对比分析,结果显示:(1)M_S与M_(S(BB))差值分布为-0.1~0.6,其中97%的地震M_S较M_(S(BB))偏大,通过正交回归分析,M_(S(BB))较M_S系统偏小0.27左右;(2)M_W与M_S差值为-0.8~0.35,其中M_W与M_S差值在±0.3以内的地震数约为74%,由正交回归分析4.0≤M≤8.0时M_S整体偏大,且偏差值随着震级的增加呈上升趋势,偏大范围为0.1~0.4之间;(3)M_W与M_(S(BB))差值分布为-0.5~0.55,差值在±0.3以内地震占87%,正交回归分析出4.0≤M≤5.0时M_W较M_(S(BB))偏大,偏大范围为0~0.13,而5.0≤M≤8.0时M_W较M_(S(BB))偏小,偏差值均在0.23以内。总体来说,相较于M_S,M_(S(BB))与M_W的偏差更小,M_(S(BB))更接近地震矩震级M_W,更能准确评估地震震级。  相似文献   

5.
利用云南地震台网记录的云南及其周边地区2000~2017年的宽频带数字地震资料,按照新的震级国家标准《地震震级的规定》(GB17740-2017)的测定方法,使用同一套软件,对地方性震级M_L、面波震级M_S、宽频带面波震级M_S(BB)、短周期体波震级m_b、宽频带体波震级m_B(BB)和矩震级M_W重新进行人工测量。并分别用一般线性回归和正交回归方法,对不同震级之间的关系进行对比,给出它们之间的经验关系式。研究结果表明:(1)当M4.5时,各种震级之间相差不大,使用地方性震级M_L可以较好地表示地震的大小,也能够更加充分地反映区域特性;当4.5≤M8.0时,宽频带面波震级M_S(BB)和矩震级MW均能较好地表示地震的大小,但矩震级M_W的测定需要一定时间,因此在速报工作和大震应急中,可以使用M_S(BB)表示地震的大小; M_S(BB)的测定方法与国际接轨,消除0.2的震级偏差。(2)对于面波震级MS和宽频带面波震级M_S(BB),由于面波测量的位置、计算公式和量归函数不同,M_S比M_S(BB)系统偏高0.2左右;短周期体波震级mb较宽频带体波震级m_B(BB)整体偏小0.2左右,主要区别在于仿真模式。(3)宽频带面波震级M_S(BB)和宽频带体波震级m_B(BB)均在垂直向原始宽频带记录上直接测定,取消波形仿真环节,另外,相比测定m_B(BB)震中距要求大于5度,许多台站被限制,M_S(BB)更利于区域台网测定。(4)当3.5≤ML≤6.5时,M_L较M_W整体偏大; M_S≥3.5时,M_S也较M_W整体偏大,且均随着震级增加,偏差值呈上升趋势。(5)当M≥8.0时,面波震级出现饱和现象,使用矩震级M_W表示M≥8.0地震的大小。  相似文献   

6.
震源断裂规模与震级的定量关系   总被引:2,自引:1,他引:2       下载免费PDF全文
研究震源参数(震源断裂规模)与震级的定量关系必须考虑震级的物理含义。本文利用我国海城地震、唐山地震前后的151个小震(1.5≤M_L≤3.9)和国内外58个浅源的中、强震(4.4≤M_s≤8.2)资料,得到了一组稳定的、互相一致的震源断裂参数与震级M_L和M_S的函数关系。由此讨论了常用震级M_L、M_S与m_b之间的关系。 新的震源参数与震级关系表明,震源断裂规模如断裂长度、面积或错距等与面波震级M_S和近震震级M_L不存在一一对应的比例关系  相似文献   

7.
地震预警技术是减轻地震灾害的有效手段之一,而在预警系统中,震级的测定是最重要,也是最困难的。考虑到地震预警震级估算方法的区域性特点,本文利用内蒙古测震台网2016~2018年M_L≥2. 0地震波形数据共120条,分别采用P波3s时间窗内垂直向位移时程和P波全波段垂直向位移时程计算特征周期参数值,得到了地震预警震级的计算公式,并对其结果进行对比分析。结果显示,采用P波全波段关系式得到的结果较采用P波3s固定时间窗计算值收敛性更好,关系式拟合相关系数更接近1,能够对预警地震震级做出较好的估计。同时结合数据处理结果,探讨了地震预警的警报快速性和准确性之间的关系。  相似文献   

8.
云南地区近震震级与面波震级转换关系研究   总被引:2,自引:1,他引:1  
利用云南地区数字地震台站记录的云南及周边地区2000~2011年4.0级以上可同时测定近震震级ML和面波震级MS的433个地震波形数据,将速度数据进行仿真,即近震震级ML在仿真短周期地震仪DD-1记录上测定,面波震级MS在仿真中长周期地震仪SK记录上测定,对全部人工重新测定的ML和MS,采用线性回归和正交回归方法,得到了它们之间的转换关系式。结果表明,自20世纪70年代使用至今的公式MS = 1.13ML - 1.08与云南地区实际情况存在系统偏差,已不适用于云南地区。考虑到区域差异,认为采用关系式MS = 1.13ML - 0.86作为新的转换关系更合理适用。同时,对云南地震台网和国家地震台网都有记录的地震数据进行对比,发现云南台网和国家台网测定的绝大多数地震ML差值为- 0.2~ 0.4,差值为0.2的地震数量最多;MS差值为-0.4~0.2,差值为-0.2的地震数量最多。  相似文献   

9.
利用模板匹配方法对2015年11月23日青海省祁连县M_S5.2地震进行遗漏地震检测研究,由于主震后短时间内目录中遗漏事件较多,故对主震后1天的连续波形进行检测。主震后1天内青海测震台网记录到的余震个数(包括单台)共62个,选取主震后M_L1.0以上余震30个作为模板事件,通过匹配滤波的方式扫描出遗漏地震31个,约为台网目录给出的0.5倍。基于包络差峰值振幅与震级的线性关系估测检测事件的震级参数,最后将检测后的余震目录与台网余震目录在主震后1天内的最小完备震级进行对比分析,结果发现检测后最小完备震级从M_L1.2降到了M_L0.7,得到青海测震台网在祁连地区最小完整性震级为M_L0.7。  相似文献   

10.
基于震级残差统计、线性回归和正交回归方法,选取2008年至2016年3月内蒙古测震台网记录的内蒙古东部地区地震观测报告和波形事件,确立该区量规函数,建立近震震级与面波震级间的转换关系。研究表明,HLH、HLR和AGL等5个台站震级偏差较大,可能由地震台站场地响应衰减或放大、台基风化等造成;全国量规函数仅在140 kmΔ≤280 km时适用于内蒙古东部地区;采用正交回归方法(OR)得到古东部地区M_(S东部)=0.99M_L-0.12。  相似文献   

11.
In this paper, we give a brief introduction to the proposal and development history of the earthquake magnitude concept. Moment magnitude MW is the best physical quantity for measuring earthquakes. Compared with other magnitude scales used traditionally, moment magnitude is not saturated for all earthquakes, regardless of big and small earthquakes, deep and shallow earthquakes, far field and near field seismic data, geodetic and geological data, moment magnitude can be measured, and can be connected with well-known magnitude scales such as surface wave magnitude MS. Moment magnitude is a uniform magnitude scale, which is suitable for statistics with wide magnitude range. Moment magnitude is the preferred magnitude selected by the International Seismological community, and it is preferred by the departments responsible for publishing seismic information to the public.Moment magnitude is a uniform magnitude scale, which is suitable for statistics with wide magnitude range. Moment magnitude is a preferred magnitude for international seismology, it is preferred by the agency responsible for providing information about earthquakes to the public. We provide all formulas used in the calculation of moment magnitude, and the calculation steps in detail. We also analyzed some problems and rules to solve these problems by using different formulas and numerical value calculation steps.  相似文献   

12.
The New Magnitude National Standard of General Rules for Earthquake Magnitude( GB17740-2017) is the state mandatory standard. It was released on May 12,2017,by the General Administration of Quality Supervision,Inspection and Quarantine of the Peoples Republic of China and the Standardization Administration of the Peoples Republic of China. This paper introduces the necessity of revising the national standard of magnitude,and the main contents,technical points and primary features of the new national standard of magnitude,so that it can be applied better in practice.  相似文献   

13.
孙冬军  刘芳  毕波 《中国地震》2022,38(1):112-119
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   

14.
The maximum likelihood estimation of theb parameter in the Gutenberg-Richter relation is extended to the case of uncertain magnitude. An interval which contains the real unknown magnitude is used rather than the uncertain magnitude itself. The proposed approach is very flexible, it allows for the combination of the parts of a catalog of different quality into a single minimally biased set of recurrence parameters.On leave from the Institute of Geophysics, Polish Academy of Sciences, 00-973 Warsaw, Pasteura 3, Poland  相似文献   

15.
Large data sets covering large areas and time spans and composed of many different independent sources raise the question of the obtained degree of harmonization. The present study is an analysis of the harmonization with respect to the moment magnitude M w within the earthquake catalogue for central, northern, and northwestern Europe (CENEC). The CENEC earthquake catalogue (Grünthal et al., J Seismol, 2009) contains parameters for over 8,000 events in the time period 1000–2004 with magnitude M w ≥ 3.5. Only about 2% of the data used for CENEC have original M w magnitudes derived directly from digital data. Some of the local catalogues and data files providing data give M w, but calculated by the respective agency from other magnitude measures or intensity. About 60% of the local data give strength measures other than M w, and these have to be transformed by us using available formulae or new regressions based on original M w data. Although all events are thus unified to M w magnitude, inhomogeneity in the M w obtained from over 40 local catalogues and data files and 50 special studies is inevitable. Two different approaches have been followed to investigate the compatibility of the different M w sets throughout CENEC. The first harmonization check is performed using M w from moment tensor solutions from SMTS and Pondrelli et al. (Phys Earth Planet Inter 130:71–101, 2002; Phys Earth Planet Inter 164:90–112, 2007). The method to derive the SMTS is described, e.g., by Braunmiller et al. (Tectonophysics 356:5–22, 2002) and Bernardi et al. (Geophys J Int 157:703–716, 2004), and the data are available in greater extent since 1997. One check is made against the M w given in national catalogues and another against the M w derived by applying different empirical relations developed for CENEC. The second harmonization check concerns the vast majority of data in CENEC related to earthquakes prior to 1997 or where no moment tensor based M w exists. In this case, an empirical relation for the M w dependence on epicentral intensity (I 0) and focal depth (h) was derived for 41 master events, i.e., earthquakes, located all over central Europe, with high-quality data. To include also the data lacking h, the corresponding depth-independent relation for these 41 events was also derived. These equations are compared with the different sets of data from which CENEC has been composed, and the goodness of fit is demonstrated for each set. The vast majority of the events are very well or reasonably consistent with the respective relation so that the data can be said to be harmonized with respect to M w, but there are exceptions, which are discussed in detail.  相似文献   

16.
以青海、新疆、西藏地区为研究区域,系统研究总结了该区域2010—2020年5.0级以上地震前Wq值的时空演化特征,并以2020年新疆于田6.4级和西藏尼玛6.6级地震为实例进行阐述。得出以下三点认识:①地震一般发生在Wq值异常扩展时段或扩展—减小时段,6.0级以上Wq值异常的震例中,约81%发生于异常出现后的9个月内;②地震一般位于Wq值异常面积扩展区或扩展—减小恢复区附近,近70%的震例发生在Wq值异常区内;③建立了震级与Wq值异常区面积间的正相关统计模型,二者的相关系数(R)为0.85,为预测青海、新疆和西藏地区地震的强度提供了定量关系。青海、新疆和西藏地区Wq值方法对6.0~6.9级地震的预测效果(Wq值异常的地震报准率为61%)优于5.0~5.9级地震(Wq值异常的地震报准率为26%),为我国地球物理观测程度较低地区开展强震中短期(1年内)预测提供了参考依据。  相似文献   

17.
甘肃近期几次中强地震震源机制解   总被引:2,自引:1,他引:2       下载免费PDF全文
12002年12月14日玉门MS5.9地震发震时间:21∶27′27″;经纬度:39.8°N,97.3°E;深度:33km;震级:MS5.9。收集了全省及邻近省份共同31个台站初动后作出震源机制解(表1,图1)。表1 玉门MS5.9地震震源参数节面A节面BP轴T轴N轴矛盾比/%走向倾角滑动角走向倾角滑动角方位角仰角方位角仰角方位角仰角147°26°35°24°75°111°277°27°140°55°18°21°0.09722003年10月25日民乐-山丹MS6.1地震发震时间:20∶41′36.4″;经纬度:38.33°N,100.95°E;深度:12km;震级:MS6.1。收集了全省21个台站初动后作出震源机制解(表2,图2)。表2 民乐-山…  相似文献   

18.
韩光洁  孙丽  杨志高 《中国地震》2023,39(3):680-688
利用远场台阵反投影技术可以较少地依赖先验经验,于震后快速获得震源破裂过程时空分布特征,并据此估算矩震级。本文使用美国阿拉斯加宽频带台阵记录到的远场直达P波数据,基于反投影方法,对2023年9月9日摩洛哥MW6.9地震震源破裂过程及震级进行分析。结果显示,地震破裂走向以NE-SW向为主,地震能量在10~20s集中在震中距10km范围内释放,与震源机制解和震中区亚特拉斯山脉走向基本一致。震源破裂持续时间结合在全球分布均匀的GSN台网记录到的P波最大位移数据,在震后约15min即可快速估算出本次地震矩震级为MW7.0,与中国地震台网中心和美国地质调查局发布震级基本一致。  相似文献   

19.
A method for the determination of consistent local magnitude M L values (Richter scale, or M WA) for earthquakes with epicentral distances ranging from 10 km through 1000 km is demonstrated. The raw data consists of nearly 1300 amplitude readings from a network of six digital seismographs in Baden–Württemberg (Southwestern Germany) during 26 months starting in 1995, later extended by another 1000 amplitude readings until 1999. Relying on most of the basics introduced by C.F. Richter a three-parameter attenuation curve (distance correction, magnitude-distance relation) for Baden–Württemberg and adjacent areas is presented. Station corrections are evaluated and the attenuation curve is calibrated with respect to other agencies for distances greater than 650 km. Reasonable parametrisations are discussed and meaningful error bars are attributed. Finally, a seventh station is incorporated by means of its station correction alone, without needing to update the attenuation curve.  相似文献   

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