【作者】 任克新；

【导师】 刘瑞丰；

【作者基本信息】 中国地震局地球物理研究所 ， 地球探测与信息技术， 2009， 硕士

【摘要】 震级是表征地震强弱的量度,是地震的基本参数之一。不同的地震机构测定震级存在一定差异。基于数字地震仪器的震级测定问题引起了国际地震学与地球内部物理学联合会（IASPEI）和各个国家的高度重视。IASPEI于2001年成立了专门的震级工作组开展宽频带数字地震资料震级测定的研究工作。经过几年的努力,IASPEI震级工作组做了大量的基础性研究,积累了大量的实际观测资料,于2003年提出了新的震级标度和测量方法,2005年10月在智利圣地亚哥召开的IASPEI会议上,IASPEI地震观测与资料解释委员会（CoSOI）通过了震级工作组提出的新的震级标度及其测量方法。IASPEI新的体波震级有短周期体波震级m_b和宽频带体波震级m_B（BB）,面波震级有20s面波震级M_S（20）和宽频带面波震级M_S（BB）。IASPEI新震级标度的建立主要基于两个基本的考虑,一是要考虑震级测定的连续性,二是要充分利用宽频带数字地震记录的特点。为了推广IASPEI新震级标度,并保证震级的连续性和兼容性,必须分析研究IASPEI新震级标度和传统震级标度之间的关系。中国地震台网在“九五”期间建立了数字地震台站,积累了丰富的宽频带数字地震波形资料,为研究IASPEI新震级标度和中国传统震级标度之间的关系提供了坚实的基础。通过本项研究,推荐出能够在全球范围推广使用的震级计算规范,同时为我国制定数字地震台站（网）观测技术规范提供重要基础资料,使新的震级标度能够在我国地震台网日常产出中应用,促进我国的震级测定与国际接轨。采用IASPEI新推荐的体波震级和面波震级标度,选取2001年至2007年国家数字地震台网的48个数字地震台站且震中距小于100°具有代表性的564个地震事件为研究对象,利用SHM软件测定新标度下短周期体波震级m_b（i）、宽频带体波震级m_B（i）、宽频带面波震级M_S（BB）、20s面波震级M_S（20）,应用同样的资料同时测定中国传统震级标度下的短周期体波震级m_b、中长周期体波震级m_B、763面波震级M_S7和长周期面波震级M_S。使用一般线性回归分析和正交回归分析方法将中国传统震级标度不同震级之间、IASPEI新震级标度不同震级之间、传统震级与IASPEI新震级标度同种类震级之间进行回归分析,给出了不同震级之间的回归关系式,并对这些回归结果进行了详细的解释说明。IASPEI新震级标度的制定可以促进世界各国地震机构震级值的统一,新标度短周期体波震级m_b（i）能够更加准确地反映较大地震的辐射能量,宽频带体波震级m_B（i）和面波震级M_S（BB）能够更加快速地确定地震的震级,而M_S（20）和中国传统震级M_S7之间不存在系统的误差,因此中国地震台网可以先行采用IASPEI新震级标度进行震级计算,使我国地震台网的资料产出逐步与国际接轨。本论文第一章对地震震级的发展以及国内外现状进行了概述,同时引出了本论文的研究背景和研究目的。在第二章详细介绍了IASPEI新震级标度和中国传统震级标度的计算公式和量取方法,并分析总结了二者之间存在的差异。第三章介绍了中国数字地震台网的现状以及本论文所用数据的选取工作和波形分析软件。第四章对中国传统震级标度和IASPEI新震级标度计算的震级结果利用一般线性回归方法和正交回归方法进行了对比分析,并给出了回归分析的关系式,详细分析了不同震级之间的关系。在第五章对本文所做的工作给予总结和讨论并提出了需要进一步探讨的问题。更多还原

【Abstract】 Magnitude is one of the basic parameters to measure the size of an earthquake.Different seismological institutions in the world have different magnitude measurements.The issue of the magnitude measurements based on digital seismic instruments has aroused great attention of the IASPEI and many countries.The International Association of Seismology and Physics of Earth’s Interior（IASPEI） founded the Working Group on Magnitude in 2001 to study magnitude measurement with broad-band digital seismic data.With several years’ efforts,the WG has done a lot of basic research and accumulated a large amount of practical observational data.A new magnitude scale and measurement was proposed by the WG in 2003 and this magnitude scale and measurement was approved formally by the IASPEI Commission on Seismological Observation and Interpretation（CoSOI） on the IASPEI 33rd General Assembly held in Santiago,Chile in October 2005.The new IASPEI body wave magnitude scales are short-period body wave magnitude m_b and broadband body wave magnitude m_B（BB）,and the surface wave magnitude scales are 20 s surface wave magnitude m_S（20） and broadband surface wave magnitude m_S（BB）.The proposal of the new magnitude scales is mainly based on two fundamental considerations:one is the continuity of the magnitude measurements,and the other is the full use of the characteristics of the broadband digital seismic records.In order to promote the new IASPEI magnitude scales and ensure the continuity and compatibility of the use of the magnitudes,the relationship between the new IASPEI magnitudes and the traditional scales should be studied.The fact that the China Seismograph Network（CSN） constructed digital seismic stations during the "the 9th Five-Year Plan" and accumulated rich waveform data has laid a solid foundation of studying the relationship between the new IASPEI magnitude scales and the CSN traditional scales.We will not only recommend a worldwide standard of magnitude determination in this study but also provide important fundamental data for making the observatory technical specifications for digital seismic stations/networks in China;so that the new magnitude scales can be applied to the CSN routine work and the magnitude measurements can be in line with international practices.Applying the new recommended body and surface wave magnitude scales,selecting the data from the 564 representative earthquakes between 2001 and 1007,whose distances are less than 100°,recorded by the 48 stations of the China National Digital Seismograph Network,determined the short-period body wave magnitude m_b（i）,broad-band body wave magnitude m_B（i）,broad-band surface wave magnitude M_S（BB）,and 20 s surface wave magnitude M_S（20） on the new scales with the SHM.Meanwhile,we have also determined the short-period body wave magnitude m_b,the middle-/long-period body wave magnitude m_B,the 763 seismometer surface wave magnitude M_S7,and long-period surface wave magnitude M_S on the Chinese traditional scales with the same data.The regression analysis of the magnitudes among the different Chinese traditional scales, among the different new IASPEI scales and between the traditional and IASPEI scales of the same types are respectively made with linear regression and orthogonal regression.Moreover,the regression relationships of the different magnitudes are given and the results of the regression analysis are explained in detail.The new IASPEI magnitude scales will promote the uniformity of the magnitude measurements among the seismological institutions all over the world.The radiant energy of the moderate and large earthquakes can be reflected by the new short-period body wave magnitude m_b（i） more accurately;the magnitude of the earthquake can be determined more quickly with the new broad-band body and surface wave magnitudes m_B（i） and M_S（BB）;There isn’t system error between M_S（20） on the new scale and Chinese traditional M_ST.Therefore,CSN may adopt the new IASPEI magnitude scales in advance,so that the CSN data can gradually keep up with the word development.The first chapter of this dissertation gives an overview of the development and current status of the magnitude research in China and abroad,and from this,leads to the study background and purpose of the dissertation.The formulae and measurements of the new IASPEI magnitude scales and the traditional ones in China are introduced and the differences between the two are summarized in Chapter 2.Chapter 3 makes an introduction to the CSN’s development and the used data and waveform analysis software in this dissertation.Using the general linear regression and the orthogonal regression,the computing results of the magnitudes in Chinese traditional and new IASPEI scales were compared in Chapter 4.Moreover,the regression analysis relational expressions are given and the relationship of the different magnitudes is analyzed in detail in this chapter.The last chapter makes a summary and conclusion of the dissertation and points out some issues for further discussion.更多还原