区域地震台网M_L震级系统的连续过渡问题
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摘要
根据福建区域数字地震台网建立之后 ,数字和模拟二类地震仪在同一台站同时观测到的几十个地震的基本参数测定结果 ,讨论了当前区域地震台网从模拟仪器观测向全数字化仪器观测过渡过程中 ,如何生成连续的 ML 震级系统问题。着重讨论了数字地震信号“仿真”处理技术在区域数字台网地震基本参数测定中的应用问题 ,尤其是利用宽频带速度平坦型数字地震记录进行 ML 震级测定 ,生成与原来模拟台网测定的 ML 震级的“无缝”衔接问题。统计结果表明 ,利用近似仿真方法将 JCV- 1 0 0短周期速度型数字记录转换成 DD- 1短周期位移型模拟记录 ,则二个系统的 ML 震级测定的统计偏差可以小于± 0 .1个震级单位。如果进一步进行严格仿真 ,可以进一步减少这个偏差范围 ,从而生成该区域台网连续的 ML 震级系统
In this paper, the authors discussed the problem of how to create a continuous M L magnitude system in regional seismic network during the transitional process from analogous observation system to full digital observation system. They used the determined seismic parameters obtained from tens of seismic records of Fujian and Taiwan region from Fujian regional digital seismic network, and records from the same station by both digital and analogous seismographs synchronously. It was emphasized that the application of the emulation technique of digital seismic signal in determining seismic basic parameters, especially in determining M L magnitude by using broad band velocity type digital seismograph so as to generate a “seamless” regional seismic catalog. The statistical results show that using approximate emulate method to convert the waveform of JCV 100 short period velocity type digital records into that of DD 1 short period displacement type analog records, the statistical error of M L magnitudes between the two system could be less than ±0.1 magnitude unit. If the strict emulation would be further made, including correction of instrument response and emulation of waveform and amplitude, then the error range could be reduced further so that a continuous M L magnitude system could be created in the regional seismic network.
In this paper, the authors discussed the problem of how to create a continuous M L magnitude system in regional seismic network during the transitional process from analogous observation system to full digital observation system. They used the determined seismic parameters obtained from tens of seismic records of Fujian and Taiwan region from Fujian regional digital seismic network, and records from the same station by both digital and analogous seismographs synchronously. It was emphasized that the application of the emulation technique of digital seismic signal in determining seismic basic parameters, especially in determining M L magnitude by using broad band velocity type digital seismograph so as to generate a “seamless” regional seismic catalog. The statistical results show that using approximate emulate method to convert the waveform of JCV 100 short period velocity type digital records into that of DD 1 short period displacement type analog records, the statistical error of M L magnitudes between the two system could be less than ±0.1 magnitude unit. If the strict emulation would be further made, including correction of instrument response and emulation of waveform and amplitude, then the error range could be reduced further so that a continuous M L magnitude system could be created in the regional seismic network.
引文
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[2 ] 王广福 .我国基准台上用的十二种地震仪的传递函数、频率特性和时间特性 [J].地震地磁观测与研究 ,1 983,4(3) :1 - 2 9.
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[4] Robert A Uhrhammer,Suzanna J Loper,Barbara Romanowicz. Calculation of Local MagnitudeAdopting the broad- band records in the Berkeley digitalseismicnetwork[J].BSSA,1 996,86(5) :1 2 1 4- 1 2 2 0 .
[5] 刘瑞丰 ,党金平 ,陈培善 .利用速度型数字地震仪器记录测定面波震级 [J].地震地磁观测与研究 ,1 996,1 7(2 ) :1 7- 2 1 .
[2 ] 王广福 .我国基准台上用的十二种地震仪的传递函数、频率特性和时间特性 [J].地震地磁观测与研究 ,1 983,4(3) :1 - 2 9.
[3] 陈祥熊 ,江燕 .数字地震仪原理及其频率响应函数和传递函数——地震学上用的数字信号处理的基本原理与实例 (讲座 2 ) [J].地震地磁观测与研究 ,1 998,1 9(1 ) :2 6- 34.
[4] Robert A Uhrhammer,Suzanna J Loper,Barbara Romanowicz. Calculation of Local MagnitudeAdopting the broad- band records in the Berkeley digitalseismicnetwork[J].BSSA,1 996,86(5) :1 2 1 4- 1 2 2 0 .
[5] 刘瑞丰 ,党金平 ,陈培善 .利用速度型数字地震仪器记录测定面波震级 [J].地震地磁观测与研究 ,1 996,1 7(2 ) :1 7- 2 1 .
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