环境剪应力值τ_0的稳定性和预测效能分析
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摘要
利用峰值加速度ap、峰值速度vp和峰值位移dp,计算了广东省河源地区64个地震的环境剪应力值0τ。结果表明,同一地震的0τa、τ0v、0τd可相差很大,0τv、0τd的误差主要来自地震矩M0。因此,如果不能从震源谱计算M0,则以峰值加速度方法计算0τ误差最小。剪应力值为使用震级序列分析地震趋势提供了明确的物理基础。即高震级地震多发说明应力场处于高强度背景,有发生更大地震的可能;反之则为低应力场背景,发生更大地震的可能性不大。公式分析和实际数据拟合得到lg(0τ)与ML有很好的线性相关,因此震级序列与剪应力值序列的地震预测效能是基本相同的。但与震级序列相比,0τ的计算显然要复杂,且误差也较大。
The environment shear stress τ_0 for 64 smaller shocks form February 2002 to May 2003, recorded by Heyuan station, is calculated by using peak acceleration (a_p), peak velocity (v_p) and peak displacement (d_p). We found that error of τ_(0v) and τ_(0d) mainly came from seismic moment M_0. So, if M_0 cannot be calculated from source spectrum, the error of τ_0, calculated by use of peak acceleration, was small. Shear stress provided the specific physical foundation for analyzing the earthquake tendency by use of magnitude sequence. When many shocks with high magnitude occurred, the stress field is situated in a reinforced background, which reminds possibility of lager earthquake occurrence, or vise verse. A linear correlation was got by means of formula analyzing and data fitting between lg(τ_0) and M_L. Therefore, the efficiency of earthquake prediction seems to be basically same when compared the magnitude with shear stress sequence. But the method of calculating τ_0 is complicated, and its error probability is also higher than that of magnitude calculation.
The environment shear stress τ_0 for 64 smaller shocks form February 2002 to May 2003, recorded by Heyuan station, is calculated by using peak acceleration (a_p), peak velocity (v_p) and peak displacement (d_p). We found that error of τ_(0v) and τ_(0d) mainly came from seismic moment M_0. So, if M_0 cannot be calculated from source spectrum, the error of τ_0, calculated by use of peak acceleration, was small. Shear stress provided the specific physical foundation for analyzing the earthquake tendency by use of magnitude sequence. When many shocks with high magnitude occurred, the stress field is situated in a reinforced background, which reminds possibility of lager earthquake occurrence, or vise verse. A linear correlation was got by means of formula analyzing and data fitting between lg(τ_0) and M_L. Therefore, the efficiency of earthquake prediction seems to be basically same when compared the magnitude with shear stress sequence. But the method of calculating τ_0 is complicated, and its error probability is also higher than that of magnitude calculation.
引文
[1]陈培善, Duda S J.峰值速度和加速度对环境应力场的依赖性[ J].地球物理学报,1993,36(2):180-191.
[2]白彤霞,陈培善.利用北京数字化台网资料估计首都圈地区的构造环境应力场[ J].华南地震,1998,18(1):9-14.
[3]陈培善,白彤霞,肖磊.根据环境应力场寻找中国大陆地区的潜在震源[ J].地震学报,1995,17(3):294-198.
[4]陈培善,肖磊,白彤霞,等.唐山地震序列的环境应力场[J].地震学报,1994,16(4):440-447.
[5]王绍晋,龙晓帆.云南三次强震前后环境剪应力场动态变化[J].地震学报,1999,21(2):150-155.
[6]王绍晋,秦嘉政,黄毓珍.环境剪应力场动态变化在施甸地震中短期预测中的应用[J].地震研究,2002,25(3):232-239.
[7]闻则刚,胡秀敏,何?琳,等.应用数字地震台网资料求解广东地区的环境剪应力场[J].华南地震,2000,20(4):54-59.
[8]叶秀薇,闻则刚,杨马陵,等.广东地区4级左右地震前环境剪应力场的变化[J].地震地磁观测与研究,2003,22(6):26-31.
[9]康英,郑斯华,刘杰,等.中小地震震源参数的求解及其相似关系[ J].华南地震,2004,24(2):11-21.
[10]中国地震局.地震及前兆数字观测技术规范(试行):地震观测部分[M].北京:地震出版社,2001.
[2]白彤霞,陈培善.利用北京数字化台网资料估计首都圈地区的构造环境应力场[ J].华南地震,1998,18(1):9-14.
[3]陈培善,白彤霞,肖磊.根据环境应力场寻找中国大陆地区的潜在震源[ J].地震学报,1995,17(3):294-198.
[4]陈培善,肖磊,白彤霞,等.唐山地震序列的环境应力场[J].地震学报,1994,16(4):440-447.
[5]王绍晋,龙晓帆.云南三次强震前后环境剪应力场动态变化[J].地震学报,1999,21(2):150-155.
[6]王绍晋,秦嘉政,黄毓珍.环境剪应力场动态变化在施甸地震中短期预测中的应用[J].地震研究,2002,25(3):232-239.
[7]闻则刚,胡秀敏,何?琳,等.应用数字地震台网资料求解广东地区的环境剪应力场[J].华南地震,2000,20(4):54-59.
[8]叶秀薇,闻则刚,杨马陵,等.广东地区4级左右地震前环境剪应力场的变化[J].地震地磁观测与研究,2003,22(6):26-31.
[9]康英,郑斯华,刘杰,等.中小地震震源参数的求解及其相似关系[ J].华南地震,2004,24(2):11-21.
[10]中国地震局.地震及前兆数字观测技术规范(试行):地震观测部分[M].北京:地震出版社,2001.
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