有限差分法合成地震图中的网格频散
-
摘要: 用有限差分法合成地震图时, 有限大小的地球模型必须分成许多小网格。如果和源信号的波长相比, 格子太大, 那么随着走时的增加, 波将产生频散。这一现象被称为网格频散, 也就是不同频率的波速度也不相同, 频率较高的信号比频率较低的信号速度慢。此时, 随着走时的增加, 信号将产生一个显着的尾区。这一现象将在如下情况发生：①网格间距太大: ②采样率太大: 或③震源波长和网格大小相比太短。换言之, 用有限差分法合成地震图的一个重要参数是, 每个震源信号波长上网格的点数。本文的工作表明：当P-SV波对经有限差分的弹性模型传播时, 源函数的频率对网格频散有很大的影响。文中所用的二维弹性模型包括：①正断层: ②半空间上单层模型。结果表明：用有限差分法合成地震图时, 如果对于介质的最低速度, 与震源信号的半功率频率相应的一个波长和格点间距之比超过10时, 网格频散将减小到满意的水平。
-
-
[1] Alford, R. M., Kelly, K. R. and Boore, D. M., 1974. Accuracy of finite——difference modeling of the acoustic wave equation. Geophysics, 39, 834——842.
[2] Alterman, Z. S and Loewenthal, D., 1970. Seismic waves in a quarter and three quarter plane. Geophys. J. R. astr. Soc., 20, 101——126.
[3] Boore, D. M., 1969. Finite——Difference Solutions to the Equatirnu of Elastic Wave Propagation, with Applications to Lone Waves (?uer Ih'pping Interfaces. Ph. D., Thesis, M. I. T., Mass.
[4] Boore, D. M., 1970. Love waves in nonuniform wave guides: Finite——difference calculations. J. Geophys. Res., 75, 1512——1527.
[5] Boore, D. M., 1972. Finite——difference methods for seismic wave propagation in heterogeneous materials. In: Alder, B., Fernback, S. and Rotenberg, M. (editors), Methods in Computational Physics, Vol. if, Academic Press.
[6] Clayton. R. and Engquist, B., 1977. Absorbing boundary conditions for acoustic and elastic wave equations. Bull. Sei.s. Soc. Amer., 67, 1529——1540.
[7] Javaherian, A., 1982. Eliminatirm of Spuriatts Re_flecti}na from Finite——Difference Synthetic Seismograms with Applicutitnts to the San Andrews Fault Zone. Ph. D. Thesis, University of Texas at Dallas.
[8] Kelly, K. R., Ward. R. W., Treitlel, S. and Alford, M., 1976. Synthetic seismograms: A finite——difference approach. Geophysics, 41, 2——27.[1] Alford, R. M., Kelly, K. R. and Boore, D. M., 1974. Accuracy of finite——difference modeling of the acoustic wave equation. Geophysics, 39, 834——842.
[2] Alterman, Z. S and Loewenthal, D., 1970. Seismic waves in a quarter and three quarter plane. Geophys. J. R. astr. Soc., 20, 101——126.
[3] Boore, D. M., 1969. Finite——Difference Solutions to the Equatirnu of Elastic Wave Propagation, with Applications to Lone Waves (?uer Ih'pping Interfaces. Ph. D., Thesis, M. I. T., Mass.
[4] Boore, D. M., 1970. Love waves in nonuniform wave guides: Finite——difference calculations. J. Geophys. Res., 75, 1512——1527.
[5] Boore, D. M., 1972. Finite——difference methods for seismic wave propagation in heterogeneous materials. In: Alder, B., Fernback, S. and Rotenberg, M. (editors), Methods in Computational Physics, Vol. if, Academic Press.
[6] Clayton. R. and Engquist, B., 1977. Absorbing boundary conditions for acoustic and elastic wave equations. Bull. Sei.s. Soc. Amer., 67, 1529——1540.
[7] Javaherian, A., 1982. Eliminatirm of Spuriatts Re_flecti}na from Finite——Difference Synthetic Seismograms with Applicutitnts to the San Andrews Fault Zone. Ph. D. Thesis, University of Texas at Dallas.
[8] Kelly, K. R., Ward. R. W., Treitlel, S. and Alford, M., 1976. Synthetic seismograms: A finite——difference approach. Geophysics, 41, 2——27. -
期刊类型引用(8)
1. 苏慧，崔清辉，李国辉，尹迪，周元泽. 基于波形拟合的日本南部及琉球岛弧下方滞留板片的形态结构研究. 地震学报. 2025(01): 37-53 . 
本站查看
2. 赵一帆，王毅. 基于三重震相波形模拟的东北亚地区上地幔S波速度结构研究. 物探化探计算技术. 2024(02): 137-145 . 百度学术
3. 崔冉，周元泽. 地震波三重震相在地幔转换区结构研究中的应用. 地震地磁观测与研究. 2024(05): 11-19 . 百度学术
4. 崔冉，周元泽，苏慧，崔清辉. 东天山地幔过渡带及660km间断面P波速度结构及其对岩石圈拆沉的启示. 中国地震. 2024(04): 752-765 . 百度学术
5. 李国辉，白玲，周元泽，崔清辉. 地幔过渡带顶部低速层地震学研究进展. 地球物理学进展. 2018(04): 1366-1373 . 百度学术
6. WU Xiaoyang，XING Junhui，LI Chaoyang，LIU Xinzhe，YANG Kai，CHEN Hongyan，GONG Wei. Application of Geoid Anomalies to the Tectonic Research in the East Asian Continental Margin. Journal of Ocean University of China. 2018(04): 811-822 . 必应学术
7. 崔辉辉，周元泽，石耀霖，王晓冉，李国辉. 华北克拉通东部滞留板块下方低速异常的地震三重震相探测. 地球物理学报. 2016(04): 1309-1320 . 百度学术
8. 崔辉辉，周元泽. 基于三重震相方法探测日本海俯冲区地幔转换带的速度结构. 地震学报. 2016(05): 659-670+813 . 本站查看
其他类型引用(5)
计量
- 文章访问数: 2178
- HTML全文浏览量: 36
- PDF下载量: 389
- 被引次数: 13
下载:
