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地震 ›› 1999, Vol. 19 ›› Issue (1): 26-32.

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中国大陆地壳应变能密度年变化率图像与强震活动关系的初步探讨

张东宁, 许忠淮   

  1. 中国北京 100081 中国地震局地球物理研究所
  • 收稿日期:1998-06-17 修回日期:1998-07-18 出版日期:1999-01-31 发布日期:2022-09-19
  • 作者简介:张东宁,男,1963年6月出生.副研究员,1993年获博士学位,主要从事地球动力学问题的数值模拟工作。
  • 基金资助:
    中国地震局“九五”科研攻关项目(95-04),中国地震局地球物理研究所论著(98A02071)

ANNUAL CHANGING RATE OF THE CRUSTAL STRAIN­ENERGY DENSITY AND ACTIVITY OF STRONG EARTHQUAKES IN CHINA'S CONTINENT

Zhang Dongning, Xu Zhonghuai   

  1. Institute of Geophysics, CSB, Beijing 100081, China
  • Received:1998-06-17 Revised:1998-07-18 Online:1999-01-31 Published:2022-09-19

摘要: 以现代构造应力场和地壳运动的观测结果为约束条件,利用有限元方法计算了中国大陆 地壳应变能密度年变化率。 三维有限元模型采用粘弹性本构关系,包含了中国大陆主要活动断裂带。在青藏高原考虑了因高海拔地势蓄集的附加重力势能和地壳山根浮力作用。边界条件主 要考虑了印度洋板块和太平洋板块对欧亚板块的挤压作用。把模拟结果与强震活动的时间和空间分布特征相比较。 地壳应变能密度年变化率正、负值过渡带分别对应着龙门山断裂带、燕山 阴山构造带、天山构造带、鲜水河小江断裂带、红河断裂带、鄂尔多斯周边断裂带。 而这些构造带均是历史上强地震的多发带。 由应变能密度年变化率的数值估计,中国西部地震活动带的强 震重复周期应该在250年左右。 而华北中、南部地区的强震重复周期要长得多。

关键词: 中国大陆, 地壳应变能密度, 年变化率, 强震活动, 有限元

Abstract: The annual changing rates of the crustal strain energy density in China's continent are calculated by using the finite element method, and the calculation is constrained with the tectonic stress field and the GPS results of crustal motion. The numerical model is con­structed with 3 D elasto-viscous body, and some large-scale active faults are involved. Gravity and buoyancy forces are considered in Tibetan plateau. Some boundary loading is applied as convergence of Eurasia plate with Pacific plate and Indian plate. The calculation results are compared with the distribution map of strong earthquakes in China. The transi­t1onal zones of the positive and negative strain energy changing rate areas are just corre sponding to Longmenshan fault, Yanshan-Yinshan E W tectonic zone, Tianshan tectonic zoe, Xianshuihe Xiaojiang fault, Hong he fault, faults around Erdos block, which are all the strong earthquake zones in history. The recurrence interval of the strong earthquakes is evaluated with the calculation results of the changing rates of the crustal strain-energy density. The recurrence interval in western China should be 250 years or so, and it may be longer in eastern China.

Key words: China's continent, Crustal strain energy density, Annual changing rate, Strong earthquake activity, Finite element method