中国物理B ›› 2001, Vol. 10 ›› Issue (10): 914-917.doi: 10.1088/1009-1963/10/10/306

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THE DYNAMIC FRICTION TERM IN THE SPRING-BLOCK MODELS FOR EARTHQUAKES: A CONSTRAINT FROM SEISMIC MOMENT AND ENERGY CATALOGUE

吴忠良   

  1. Institute of Geophysics, China Seismological Bureau, Beijing 100081, China
  • 收稿日期:2001-02-25 修回日期:2001-04-06 出版日期:2001-10-15 发布日期:2005-06-12
  • 基金资助:
    Project supported by the State Key Development Program for Basic Research of China (Grant No. 1998040705), by the National Natural Science Foundation of China (Grant No. 49725410), and by the LDEO, Columbia University.

THE DYNAMIC FRICTION TERM IN THE SPRING-BLOCK MODELS FOR EARTHQUAKES: A CONSTRAINT FROM SEISMIC MOMENT AND ENERGY CATALOGUE

Wu Zhong-liang (吴忠良)   

  1. Institute of Geophysics, China Seismological Bureau, Beijing 100081, China
  • Received:2001-02-25 Revised:2001-04-06 Online:2001-10-15 Published:2005-06-12
  • Supported by:
    Project supported by the State Key Development Program for Basic Research of China (Grant No. 1998040705), by the National Natural Science Foundation of China (Grant No. 49725410), and by the LDEO, Columbia University.

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摘要： In the spring-block models of earthquakes, one of the key factors is the dynamic friction term which determines the complexity of the faulting process. Generally, two kinds of friction, namely velocity-dependent friction and slip-dependent friction, are used in the modelling. But until now there has still been a lack of information on which kind of friction term is more suitable for modelling the phenomenology of earthquakes. Based on the numerical studies of Shaw (1998 Bull. Seismol. Soc. Am. 88 1457), we have examined the ratio of the broadband radiated energy and the scalar seismic moment of shallow earthquakes worldwide from 1987 to 1998. The result shows that for earthquakes with strike-slip mechanisms, velocity-dependent friction seems to be predominant, while for thrust and normal events, slip-dependent friction seems predominant. This suggests that in the spring-block models for earthquakes, the type of focal mechanism has to be accounted for, and different types of earthquakes require different dynamic friction terms in the corresponding spring-block model.

Abstract: In the spring-block models of earthquakes, one of the key factors is the dynamic friction term which determines the complexity of the faulting process. Generally, two kinds of friction, namely velocity-dependent friction and slip-dependent friction, are used in the modelling. But until now there has still been a lack of information on which kind of friction term is more suitable for modelling the phenomenology of earthquakes. Based on the numerical studies of Shaw (1998 Bull. Seismol. Soc. Am. 88 1457), we have examined the ratio of the broadband radiated energy and the scalar seismic moment of shallow earthquakes worldwide from 1987 to 1998. The result shows that for earthquakes with strike-slip mechanisms, velocity-dependent friction seems to be predominant, while for thrust and normal events, slip-dependent friction seems predominant. This suggests that in the spring-block models for earthquakes, the type of focal mechanism has to be accounted for, and different types of earthquakes require different dynamic friction terms in the corresponding spring-block model.

Key words: Burridge-Knopoff spring-block model, dynamic friction, earthquake catalogue, earthquake energy, seismic moment

中图分类号:  (Earthquakes)

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