震级与破裂尺度及位错量关系的讨论

目的探讨现有的一些震级与地表破裂长度及水平位错量间经验关系式的合理性与代表性。方法基于断裂力学理论,通过对各类裂纹开裂过程中应变能释放量与裂纹尺寸、水平位错量间相互关系的分析,讨论前人建立的一些关于震级与地表破裂长度及位错量间的经验关系。结果震级与破裂带长度或水平错动量之间的统计关系式在理论上具有合理性;以青藏高原强震事件参数为基本统计数据,构建了震级、破裂长度与垂直位错的统计关系式,并利用所得关系式用中卫712级地震为例验算,与实际结果相近。结论可以将震级与破裂带长度、错动量等参数通过统计方法建立起某种关系式,但所选用参数以及参数之间的基本关系应当符合断裂力学的一些基本理论及关系原则。

Discussion on relationship between earthquake magnitude, rupture scale and displacement

Aim To differentiate the rationality and representativeness of some existing experiential relations between earthquake magnitude, rupture scale and displacement. Methods Based on fractural mechanics, analyze the relations between releasing quantity of strain energy, crack size and horizontal displacement in rupturing process of cracks, and discuss the rationality and representativeness of some existing experiential relations between earthquake magnitude, rupture scale and displacement. Results Existing experiential relations between earthquake magnitude and rupture scale or displacement were a rationality theoretically, and have some reference value. Based on the reasonableness theoretically, take the strong earthquake event in the Qinghai-Tibet plateau as basic statistic, a statistic relation between earthquake magnitude, rupture scale and vertical displacement has been established, and take 1 709 earthquake with Ms = 7 1/2 in the Zhongwei, Nninxia as a example the relations are used to calculate relational parameters, showing result was close with the actual data. Conclusion It is feasible to establish a relation between earthquake magnitude, rupture scale and displacement by statistics. But in the process the relations first and foremost should consider to elect parameters, and the basic relationship between the parameters ought to accord with basic theory and principle of fractural mechanics.