利用滑动速率、古地震资料估算走滑断裂的粘滑及蠕滑量的方法
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摘要
断层走滑包括粘滑和蠕滑，前者是伴有强震发生的快速运动，后者则是一种缓慢的无震稳滑运动。这２ 种运动常随时间交替出现，共同构成了断层的基本运动方式。在利用断层滑动速率讨论大震重复率的问题中，人们最关心的问题则是如何从总滑动量中分辨和划分出其中所包含的粘滑和蠕滑量，特别是对蠕滑量的划分，因为它直接影响着大震重复率的正确性。笔者在野外考察的基础上，对昌马活动断裂的位移量进行了分级，确定出昌马断裂带全新世以来的水平滑动量大致可划分为５个级别：３１～４１ ｍ ；２５～３１ ｍ ； １５～２２ ｍ ； ８～１３ ｍ ；１～５．５ ｍ ，同时依据古地震学方法并结合１４Ｃ断代法及断层崖形成年代的数学模拟计算，求得全新世以来在昌马断裂带上共发生５ 次古地震事件。在上述２ 项资料确定的基础上，进一步对昌马断裂带的粘滑及蠕滑量进行了划分，并给出了它们随时间的变化情况
The strike slip of a fault includes stick slip and creep slip.The former is a kind of speedy movement with the occurrence of a strong earthquake,and the latter is a kind of slow,steady slipping movement without earthquakes.The two kinds of movement usually happen in turn as time goes on,forming the basic moving ways of the fault together. When using the slipping rate of a fault to discuss the recurrence rate of large earthquakes,people most care for the question how to identify and divide stick slip amount and creep slip amount from total slip amount,especially to divide creep slip amount,since it directly effect the accuracy of the recurrence rate of large events.Through field investigation for Changme active fault zone,the author thought that the horizontal slipping amount of Changma Fault Zone since Recent can be divided into 5 scales:31~41 m,25~31 m,15~22 m,8~13 m,1~5.5 m.Based on paleoseismological method,carbon 14 dating method and the mathematical simulation calculation of scarp forming age,it is gotten that there have been 5 paleoearthquakes occurring on Changma Fault Zone since Recent.By means of above data,the stick slip amount and creep slip amount of Changma Fault Zone are made a division,and the conditions that they vary with time is given.
The strike slip of a fault includes stick slip and creep slip.The former is a kind of speedy movement with the occurrence of a strong earthquake,and the latter is a kind of slow,steady slipping movement without earthquakes.The two kinds of movement usually happen in turn as time goes on,forming the basic moving ways of the fault together. When using the slipping rate of a fault to discuss the recurrence rate of large earthquakes,people most care for the question how to identify and divide stick slip amount and creep slip amount from total slip amount,especially to divide creep slip amount,since it directly effect the accuracy of the recurrence rate of large events.Through field investigation for Changme active fault zone,the author thought that the horizontal slipping amount of Changma Fault Zone since Recent can be divided into 5 scales:31~41 m,25~31 m,15~22 m,8~13 m,1~5.5 m.Based on paleoseismological method,carbon 14 dating method and the mathematical simulation calculation of scarp forming age,it is gotten that there have been 5 paleoearthquakes occurring on Changma Fault Zone since Recent.By means of above data,the stick slip amount and creep slip amount of Changma Fault Zone are made a division,and the conditions that they vary with time is given.
引文
1 马宗晋,叶 洪,陈树岩等.活动构造基础与工程地震.北京:地震出版社,1992.
2 中国地震局兰州地震研究所.昌马活动断裂带.北京:地震出版社,1992.
3 侯康明,韩有珍,张守杰.断层岩形成年代的数学模拟计算.西北地震学报,1995,17(2):68～75.
4 丁国瑜.第四纪断层上断裂活动的群集及迁移现象.第四纪研究,1989,(1):36～47.
5 侯康明,郭敬信,侯珍清等.昌马断裂带水平断错与强震重复率估计.中国地震,1990,6(3):70～78.
6 侯康明,袁道阳,孟万辉.走滑断裂粘滑、蠕滑作用形成的地质地貌特征.地震地质,1995,17(3):253～258.
7 Wallace,R.E,Earthquake intervalon the San Andreas Fault.GeolSoc Am Bull,1977,88(10):1276.
2 中国地震局兰州地震研究所.昌马活动断裂带.北京:地震出版社,1992.
3 侯康明,韩有珍,张守杰.断层岩形成年代的数学模拟计算.西北地震学报,1995,17(2):68～75.
4 丁国瑜.第四纪断层上断裂活动的群集及迁移现象.第四纪研究,1989,(1):36～47.
5 侯康明,郭敬信,侯珍清等.昌马断裂带水平断错与强震重复率估计.中国地震,1990,6(3):70～78.
6 侯康明,袁道阳,孟万辉.走滑断裂粘滑、蠕滑作用形成的地质地貌特征.地震地质,1995,17(3):253～258.
7 Wallace,R.E,Earthquake intervalon the San Andreas Fault.GeolSoc Am Bull,1977,88(10):1276.
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