某些震源问题的讨论
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摘要
震前预滑是预报大震的物理基础之一。在强的构造压力作用下形成的震源，预滑较显著。在构造引张作用下形成的震源，预滑易和发震本身紧连在一起。大地震（Ｍ≥７）发生时在地表形成的错动可分三种类型：第一种是在震中区局部地段有错动；第二种是在地表与震源长度相当的地段有错动但中间部位位移较大；第三种是在地表与震源长度相当的地段有错动但位移大小到处几乎相当。按照组合模式，可将地震前兆分为震源区前兆、调整单元和调整场区前兆、震源外围更大范围区域应力场前兆。对地震三要素的预报来说，最重要是前二种前兆，第三种前兆可作参考。
Pre-earthquake creeping is a physical base for predicting big earthquake. For the earthquake source formed under high tectonic pressure, the pre-earthquake creeping is more obvious. For the earthquake source formed under tectonic tension, the pre-- earthquake creeping is favorable to closely join with the dislocation of earthquake occurrence time. When big earthquakes (M≥7) occur,their coseismic faults on earth's surface are classified as three types: ① The coseismic faults only appear in a small segment in epicen- ter area. ② It appear in a length, which is equal to the fault in earthquake source, but its displacement is bigger in middle part in earth's surface. ③ The length of coseismic fault is equal to that in earthquake source, and its displacement is almost same in whole length on earth's surface. According to the combination model, area displaying precursors may be divided as that: the precursors display in source region, in adjustmental elements or adjustmental field, and in more wide extent around the source which is corresponding to regional stress field. For predicting earthquake's time, location and magnitude, the first two are the most important, the third can be referred for prediction.
Pre-earthquake creeping is a physical base for predicting big earthquake. For the earthquake source formed under high tectonic pressure, the pre-earthquake creeping is more obvious. For the earthquake source formed under tectonic tension, the pre-- earthquake creeping is favorable to closely join with the dislocation of earthquake occurrence time. When big earthquakes (M≥7) occur,their coseismic faults on earth's surface are classified as three types: ① The coseismic faults only appear in a small segment in epicen- ter area. ② It appear in a length, which is equal to the fault in earthquake source, but its displacement is bigger in middle part in earth's surface. ③ The length of coseismic fault is equal to that in earthquake source, and its displacement is almost same in whole length on earth's surface. According to the combination model, area displaying precursors may be divided as that: the precursors display in source region, in adjustmental elements or adjustmental field, and in more wide extent around the source which is corresponding to regional stress field. For predicting earthquake's time, location and magnitude, the first two are the most important, the third can be referred for prediction.
引文
[1]孙吉主,唐春安断层地震孕震的椭圆形区域及其前兆规律[J].地震,1996,16(4):355-362
[2]郭增建,秦保燕,冯学才.从震源孕育模式讨论大震前地下水的变化[J].地球物理学报,1974,17(2):99-105
[3]兰州地震大队关于震源问题的讨论[J].地震战线,1971,(8):36-37.
[4]郭增建,秦保燕,李海华,等.磁暴和天气韵律与发震时间[J].地震战线,1977,(3):26-29.
[5] Stuart W D. Strain softening instability model for the Sen Fernando earthquake [J]. Science, 1979, 203, (4383):907-910.
[6]殷有泉,张宏.断裂带内介质的软化特征和地震的非稳定模型[J].地震学报,1984,6(2):135-145.
[7]牛志仁,陈党民含有一粗糙面的走滑断层的滑动弱化不稳定性[J].地震学报,1987,9(3):253-264
[8]陈.地壳岩石的力学性能──理论基础与实验方法[M].北京地震出版社,1988.
[9]张国民,傅征祥.由岩体失稳讨论地震前兆的复杂性[J].地震研究,1990,13(3):215-222
[10]郭增建,秦保燕,徐文耀,等,震源孕育模式的初步讨论[J].地球物理学报,1973,16:43-48
[11]郭增建.地震成因与地震预报[M].北京:地震出版社,1991.
[12]周光.地震[M].北京:地质出版社,1956.
[13]郭增建,秦保燕,徐文耀唐山大震成因初探[J].自然科学争鸣,1977,(5):34-37.
[14]郭增建,秦保燕.震源组合模式与地震预报[J].地震科学研究,1979,(创刊号):49-51
[15]郭增建,秦保燕,张远孚,等.从水平力和垂直力的相互作用讨论我国境内地震的孕育和发生[J].地球物理学报,1977,20(3):242-250.
[16]郭增建,秦保燕,刘江峰.从震源物理观点讨论鄂尔多斯地台的地震稳定性[J].西北地震学报,1985,(增刊):10-12.
[2]郭增建,秦保燕,冯学才.从震源孕育模式讨论大震前地下水的变化[J].地球物理学报,1974,17(2):99-105
[3]兰州地震大队关于震源问题的讨论[J].地震战线,1971,(8):36-37.
[4]郭增建,秦保燕,李海华,等.磁暴和天气韵律与发震时间[J].地震战线,1977,(3):26-29.
[5] Stuart W D. Strain softening instability model for the Sen Fernando earthquake [J]. Science, 1979, 203, (4383):907-910.
[6]殷有泉,张宏.断裂带内介质的软化特征和地震的非稳定模型[J].地震学报,1984,6(2):135-145.
[7]牛志仁,陈党民含有一粗糙面的走滑断层的滑动弱化不稳定性[J].地震学报,1987,9(3):253-264
[8]陈.地壳岩石的力学性能──理论基础与实验方法[M].北京地震出版社,1988.
[9]张国民,傅征祥.由岩体失稳讨论地震前兆的复杂性[J].地震研究,1990,13(3):215-222
[10]郭增建,秦保燕,徐文耀,等,震源孕育模式的初步讨论[J].地球物理学报,1973,16:43-48
[11]郭增建.地震成因与地震预报[M].北京:地震出版社,1991.
[12]周光.地震[M].北京:地质出版社,1956.
[13]郭增建,秦保燕,徐文耀唐山大震成因初探[J].自然科学争鸣,1977,(5):34-37.
[14]郭增建,秦保燕.震源组合模式与地震预报[J].地震科学研究,1979,(创刊号):49-51
[15]郭增建,秦保燕,张远孚,等.从水平力和垂直力的相互作用讨论我国境内地震的孕育和发生[J].地球物理学报,1977,20(3):242-250.
[16]郭增建,秦保燕,刘江峰.从震源物理观点讨论鄂尔多斯地台的地震稳定性[J].西北地震学报,1985,(增刊):10-12.
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