丽江7.0级地震前跨断层形变累积率的变化特征
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摘要
通过对丽江 7 0级地震前跨断层短水准、短基线资料断层形变累积率的计算分析 ,表明丽江地震前跨断层形变累积率在空间分布上及演化过程中有一定的分布特征。以丽江—剑川断裂为界 ,其西部震中附近的断层形变累积率相对较低 ,而其东部周围的则较高 ,且震前存在累积率减小的调整过程。由此可见 ,地震不一定发生在形变累积率高的地区 ,而通常发生在多年形变累积率空间分布差异性显著的地区。通过多场地断层形变累积率的计算 ,分析其空间分布特征及演变 ,结合其它手段资料 ,对地震中、长期危险区的判定及中短期危险性的判定有重要的参考意义
According to the analyzed results,the cross-fault cumulative prercentage of deformation is proved to have some characterists in space distribution as well as in the preparing process before Lijiang Earthquake.To the east part of Lijiang-jianchuan Fault (namely the epicentral area of Lijiang Earthquake), The cumulative percentage is relatively low. But to the east part of it, the cumulative percentage is high.There was an adjusting process in which the cumulative percentage was going down before the earthquake occurred. So it is obvious that the earthquakes do not always occur in the high cumulative percentage area but normally occur in the areas in which the distribution of the cumulative percentage is distinct. So, through calculation of multi-field cumulative percentage of deformation of fault, one can analyze the characteristics of cumulative percentage in space distribution and in evolution. Together with data got by other surveying methods,the characteristics of cumulative percentage can be referential to the discrimination of mid-long term earthquake risk area and the mid-short term earthquake area.
According to the analyzed results,the cross-fault cumulative prercentage of deformation is proved to have some characterists in space distribution as well as in the preparing process before Lijiang Earthquake.To the east part of Lijiang-jianchuan Fault (namely the epicentral area of Lijiang Earthquake), The cumulative percentage is relatively low. But to the east part of it, the cumulative percentage is high.There was an adjusting process in which the cumulative percentage was going down before the earthquake occurred. So it is obvious that the earthquakes do not always occur in the high cumulative percentage area but normally occur in the areas in which the distribution of the cumulative percentage is distinct. So, through calculation of multi-field cumulative percentage of deformation of fault, one can analyze the characteristics of cumulative percentage in space distribution and in evolution. Together with data got by other surveying methods,the characteristics of cumulative percentage can be referential to the discrimination of mid-long term earthquake risk area and the mid-short term earthquake area.
引文
[1]江在森,丁平,王双绪,等.中国西部大地形变监测与地震预报[M].北京:地震出版社,2001,40-46.
[2]张兴华,宋金玲,王琼伟,等.云南中西部地区现今构造活动与现今构造形变应力场[J].地震研究,2001,24(4).
[3]张兵,江在森,胡斌,等.断层形变数字特征及演化研究—形变趋势累积率DC值[A].见:中国地震学会第七次学术大会论文摘要集[C].北京:地震出版社,1998
[2]张兴华,宋金玲,王琼伟,等.云南中西部地区现今构造活动与现今构造形变应力场[J].地震研究,2001,24(4).
[3]张兵,江在森,胡斌,等.断层形变数字特征及演化研究—形变趋势累积率DC值[A].见:中国地震学会第七次学术大会论文摘要集[C].北京:地震出版社,1998
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