摘要
利用朝鲜半岛东南部地区浅层地应力数据,给出区域现今应力状态的分布特征及其与断层分布的关系。地应力数据表明,区域最大主压应力呈ENE-WSW到NE-SW向,这与地震震源机制解及欧亚板块东部构造应力方向的一阶模式一致。或许是受到断层的影响,现今应力张量在大小和方向上表现出不均匀性。区域水平主应力变化较为一致,而垂向则变化较大。应力场的大小受区域断层多少的影响,断层越多应力越小,这表明断层应力释放或许是造成低应力的主要原因之一。为了验证这种假设的正确性,我们对第四纪活动断层与现今应力场的关系进行分析。在现今应力状态下,断层剪应力与正应力比值较高,这与区域大部分断层以走滑为主是一致的,这意味着断层的活动可以维持当前的应力场。
引文
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