CAJ | 학술논문

根据三峡与邻近地区实际天然地震数据，利用GMT软件绘制出三峡地区两次地震的震源机制解。绘制出了三峡地区1964年以来地震震中分布情况，以及频率变化。震源机制解以及三峡与邻近地区断层资料显示出该地区受到西藏块体、四川盆地、川滇块体与鄂尔多斯地块的共同挤压作用，三峡及邻区的现今水平构造应力场的主压应力轴为北东东向，是喜马拉雅期构造应力场的继续。近东西向的向东移动显示出该地区可能为青藏高原地幔物质向东“逃逸”的通道之一。根据水库蓄水前后震源机制解资料反映的震源机制变化，认为蓄水对于三峡及邻区应力场在垂向上有一定的影响。
근거삼협여린근지구실제천연지진수거，이용GMT연건회제출삼협지구량차지진적진원궤제해。회제출료삼협지구1964년이래지진진중분포정황，이급빈솔변화。진원궤제해이급삼협여린근지구단층자료현시출해지구수도서장괴체、사천분지、천전괴체여악이다사지괴적공동제압작용，삼협급린구적현금수평구조응력장적주압응력축위북동동향，시희마랍아기구조응력장적계속。근동서향적향동이동현시출해지구가능위청장고원지만물질향동“도일”적통도지일。근거수고축수전후진원궤제해자료반영적진원궤제변화，인위축수대우삼협급린구응력장재수향상유일정적영향。
According to the seismic data of the three gorges and adjacent area, focal mechanism solutions of the three gorges region is drawn by GMT software. Draw earthquake epicenter distribution and frequency changes since 1964.Focalmechanism solution and the three gorges and nearby area fault data shows nowadays the horizontal tectonic stress field in the three gorges and its adjacent area takes NE orientation as the principal compressive stress axes, because of the region block in Tibet, the Sichuan basin, Sichuan and Yunnan block and Ordos massif of squeezed together. Scholars deem it a continuation of the Himalayan tectonic stress field. Nearly east-west eastward movement shows that, there may exist a channel to the east in this region for the mantle material "escape" of the Qinghai-Tibet plateau. According to the focal mechanism solution, the focal mechanism was changed before and after the reservoir impoundment, shows impoundment has a certain influence on the stress field in three gorges and its adjacent area, major in vertical direction.