CAJ | 학술논문

智利 MS 8．8特大地震在甘肃数字测震台网记录的最大震中距达179．7°，通过读取该地震初至震相的观测走时，计算该震相的平均观测慢度为4．104 s／°，与 Pdif 震相的理论慢度4．439 s／°基本一致．研究结果表明：由于甘肃数字测震台网和甘东南野外观测流动台阵独特的地理位置，记录到了至今全球最大震中距（179．7°）的核幔界面衍射波 Pdif 震相；Pdif 震相起始观测走时明显滞后于 IASP91理论走时；核幔界面复杂的形态对不同方位传播的 Pdif 震相观测走时产生了一定的影响．
지리 MS 8．8특대지진재감숙수자측진태망기록적최대진중거체179．7°，통과독취해지진초지진상적관측주시，계산해진상적평균관측만도위4．104 s／°，여 Pdif 진상적이론만도4．439 s／°기본일치．연구결과표명：유우감숙수자측진태망화감동남야외관측류동태진독특적지리위치，기록도료지금전구최대진중거（179．7°）적핵만계면연사파 Pdif 진상；Pdif 진상기시관측주시명현체후우 IASP91이론주시；핵만계면복잡적형태대불동방위전파적 Pdif 진상관측주시산생료일정적영향．
The largest epicentral distance of Chile MS 8.8 earthquake reaches 179.7°recorded by Gansu Digital Seismic Network.Through artificially reading observational first-arrival travel time of the Chile earthquake,we calculated the average observational slowness of the first arrival phase is 4.104 s/°,which is basically consistent with theoretical slowness (4.439 s/°)of Pdif .The results show that the Pdif can recorded at the epicentral distance 179.7°due to particu-lar location of Gansu Digital Seismic Network and southeastern Gansu tempora-ry observation array;the origin observed travel time lags behind the IASP91 theoretical travel time obviously;and Pdif travel times observed from different directions are affected by complex morphology of the core-mantle boundary.