关键词: 智利地震, DEMETER, IDP通量, 高能粒子, 重访轨道

Abstract: Based on the IDP data from French DEMETER satellite,the global distribution is shown,which corresponds to three precipitation zones:auroral precipitation zone,mid-high latitude precipitation zone and South Antarctic precipitation zone.Then the Chili earthquake with M8.8 on February 27,2010 is taken as an example.The IDP fluxes from repeated orbits are compared and the results show that there is a clear enhancement on February 26,just one day ahead of the Chili earthquake.In the south zone with L = 2.1 ～ 2.7,the flux on February 26 is higher than that on other days before.While in the north zone with L = 2.1 ～ 2.7,there is no clear change in the day time but a great enhancement during the night,which is close to the earthquake occurrence time.At the same time,the flux on February 26 over the epicenter is far lower than that on other days before during the day time while it reaches the peak at night.

Key words: Chili earthquake, DEMETER, IDP flux, energetic particles, repeated orbits