チアパス州沖の地震の前震っぽいイベント
M 4.5 2017-09-05 19:17:39 (UTC) 15.079°N 93.877°W 50.2km
　https://earthquake.usgs.gov/earthquakes/eventpage/us2000ag9g
M 4.4 2017-09-07 07:05:24 (UTC) 15.013°N 93.811°W 10.0 km
　https://earthquake.usgs.gov/earthquakes/eventpage/us2000ahe0
M 8.0 2017-09-08 04:49:17 (UTC) 15.029°N 93.807°W 35.0 km　←main shock (TBD)