Total electron content [TEC] anomaly in the ionosphere over Peru the night before M6.4 – 98km WNW of Camana, Peru 2017-07-18 02:05:19 UTC at a depth of 44.1 km. 06:30:00 UTC, 07/17/2017. I also posted an image without the anomaly for comparative purposes. https://plus.google.com/u/0/117300779230803580292/posts/7MN1KtmKPYE
