Most of them are very short lived (think seconds at most), but they can be as long as a few hours. No part of the Earth will really be 'safe' for humans in sens

Most of them are very short lived (think seconds at most), but they can be as long as a few hours. No part of the Earth will really be 'safe' for humans in sense of 'unaffected' like other places could be, but yeah, lots of people would only suffer from the after effects.