They pretty much all do by design, it prevents vapours from building up at the top of the tank which is a fire/explosion hazard. It works even better with high

They pretty much all do by design, it prevents vapours from building up at the top of the tank which is a fire/explosion hazard. It works even better with high resolution synthetic aperture radar as you can measure the tank height displacement directly: https://www.iceye.com/blog/daily-analysis-and-forecast-of-global-oil-supplies https://www.iceye.com/blog/daily-analysis-and-forecast-of-gl...