Sentences with phrase «subsurface oxygen depletion»

However, it remains a major scientific challenge to model and project the changes of the magnitude and intensity of subsurface oxygen depletion because it depends on changes in ocean circulation, rates of de-nitrification, and nutrient runoff from land, and because global data coverage for chemical and biological parameters remains poor.

If you look at the last 65 million years, in the so - called Cenozoic era, I don't think there are any examples of globally widespread subsurface oxygen depletion.