Answer:
As one plate subducts, it sets up convection currents in the upper mantle that 'exert a net trenchward pull'
Explanation:
Scientists can't be sure about the early atmosphere and can only draw evidence from other sources. For example, volcanoes release high quantities of carbon dioxide. Iron-based compounds are present in very old rocks that could only have formed if there was little or no oxygen at the time.
Traditional management techniques include pollarding . This technique encourages new growth, and maintains the trees for future generations. It is a form of sustainable management in the woodland. Pollarding also encourages birds to nest.
Well, Alaska has one, (Kenai Fjords, excellent place) there are plenty in Norway, if that's what you're asking.
