The density of the mineral is 2.1 g/mL
Older and denser oceanic lithosphere is constantly subducting into the mantle at a rate equal to new lithosphere creation at divergent boundaries.
i can only give an answer to number 1.
land. because most disasters that occur are caused by either air or water. air pollution or flood.

The plan covers the on-going protection and management of the natural and cultural values of the park, particularly through the management of fire, the control of weeds and feral animals and responding to and mitigating the impacts of climate change.