A shortage of food that results in widespread hunger is called famine.
The journals were based upon the field diaries that explorers were required to keep by the Colonial Office. The explorers' field diaries and journals were also of vital importance for the information they contained about possible economic benefits that could be derived from the land.
From rocks being added together over time
I'm assuming you meant subsistence farming? If so then yes, it would be a large problem because they would then not have enough food to feed themselves.
A reef than surrounds a volcanic island is an : Atoll
Atoll usually takes shapes in a form of ring that surround the areas of volcanic island that consist of corals. It usually only exist in warm waters, so volcanic islands will provide perfect environment for the corals
hope this helps<span />
