Changes in the orbit of the earth caused the ice sheets to spread across Canada.
Explanation:
urban areas are mostly characterised by high population advanced technology and basic amenities. The population helps to increase productivity which leads to economic development, employment opportunities that promotes increase in standard of living which in turn helps economic development.
Claiming it as a historic item (which it is) through a document prevents common people to be affiliated with harming it. So by saying it is of significant history, citizens and tourists will not be able to do anything to jeopardize the natural landmark
