Across
1
Cold treeless Arctic plain
4
Wearing away of land by water or wind
5
Largest river in South America
6
Piece of land jutting into the sea
9
Tool for finding directions
Down
1
Region near the equator
2
Mountain that can erupt with lava
3
Total number of people in an area
7
Low-lying land surrounded by higher ground
8
Dry land with little rainfall