Across
1
Largest river in South America
4
Ridge of rock or coral near the surface
6
Wearing away of land by water or wind
7
Physical features of land
11
Cold treeless Arctic plain
Down
2
Vast body of salt water
3
Large slow-moving mass of ice
5
One of seven major landmasses
8
Low area between mountains
9
Half of the Earth
10
Narrow sea inlet between cliffs