Across
1
Mountain that can erupt with lava
5
Distance north or south of equator
6
Vast body of salt water
7
Wearing away of land by water or wind
Down
2
Deep narrow valley with steep sides
3
Large area covered with trees
4
Region surrounding the North Pole
8
Seasonal heavy rainfall
9
Large slow-moving mass of ice
10
Largest river in South America
11
Height above sea level
12
Ridge of rock or coral near the surface