Across
1
Low area between mountains
4
Imaginary line around the middle of Earth
6
Largest river in South America
7
Vast body of salt water
9
Mountain that can erupt with lava
10
Large natural elevation of earth
Down
2
Height above sea level
3
Long-term weather patterns of an area
5
Piece of land jutting into the sea
8
Total number of people in an area