Across
1
Low-lying land surrounded by higher ground
4
Ocean between Americas and Europe/Africa
5
Height above sea level
6
Imaginary line around the middle of Earth
7
Largest ocean on Earth
9
Seasonal heavy rainfall
13
Low area between mountains
Down
2
Flat grassland in tropical regions
3
Total number of people in an area
8
Mountain that can erupt with lava
10
Large natural stream of water
11
Region between the two tropic lines
12
Piece of land jutting into the sea