AIR
Climate, Air Pollution

WATER
Lakes, Rivers, Oceans

EARTH
Land Use, Planet Earth

PLANTS
Ecosystems, Flora

TREES
Forests, Tree species

ANIMALS
Fauna, Species data

PEOPLE
Countries, Cultures

OCEANS' GREATEST DEPTHS 
Mariana Trench, Pacific Ocean 35,827ft 
Puerto Rico Trench, Atlantic Ocean 28,232ft 
Java Trench, Indian Ocean 23,376ft
Arctic Basin, Arctic Ocean 16,804ft 

MAJOR SEAS (by size)
South China (2,974,600 sq km) 
Caribbean (2,515,900 sq km) 
Mediterranean (2,510,000 sq km) 
Bering (2,261,100 sq km) 
Gulf of Mexico (1,507,600 sq km) 
Sea of Okhotsk (1,392,100 sq km) 
Sea of Japan or East Sea (1,012,900 sq km) 
Hudson Bay (730,100 sq km) 
East China (664,600 sq km) 
Andaman (564,900 sq km) 
Black (507,900 sq km) 
Red (453,000 sq km) 

MAJOR RIVERS (by length) 
Nile, Africa (6,825 km) 
Amazon, S. America (6,437 km) 
Chang Jiang (Yangtze), Asia (6,380 km) 
Mississippi, N. America (5,971 km) 
Yenisey-Angara, Asia (5,536 km) 
Huang (Yellow), Asia (5,464 km) 
Ob-Irtysh, Asia (5,410 km) 
Congo, Africa (4,370 km) 
Amur, Asia (4,416 km) 
Lena, Asia (4,400 km) 
Mackenzie-Peace, N. America (4,241 km) 
Mekong, Asia (4,184 km) 

MAJOR LAKES (by size) 
Caspian Sea, Asia-Europe (371,000 sq km) 
Superior, North America (82,100 sq km) 
Victoria, Africa (69,500 sq km) 
Huron, North America (59,600 sq km) 
Michigan, North America (57,800 sq km) 
Tanganyika, Africa (32,900 sq km) 
Baikal, Asia (31,500 sq km) 
Great Bear, North America (31,300 sq km) 
Aral Sea, Asia (30,700 sq km) 
Malawi, Africa (28,900 sq km)