Spatial Coverage
- Queensland10
- Arizona9
- Korea9
- Nevada9
- Powder River Basin (Wyo. and Mont.)9
- Baltic Sea8
- Japan8
- Saint Lawrence River8
- Saint Lawrence Seaway8
- United States8
- Washington (State)8
- Inland Sea (Japan)7
- New Zealand7
- North Atlantic Ocean7
- Alberta6
- Arkansas6
- Atlantic Coast (Brazil)6
- Middle East6
- Ontario, Lake (N.Y. and Ont.)6
- Pennsylvania6
