Region
United States
270
Pennsylvania
42
California
21
Wisconsin
19
Montana
17
Great Britain
16
Canada
15
China
13
Arizona
12
France
12
Oregon
12
Virginia
12
Europe
11
Germany
10
Alaska
9
Colorado
9
Australia
8
Florida
8
Nevada
8
New Mexico
8
New York (State)
8
Floridan Aquifer
7
Illinois
7
Developing countries
6
England
6
Mexico
6
Mohave County
6
North America
6
San Francisco Bay Area
6
Italy
5
Japan
5
Nevada National Security Site
5
Outer space
5
Texas
5
Washington (State)
5
West (U.S.)
5
États-Unis
5
Africa
4
Brazil
4
Dawson County
4
Indiana
4
Louisiana
4
Malheur County
4
Michigan
4
New Jersey
4
New York
4
Ohio
4
Philadelphia
4
Utah
4
Vermont
4
more ...