Topics
Climate
40
Climatology
31
Archaeological surveying
14
Antiquities
13
Hydrology
9
Ice on rivers, lakes, etc
9
Environmental aspects
8
Hydroelectric power plants
8
Ice mechanics
6
Dams
5
Geology
5
Temperature
5
Economic conditions
4
Measurement
4
Economic aspects
3
Freezes (Meteorology)
3
Historic sites
3
Ice
3
Social conditions
3
Stream measurements
3
Alaska Natives
2
Economic history
2
Excavations (Archaeology)
2
Indians of North America
2
Regional economics
2
Social aspects
2
Air quality
1
Animals
1
Archaeological geology
1
Bird surveys
1
Birds of prey
1
Cultural property
1
Data processing
1
Design and construction
1
Ecology
1
Economic surveys
1
Environmental conditions
1
Ethnology
1
Fishes
1
Geographic information systems
1
Geological surveys
1
Licenses
1
Meteorology
1
Methodology
1
Municipal services
1
Observations
1
Paleontological excavations
1
Particles
1
Peregrine falcon
1
Power utilization
1
more ...