A volcanic eruption subject to glacial exposure at surface
A volcanic eruption subject to glacial exposure at surface
The state of reduced clarity of liquid, due to the concentration of suspended sedimentary or other particles
A large tunneling machine capable of drilling large tunnel and room sizes passages in solid rock
An opening and passage into a mine
A hard, brittle, metal. Symbol, W
A part of the arctic and subarctic region unsupportive of larger rooted plants and trees due to permafrost