The single variable that explains most of what you see is how thick the lava was. Runny lava spreads out and builds gentle slopes; thick lava traps gas, moves barely…
A quarry is a negative space that explains a positive one. The buildings, the walls, the roofs and the roads of an area all came from the ground somewhere in…
Every spring is an intersection between water moving underground and a surface that happens to be in the way. The rock decides where, and everything else follows. Here are fourteen.…
Coastlines are not eroded evenly. The sea attacks everything and removes softer material faster, which is why almost every coast is a sequence of projections and indentations rather than a…
Every gorge answers two questions: what removed the rock, and why did the sides not fall in afterwards. The second is frequently the more interesting. Here are seventeen answers.
1.…
The feature that makes a fjord a fjord is the sill at its entrance - a shallow threshold of rock and debris left where the glacier terminated. Water inside is…