There was some news over the weekend about steaming hills on the Pacific coast of California near Santa Barbara. Now, that might seem very surprising to many as there aren't any active volcanoes on the coast of California, especially near the Los Angeles basin - however, not all steam coming from the ground is related to magma.
All throughout the world, you can find hot springs and steam coming from heat transferred along fault zones - where rock has experienced brittle failure. These faults are excellent places for heat from within the crust to move towards the surface - and remember, even in non-tectonically active areas, the ground warms at almost 2-3C per 100 m, so it can get hot enough to boil water quite quickly (note that as the lithostatic pressure from rocks overhead goes up as you go down, the boiling point of water goes up as well, ...
