Reykjavík means smokey bay and the city got that name because, early settlers mistook the steam rising from the ground for fire. You’d have thought they’d change the name to steamy bay once they’d worked out what was going on, but smokey bay had already stuck. Nobody had seen anything like it.
Geysers are to be found all over Iceland, but few erupt as regularly as Stokkur which shoots boiling water into the air every few minutes. This is a place to be careful where you stand and where you tread, as the land is fragile in places and it’s possible to step through into the ultra-hot water below.
Water from rain and snow can take hundreds of years to soak through the earth into reservoirs formed where the land has been disrupted by earthquakes and other volcanic activity. The water is heated to around 240C, at which point it should well and truly be steam but steam takes up sixteen times as much space as water and there simply isn’t the room. Consequently, the pressure is enormous and, as you can see, explosive.