This image is shot at Hraunfossar, and is one of the images from last years POADS workshop in Iceland. The waterfall is kind of puzzling. The water just seems to emerge from the riverbank, which is lined with basalt rock; the water flows from a waterfall a bit further up the river and along the basalt rock through the looser material which covers the basalt and pours out of the riverbank here.
PhaseOne 645DF, IQ160, PhaseOne 150mm f/2.8 IF, ISO50 f/6.3 at 1/200s