Alex Mustard / A diver explores Silfra Canyon, a deep fault filled with fresh water in the rift valley between the Eurasian and American tectonic plates at Thingvellir National Park, Iceland. May 2011. In this phot...

Alex Mustard,Alex Mustard / Pair of divers floating in Silfra Canyon, a deep fault filled with fresh water in the rift valley between the Eurasian and American tectonic plates) at Thingvellir National Park, Iceland. May 2011. I...

Alex Mustard / The narrow Nes Canyon, a fault filled with fresh water in the rift valley between the Eurasian and American tectonic plates in northern Iceland. May 2011.

Alex Mustard,Alex Mustard / A view down Nikulasargj Canyon, deep fault filled with fresh water in the rift valley between the Eurasian and American tectonic plates at Thingvellir National Park, Iceland. May 2011. In this photo t...

Alex Mustard / Diver explores the cathedral at Silfra Canyon, deep fault filled with fresh water in the rift valley between the Eurasian and American tectonic plates, at Thingvellir National Park, Iceland. May 2011....

Alex Mustard / A diver explores Nikulasargj Canyona deep fault filled with fresh water in the rift valley between the Eurasian and American tectonic plates at Thingvellir National Park, Iceland. May 2011. In this ph...

Ashley Cooper / Capturing geothermal steam from boreholes to power the Svartsengi geothermal power station in Keflavik near Reykjavik in Iceland. September 2010. The power station produces electricity and supplies ho...

Ashley Cooper / Capturing geothermal steam from boreholes to power the Svartsengi geothermal power station in Keflavik near Reykjavik in Iceland. September 2010. The power station produces electricity and supplies ho...

Ashley Cooper / Hellisheidi geothermal power station in Hengill, Iceland. It also supplies hot water via a pipeline to Reykjavik for space heating for households and industry September 2010.

Ashley Cooper / Hellisheidi geothermal power station in Hengill, Iceland. It also supplies hot water via a pipeline to Reykjavik for space heating for households and industry September 2010.

Ashley Cooper / Krafla geothermal power station near Myvatn, Iceland, which produces electricity as well as supplying hot water to heat buildings in the surrounding area. September 2010.

Ashley Cooper / Fumaroles emitting steam in the geothermal area of Hverir near Myvatn, northern Iceland, September 2010.