Dettifoss is 144 feet (44 m) high and 330 feet (100 m) wide. They are considered to be the most powerful waterfalls in Europe, with an estimated 110,000 gallons (500,000 liters) of water passing over the falls every second. To the south is Selfoss, another cataract which is 33 feet (10 m) high, and the 90-foot (27-m) high Hafragilsfoss.
Below Dettifoss is a deep canyon, the Jökulsárglifúfur, which was gouged out by a series of catastrophic floods, the last occurring about 2,500 years ago. In the 1970s plans to build a hydroelectric power station were abandoned and the area is now protected.
Height of Dettifoss: 144 ft (44 m)
Width of falls: 330 ft (100 m)
Water flow of falls: 110,000 gal (500,000 l) per second”