Gullfoss is actually two separate waterfalls, the upper one has a drop of 11 metres and the lower one 21 metres. The rock of the river bed was formed during an interglacial period.
Water flows over Gullfoss at an average rate of 109 cubic metres per second. The heaviest floods have recorded a flow of 2000 cubic metres per second. During the summer the flow is 130 cubic metres per second, which would take only 3 seconds to fill this building. People were eager to exploit the power potential of Gullfoss and many plans for hydroelectric developments on the river Hvitá have been proposed.
The canyon below Gullfoss extends for some 2.5 kilometres and reaches a depth of 70 metres.
Geologists have suggested that it may have been formed in torrential floods caused by socalled jökulhlaup (glacial outbursts), occurring near the end of the last ice age.
The end of the last ice age in Iceland. The ocean extends far inland, a continuous glacial cap covers the entire highland area. The river, falling from the edge of the highland area, has not yet formed a canyon.
As the glacier retreats the land rises from the sea. Under the edges of the glacier large masses of meltwater collect, restrained for a time by the ice mass, and then surge forth.
During a jökulhlaup (glacial outbursts) the amount of water running seaward during a single 24-hour period can equal normal flow of up to five years, but the erosive force of such sudden deluges is many time greater.
In the yawning canyon, with grassy hollows along its upper edges, the great river winding between the gravel bars along the bottom appears a mere trickle. These are typical remains of a jökulhlaup (glacial outbursts).
Gullfoss is an example of a waterfall forming where the water has followed a fissure in the lava and carved a passageway through it.
Geologists have suggested that it may have been formed in torrential floods caused by socalled jökulhlaup (glacial outbursts), occurring near the end of the last ice age.
The end of the last ice age in Iceland. The ocean extends far inland, a continuous glacial cap covers the entire highland area. The river, falling from the edge of the highland area, has not yet formed a canyon.
As the glacier retreats the land rises from the sea. Under the edges of the glacier large masses of meltwater collect, restrained for a time by the ice mass, and then surge forth.
During a jökulhlaup (glacial outbursts) the amount of water running seaward during a single 24-hour period can equal normal flow of up to five years, but the erosive force of such sudden deluges is many time greater.
In the yawning canyon, with grassy hollows along its upper edges, the great river winding between the gravel bars along the bottom appears a mere trickle. These are typical remains of a jökulhlaup (glacial outbursts).
Gullfoss is an example of a waterfall forming where the water has followed a fissure in the lava and carved a passageway through it.