Silfra - diving between tectonic plates
Thingvellir is by far the most important historical site in Iceland. In fact, by the year 930 the Althing was founded by the vikings - the oldest known parliament. Once a year these men came together to pass new bills or remember the old ones. Apart from many other important events that took place at this site, Iceland's independence was declared here as well in 1944.
The landscape is marked geographically by a huge depression between two rifts running northeast. As the two main continental tectonic plates are drifting here apart (2 cm per year), the rift valley is constantly sinking. Here in Thingvellir you can easily be witness of this impressive geological happening.
The result of this geological phenomenon is the lake Thingvallavatn - the largest natural lake in Iceland - and more interesting for divers are the countless fissures filled with cristal clear spring water. These underwater canyons, tunnels and caves are among the most impressive dive sites in the world due to their amazing underwater visibility and scenery.
The source of the springs are 1/3 glacier water that takes 10 years to re-emerge mixed with 2/3 of rain water. The filtration through the lava rocks produces pure icy water.
Silfra is one of those fissures that are filled with water, so clear that the visibility reaches 50 m and more, especially in the shallow water ponds with absolutely no suspended plankton - water like air.
The first part of the fissure is characterized by a deep cave that leads under the road. The following part is divided by several deep ponds that are connected by tunnels in between the lava rocks.
After all, Silfra in Thingvellir is a top world dive site on it's own as it may be unique. A divers dream... [JK]