The Crack of Silfra exists because of the North American and Eurasian hemispheres pulling apart. The massive earthquakes that take place approximately every 10 years lead to massive amounts of debris falling. Though it is a geological point of interest and on of the hottest scuba diving spots in the world, some parts are not safe to venture into. The point where divers enter, referred to as the "toilet" leads to the toilet-tunnel. This section alone has plenty of rocks and debris to navigate through, but will ultimately lead to the cathedral.
 |
| No, not that kind of cathedral |
The Silfra Cathedral is a long stretch of crystal-clear water measuring 20 meters deep and 100 meters across, with near perfect visibility and walls of lava rock.
 |
| See? Same thing as the cathedral you were thinking of. |
This leads into the Silfra Lagoon. The Lagoon is the most optimal diving location, with visibility up to 120 meters, the length of the final section.
I bring all this up so you might appreciate for a moment the geological wonder that is the Crack of Silfra and its various components. However, on a larger timeline, it is fairly obvious just how fragile the nature of this geological wonder is. With stability decreasing every 10 years due to earthquakes, in 10,000 or 1 million years, I predict that the Crack of Silfra will be no more. I estimate that in 10,000 years, there will be enough debris to essentially smooth out the entire crack, resulting in a widening of the Þingvallavatn Lake. Though the Crack of Silfra might be doomed to be forgotten in a theoretically small time on a larger scale, predictions about Iceland as a whole can still be speculated upon.
In one million years, I predict a larger impact of the tectonic plates pulling apart. Meaning, if Iceland is still above water - which is not even a certainty - I believe that it could be split into two separate entities, divided by a large lake, essentially mimicking how the Mediterranean Sea splits Europe and Africa, or at least into a massive canyon. As you can see in the image below, Iceland is being pulled apart almost right down the middle, via the example of the Mid-Atlantic Ridge:
On such a large scale as that of looking 100 million years into the future, there is concern of supervolcanos. These monsters would cause havoc in several ways, including massive amounts of lava exploding over large areas, incredible amounts of sulfur dioxide, chlorine, and fluorine being released, and a significant amount of ash that, in combination with wind patterns, be devastating to many ecosystems. Iceland has over 30 active volcanoes and almost acts as a breeding ground for them, so the eventual formation and eruption of a supervolcano is not outside of the realm of possibility.
That is, if a gigantic meteor doesn't hit the Earth and destroy everything first (which, according to Stephen A. Nelson, pretty likely to occur in 100 million years).
Nelson, Stephen A. "Meteorites, Impacts, and Mass Extinction". Tulane University. Retrieved 13 January 2011.
Smith, Cameron; Davies, Evan T. (2012).Emigrating Beyond Earth: Human Adaptation and Space Colonization. Springer. p. 258.
