The Silfra fissure in Iceland is the only place on the planet where you can freely swim between the continents of North America and Eurasia.
Located in Iceland’s Thingvellir (Þingvellir) National Park, the Silfra fissure is a gap that formed between the North American and Eurasian plates at a different tectonic boundary. Simply put, it’s the only place in the world where you can swim directly between the North American and European continents.
The Silfra fissure opened in 1789, due to the movement of the North American and Eurasian plates, running all the way through Iceland. The two plates are moving apart at a rate of about 2 cm (0.79 in) per year. This stress is relieved by periodic large earthquakes over a period of about ten years, causing cracks and fissures to form in the Þingvellir valley, with Silfra being one of the largest and deepest of them.
This giant fissure is filled with the clearest water in the world – so clean and pure, in fact, that it is drinkable and you can see more than 100 metres below the surface. The reason for this exceptional purity is the centuries-long filtration process – that’s how long it takes for the water to reach Silfra through the canyons that emerge from the Langjökull glacier.
However, there is one downside: the water here is extremely cold – around 35 to 39 degrees F year-round, to be exact.
Because of its unique location, the water is often a jewel-like blue and green. What’s more, with such low temperatures, you can even see rainbows when the sun’s rays refract through the water in good weather.
The fissure is so easily visible because the meltwater from Iceland’s glaciers is incredibly clear. Silfra is fed by groundwater from Iceland’s second-largest glacier, Langjökull, located about 50 km from Lake Thingvallavatn.
A group of American professional divers have measured the deepest point at Silfra, 63 meters. However, many people do not dare to risk their lives to dive that deep into this narrow canyon. Because this place is one of the most geologically active places in the world. Every year, earthquakes and volcanic activities cause tectonic plates to move apart by more than 2cm. However, this place attracts thousands of tourists and sea lovers from all over the world to experience the feeling of diving between two continents.
The word “silfra” means “silver” in Icelandic, referring to the frozen water. But beneath the surface, the water is bright blue and green, the deep cobalt of the crystal clear water contrasting with the neon green of the seaweed that clings to the rocks. Often called “troll hair,” the algae often takes on the appearance of spaghetti noodles.
