Water, Sewage & Effluent September October 2018 | Page 15

Water Sewage & Effluent September/October 2018
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technology
S
ilfra in Iceland is considered the
clearest body of water in the world.
Originating from a glacier and
flowing between two tectonic plates,
Silfra lets you be in two places at the
same time: North America and Europe,
with water so pristine that visibility can
reach 100m, with depths of up to 63m
and temperatures of 2°C.
Located in a section of the Earth’s
crust known as the Mid-Atlantic Ridge,
the 15  000km canyon separates the
Eurasian and North American tectonic
plates. While most of it is underground,
except for at the islands of the Azores
and in Iceland, this geological border,
accessible only underwater, is reached
via the second-biggest lake in Iceland,
the Þingvallavatn, in Þingvellir National
Park, 60km from Reykjavik.
This park is the only place in the
country that has been declared a
UNESCO World Heritage Site.
Every particle of H 2 O that reaches this
place has undergone a journey that took
30–100 years, from the nearest glacier,
Langjökull. Just 50km north of Þingvellir,
is the second-biggest glacier in Iceland.
As it thawed, it used to feed the lake, via
a river. But, several thousand years ago,
Skjaldbreiður volcano erupted and the
river was buried. When the ice melts, it
continues to flow along the same bed,
which is now covered with highly porous
volcanic rock. During its journey, the
water is filtered and cleaned. Combined
with the icy temperature, it becomes the
clearest water on the planet.
Source: www.dive.is/dive-sites/silfra