Known for its extremely clear waters, Blue Lake or Rotomairewhenua in Māori is a little lake found in Nelson Lakes National Park. This is in the northern parts of New Zealand’s Southern Alps. The place is hallowed ground to local Māori, and has the purest natural fresh water on the planet. Rotomairewhenua is emptied by the west branch of the Sabine River, a body of water that is part of the Buller River system.
The Blue Lake is fed by a short higher segment of the Sabine, and in turn is fed underground via the landslide debris of the much bigger Lake Constance. Blue Lake can be described as boomerang contoured, traveling north then northwest, with each arm of the lake stretching some 700 feet. It has very cold waters ranging in temperature from 5 to 8 °C.
Rotomairewhenua possesses the clearest natural body of fresh water known to man. A study in 2011 found its visibility penetrated from 230 to 260 ft, clearer than the 207 ft recorded at Te Waikoropupu Springs, which was the previous record holder.
Laboratory measurements show distilled water has a visibility of around 260 ft, just to give a comparative idea of the purity of its waters. Scientists believe that the lake water’s purity is due to to its passage underground from Lake Constance. It is thought that it filters out practically all the particles found in the water. Visually its clarity shows the water as a natural blue-violet color.
The images that appear here are from Klaus Thymann of Project Pressure. Project Pressure was initiated by Klaus Thymann in 2008, which is now a not-for-profit organization “dedicated to creating the world’s first open source glacier archive.”
The main goal for the project is “to document the world’s changing glaciers, and to record first-hand the environmental impact of climate change. The organisation has official links with the World Glacier Monitoring Service (WGMS), the National Aeronautics and Space Administration (NASA), amongst others and is an contributor to the Global Terrestrial Network for Glaciers (GTN-G).”
View the amazing pictures of the Blue Lake or Rotomairewhenua here.