Against Mount Cook, Lake Pukaki's milky-turquoise waves produce one of the most often photographed scenes in New Zealand. The unique hue of the lake results from glacial flour, very finely ground rock fragments from nearby glaciers. These suspended particles reflect sunlight to provide the distinctive blue color of the lake. Maintaining its natural beauty, the lake is part of a hydropower system that shows how human infrastructure could coexist with natural beauties. The glaciers of the Southern Alps ground underlying rock into particles finer than sand, which provides the glacial flour giving the lake its color. This ongoing process guarantees a constant supply of suspended particles, therefore preserving the lake's famous color all year long. Because of its location in the Mackenzie Basin, the lake experiences strong winds that produce standing waves that assist to maintain the glacial flour suspended. Studies have revealed that the unique color of the lake changes depending on seasonal glacier melt patterns and meteorological circumstances, therefore offering scientists markers of effects of climate change on glacial systems.
