Lake Haiyaha, nestled within Rocky Mountain National Park in Colorado, captivates visitors with its striking blue hue. This alpine lake, situated over 10,000 feet above sea level, recently transformed from a clear appearance to a milky, vibrant turquoise or even green. Its distinct coloration draws curiosity about the natural processes that contribute to its unique visual appeal. Understanding the science behind this phenomenon reveals an interplay of light, water, and geology that shapes the lake’s appearance.
The Science Behind Water’s Color
Water appears blue due to how it interacts with sunlight. When light penetrates water, water molecules absorb longer wavelengths, such as red, orange, and yellow light. This absorption leaves shorter wavelengths, like blue and violet, to be scattered and reflected. The human eye is more sensitive to blue light, which is why large, deep bodies of clear water exhibit a blue tint. While the reflection of the sky can play a minor role, the intrinsic absorption and scattering properties of water are the primary reasons for its blue appearance.
Lake Haiyaha’s Distinct Environment
Lake Haiyaha is a glacial lake, formed by glaciers. Its primary water source is snowmelt and runoff from surrounding glaciers, contributing to its consistently cold temperatures. The lake is surrounded by rugged granite boulders and towering peaks, characteristic of the high-alpine environment in Rocky Mountain National Park. The indigenous name “Haiyaha” translates to “rock” or “lake of many rocks,” reflecting the prominent geological features. This geological context, particularly within Chaos Canyon, provides the raw materials for the lake’s distinctive appearance.
The Impact of Glacial Rock Flour
The intense blue and turquoise color of Lake Haiyaha is largely attributed to the presence of glacial rock flour. Glacial rock flour consists of extremely fine, silt-sized rock particles, created when glaciers grind against bedrock as they move. A significant landslide in Chaos Canyon in 2022 introduced a substantial amount of this finely ground material into Lake Haiyaha. These minute particles remain suspended in the water rather than settling quickly, giving the lake a cloudy, milky, or opaque appearance, sometimes referred to as “glacial milk.” When sunlight enters the water, these suspended rock flour particles scatter the blue and green wavelengths of light much more effectively than the water itself, and this amplification intensifies the lake’s coloration, making it appear a vibrant turquoise or milky green, especially prominent during warmer months when glacial meltwater inflow is higher.