Nicknamed watermelon snow by many climbers, the red patches in spring snow are actually one step in the lifecycle of green algae. Chlamydomonas nivalis has a red pigment in its cyst stage to protect it from harsh sunlight. Each year the cysts are buried under new snow. When the snow starts to melt in the spring, the cysts burst and release single cells with whip like tails. The cells must swim upwards through the melt water and reach sunlight where they photosynthesize and reproduce. Every spring huge colonies of these algae thrive in the ablation melt waters on Blue Glacier. Different species of algae are responsible for red, green, and orange tinting in snow. Yellow snow is from something else.
WATERMELON SNOW

MORAINES>

intro | terminology | accumulation | firn | blue | ablation | water | equilibrium | massbalance | movement | crevasse | structure | algae | moraine | debris | erosion
pdf version | glacier glossary | bibliography | about blue ice

Benjamin Drummond 2002