Green appears because the water that freezes is extremely rich in algae, hence the colour. Brown, yellow, and even black stripes are caused by sediments picked up along the way when the ice sheet was sliding downhill.
In March, Siberia's Lake Baikal is particularly amazing to photograph. The temperature, wind and sun cause the ice crust to crack and form beautiful turquoise blocks or ice hummocks on the lake’s surface. //So pretty EL//