For inhabitants subpolar and midlatitudes snow – the phenomenon habitual. It seems that there is nothing surprising in it and cannot be, but even snow sometimes gives very interesting surprises. An indelible impression is made on people by color snow.
The type of color snow is capable to shock even such brave people as sailors. At the beginning of the 19th century the crew members of the sailing vessel passing near coast of Greenland were struck with a show of red snow. The first "bloody snow" on the narrow site between rocks was noticed by the log sailor. Sailors were captured by superstitious fear, many said that they "that's a bad sign" and demanded to turn back. Having hardly suppressed panic among crew members, the captain ordered to several sailors to go to the coast on the boat. As it became clear, snow was the most usual, but it was covered by the thin red film having nothing in common with blood.
Such phenomenon can be observed not only in Greenland, but also in the mountains of the Caucasus and also in Antarctica. Subsequently scientists established that responsible for "bloody snow" is the hlamidomonada snow – a microscopic alga of pinkish-red color. This microorganism is not afraid of cold therefore well breeds on a snow surface. Depending on quantity of individuals in colonies of seaweed, color of snow can vary from gentle-pink to blood-red. Existence of microscopic seaweed is capable to change not only color, but also other properties of snow. For example, in 2006 the residents of the State of Colorado (USA) tasted such snow, and it turned out that he reminds watermelon.
Color snow extremely seldom causes superstitious horror in modern people. There is other question more often – whether there is no speech about environmental disaster whether there is no health hazard. Residents of the Tyumen, Tomsk and Omsk regions on January 21, 2007 when in these regions the unusual snow dropped out asked such questions. Its color varied from light yellow to orange. Experts of the Ministry of Emergency Situations, having carried out the laboratory analysis of samples of snow, calmed citizens: snow did not contain any hazardous substances. At it there was only clay and sand dust which is kicked up in air during a sandstorm in the territory of Northern Kazakhstan and brought by wind to Western Siberia.
The dust transferred by wind – the most frequent reason of loss of color snow. Depending on nature of the soil which smallest particles were lifted in air the snow can be yellow, reddish or brown. In some cases unusual color of snow is connected with industrial emissions the atmosphere – such is there was a reason of the black snow which dropped out in 1969 in Sweden. Still there is a secret a reason of loss of green snow in California in 1955. Snow was poisonous – it caused the itching rash on skin, and those who took this snow in a mouth, soon died. As the most probable cause call nuclear weapons tests.