Penitentes also known as nieves penitents are one of the wonderful natural phenomenon occurring in the world. They are snow formations, occurring naturally, at very high altitudes. The snow formations are in the shape of thin and tall blades of hard ice or snow rising upwards towards the sun. Penitentes are usually formed in clusters and can vary in height anywhere from six to ten feet high.
Penitentes form all over the ice covered regions in Dry Andes situated above 4,000 m. Penitentes are a common sight in the regions between Argentina and Chile. The first mention of the word Penitentes is found in Darwin’s writings in 1839. He mentions how on 22 March 1835 when he was traveling to the Argentian City, Mendoza, from Santiago de Chile,he witnessed the snowfields filled with Penitentes just near the Piuquenes Pass. The locals believed the Penitentes to be the result of the strong winds prevalent in the Andes Mountains.
The longest Andes mountain ranges, located at a height of 4000 meters, abound with forests of towering Penitentes. The Andes extends over a length of 7000km along the west of South America and include the Andean countries of Venezuela, Ecuador, Argentina, Peru, Chile, and Bolivia. The Penitentes when small resemble grasslands and when they occur in clusters of towering heights, they resemble white forests of ice. The snow formation is such that they seem to be an assembly of ice monks congregating to pray to the sun with folded hand and lost in devotion.
Scientists have done a lot of research on the formation of this natural phenomenon of ice towers. Liboutry is one of the scientists who has done much study in this area and has concluded that Penitentes are a result of differential ablation. (where snow gets evaporated).On high altitude glaciers due to the dry air, the sun rays do not necessarily melt the ice but instead can change the ice into water vapor directly through what is called the process of Sublimation. Some areas may sublimate more speedily than others which may result in random depressions on the smooth surface of the snow. Sunlight gets concentrated on these curved surfaces speeding up the process of sublimation in these areas resulting in the higher spikes of ice formations called the penitents.
Recently scientists have argued that the presence of carbon or any other impurities lead to some absorption of sunlight and the resultant occurrence of Penitentes. If this theory is to be believed, then the glaciers could be saved from the onslaught of global warming. There are counter arguments to this claim that if the Penitentes absorb more sunlight due to the presence of carbon, they may also result in the destruction of the icebergs. Studies are being pursued in this field to discover the effect of global warming on the formation of Penitentes.