The Andes Ranges are places where the typical formations of penitentes are visible; they are the longest mountain range in the world with its underwater ridges, with a length of 7000 km and a breadth of 500 km. It has an average height of about 4000 meters and spans along the western part of South America including Argentina, Chile, Peru, Bolivia, Ecuador and Venezuela.
Penitentes are amazing ice spikes formed naturally on plains at high altitudes areas especially on the Andes Ranges which are located more than 4000 meters above sea level. These ice pinnacles called penitentes attain varying heights from a few centimeters resembling grass lands to even 5 meters giving an impression of an ice forest. As their blades stand pointing towards the sun they resemble monks standing still as if in a deep prayer all facing one direction; towards the sun. When ice starts to melt in the early sunrays they slowly and steadily appear.
People of the Andes attributed this phenomenon to the speedy winds blow in that region which was only part of the process; wind had only limited role in shaping these beautiful statues. As per recent scientific observations the sunlight which falls on the ice heats it up moreover some of the light gets trapped in the ice they undergo numerous deflection within the ice blocks which lead to the unequal melting of the ice and those parts of the ice that has not melted remain giving birth to strange shaped statues known as the penitentes.
Penitentes were first described in the literature by Darwin in 1839. On March 22, 1835, he had to squeeze his way through snowfields covered in penitentes near the Piuquenes Pass, on the way from Santiago de Chile to the Argentinian city of Mendoza, and reported the local belief (continuing to the present day) that they were formed by the strong winds of the Andes.
Various scientists have done much research on this phenomenon Lliboutry is one among them. He has reached in this conclusion, these ice pinnacles are formed due to the differential ablation (ablation means removal of snow by melting or evaporation). The dew point (the temperature that is required for the dew to condense) is always below zero hence snow to sublimate (sublimation means solid changing directly to gas without undergoing the middle stage that is liquid). Sublimation requires higher energy input than melting.
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Penitentes ice formations at the southern end of the Chajnantor plain in Chile
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The initially smooth surfaces of the glaciers slowly and gradually develop depressions and the dry air takes away the ice in a process called sublimation. Due to the uneven ablation penitentes get formed and their surface geometry enables them to trap the incoming sunlight deflecting it within its walls. The hollow spaces become equal to black surface to absorb the light while the wind decrease air saturation increasing due point temperature and onset of melting.
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Penitentes Upper Rio Blanco Argentine (1.5-2m high)
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In the present scenario when the fossil fuels are burnt in quantities unheard of; in few years back and polluted air gnawing the ozone layer leaving gaping holes in the sky; attention of scientists turn to these phenomenon; seeking whether there is any answer for these problems in the phenomenon of penitentes formation. The researches are intended to slow down the melting of the icebergs which are fast receding and releasing the water that may engulf the low level lands and islands. If they succeed in the research on penitentes and find an answer it would be no small thing.
Interesting fact: Penitentes are named after the spiked hats of monks called Nazarenos from New Mexico.
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