+ The Great Glacier

The Great Glacier - O'Higgins

RETURN TO FREEDOM IN ITS PUREST FORM

 

In Deep Patagonia you will be able to travel to magnificent glaciers which are living works of art, picture postcard images that will remain within you for eve.

Everything is there for a profound experience: the journey, the adventure, intense sensations and that wild, primeval natural beauty that is capable of astonishing humanity! . After being there, nothing will ever be the same.

The experience, and the desire to re-live it one day, will remain in our subconscious. The strength of Deep Patagonia manifests itself in a spiritual relationship that depends on neither time nor space, but simply lives on in the emotion that reminds us that we returned for a brief moment to freedom in its purest state..

In Deep Patagonia you will be able to travel to magnificent glaciers which are living works of art, picture postcard images that will remain within you for ever.

The exploration toward the Great Glacier will be an unforgettable experience. You must sail across Glacier Lake until reaching the imposing “Great Glacier” (Glaciar O’Higgins, or Ventisquero Grande, as it is known to the local inhabitants), at the foot of the “Southern Patagonian Ice Field” plateau (Campo de Hielo Patagónico Sur), one of the largest and most dynamic glaciers in the Patagonia, Southern Hemisphere. It has 291 square milesof ice and stretches 24 milesin length from Lautaro Volcano to Glacier Lake (Lago O’Higgins). Its spectacular front wall has 3 miles wide and rises about 80 meters from the mirror of the lake.

 

The Glaciers

Glaciers belong to the last ice era on earth that occurred more than 10,000 years ago. At present times more than 17,400 Km2 of ice on top of the Patagonian waters are covered with ice; 80% of this area belongs to Chile and 20% to Argentinean lakes. The appearance of these enormous ice pieces at this latitude can be explained due to the rapid and rigorous Patagonia weather change. The west glaciers can reach the ocean; meanwhile, the east has the Patagonian lakes of O´Higgins, Viedma and Argentino.

¿What is a Glacier?

A glacier is a perennial mass of ice formed by snow accumulation, its shape or size does not make any difference. The necessary condition to gather the ice in the glacier is when the amount of snow exceeds ablation over many years. This climatic condition can be found at high altitudes such as in the highest mountains on earth.

Glacier or Snow Storm?

Both of these terms can be correct if you are referring to the ice-mass. The snow storm definition can be explained when this ice mass generate permanent ice storms due to constant local climatic pressure.

Ice Formation

The snow accumulation throughout the years is usually transformed into ice. The ice crystals found from the previous years, create bigger chunks of ice called firn. Time goes on and the firn is covered by new snow that gets compacted, thicker, and it forces the interior to lose air. Some years later white ice is formed. In Greenland and the Antarctic the process of superficial defrosting or melting can occur over hundreds of years. While the ice crystals continue growing due to more snow accumulation, air is almost completely expelled and the ice turns blue. Many times this blue ice is covered with new snow or firn, this is hard to observe; however, it can be found at the O´Higgins glacier.

GLACIER’S MOTION

How does a glacier move?

The glaciers rate of movement depends on the underlying slope and acts as a plastic flow. When it moves, some zones debilitate and transport layers of molecules that are abandoned. Its motion is related to two processes: 1. Internal flow: name is related to the crystal deformation. Surface at this stage is more fragile and cracks are formed. 2. Basal sliding: In this process, the glacier slides over the terrain on which it sits. The glacier´s foundation may have liquid water that allows the ice to move between rocks. This type of movement is dominant in temperate or warm-based glaciers.

Glacier´s Advance and backward motion

The glaciers' retreat "by direct radiation from the sun, by the influence of hot air, direct evaporation of ice and rain and dew. This whole process is called ablation and is expressed in the retreat of the glacier front or thinning of the ice mass. The advance of glaciers is due to higher amounts of rainfall over the feeding area, although other factors may influence such as modifying catchments rainfall.

Cracks and Seracs

These terms are explained as columns of ice formed by intersecting crevasses on a glacier. Tension in different areas of the plastic ice is not always absorbent; as a result a crack may appear at the surface. Due to heavy pressures the deeper side of the ice is compacted. Cracks may vary in length and width and become hazardous to climbers because fragile snow bridges may be formed and may not be visible from the surface. On the other hand, some of these bridges may be solid enough to support a person. When the glacier foundation has a deep decline, the ice movement can increase its speed in a short distance. This sudden speed change creates a series of fractures in the ice fall´s surface that creates a chaotic accumulation of ice bulks or seracs with an uneven equilibrium. Any weather alteration of air, rain, temperature change, or ice falls coming from above could collapse the ice walls. This ice falls together with the cracks on the ice surface can cause mortal accidents to glacier mountaineers.

Glacier Erosion

Different mechanisms are found at the erosion period of a glacier such as loosening up of material, wear out, and abrasion. The incorporated material found in ice may be transported long distances until the abrasion zone is reached. The substance that is in contact with ice and rocks starts wearing out and adapting shapes similar to bedrock. When deterioration occurs, clay like particles of rock produce what is call glacial flour. These unsorted sediments transported in the abrasion area are called glacial till. Glacial moraines are formed by the deposition of material from a glacier and are exposed after the glacier has retreated. Till is deposited at the terminal moraine, along the lateral and medial moraines and in the ground moraine of a glacier.

The Moraine

A moraine is any glacially formed accumulation of unconsolidated glacial debris (soil and rock) which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past ice age. This is a common and amazing event that has been of major importance to scientists since they track the journeys of past glacier. Also, these organic left overs can be studied using Carbon 14 database and chronological information of ancient glacier movements can be obtained. Moraines can also be classified according to their position as lateral or ground moraines. These two are a consequence of the union of the lateral moraines and its flow. Accumulation of unconsolidated glacial debris (soil and rock) flows in the glacier center following the direction it needs to go. Another important type of moraine for a glaciologist is the end or terminal moraine that is as self explained, ridges of unconsolidated debris deposited at the snout or end of the glacier.

The icebergs

An interesting phenomenon that occurs at glaciers is the formation of “icebergs”. An iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. Typically only one-ninth of the volume of an iceberg is above water while the rest is under water. When icebergs are separated from the glacier usually confined by wings, they move to the coast and navigation might get difficult.

Topographic Forms originated in the Glaciers

Glacial erosion has a powerful impact on the surface of our planet. This is visible at the Patagonian zone where it is demonstrated by pyramid-shape mountains, deep valleys with an “u” form, lakes and rocks. Sharp pointed edges emphasize the view and the moraines can also be observed on top of the glacier.

Why are Glaciers important

Glaciers play a very important role globally. Even though this water represents only 10% of our earth´s surface, glacier ice represents the largest reservoir of fresh water (by a 90%) on Earth. This is important data since drinkable water is getting limited due to water contamination. Also, glaciers create air and water flows that help to balance climatic conditions on our planet. Without this important natural phenomenon our air would be suffocating. Glaciers were also responsible, back in time, for transporting, excavating, and pulverizing different types of minerals. Years later particles were distributed around many parts of our globe due to violent storms that blew from the main ice mass of the Glacier to China, North America, Central Europe and Argentina, creating extremely fertile soil great for agriculture.

 

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