The Northern Patagonian Ice Field, located in southern

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, is the smaller of two remnant parts in which the

Patagonian Ice Sheet upright=1.4, Map showing the extent of the Patagonian Ice Sheet in the Strait of Magellan area during the last glacial period. Selected modern settlements are shown with yellow dots. Sea level was much lower than shown here. The Patagonian Ice S ...

in the

Andes Mountains The Andes, Andes Mountains or Andean Mountains (; ) are the List of mountain ranges#Mountain ranges by length, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range i ...

of southern

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

can be divided. It is completely contained within the boundaries of

Laguna San Rafael National Park Laguna San Rafael National Park () is a park located on the Pacific coast of southern Chile. The park is named for the San Rafael Lagoon formed by the retreat of the San Rafael Glacier. Created in 1959, it covers an area of and includes the Nort ...

Description

The Northern Patagonian Ice Field is a vestige of the

, an extensive

ice sheet In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Las ...

that covered all of Chilean

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...

and the westernmost parts of Argentine Patagonia during the

Quaternary glaciation The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial and interglacial periods during the Quaternary period that began 2.58 Ma (million years ago) and is ongoing. Although geologists describe ...

s. Today, with its

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

s largely in retreat and only an area of , it is still the second largest continuous mass of ice outside of the

polar regions The polar regions, also called the frigid zones or polar zones, of Earth are the regions of the planet that surround its geographical poles (the North and South Poles), lying within the polar circles. These high latitudes are dominated by float ...

. Its survival depends on its elevation (), favorable terrain and a cool, moist, oceanic climate. The ice field has 28 exit glaciers, the largest two —

San Quintin San Quintín or San Quintin may refer to : Chile * San Quintín Glacier Mexico *San Quintín, Baja California ** San Quintín Volcanic Field Philippines *San Quintin, Abra *San Quintin, Pangasinan See also * Saint Quentin * Battle of St. Quentin ...

and San Rafael — nearly reach sea level to the west at the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

. Smaller exit glaciers, like San Valentín and Nef, feed numerous rivers and glacially carved lakes to the east.

Eric Shipton Eric Earle Shipton, CBE (1 August 1907 – 28 March 1977), was an English Himalayan mountaineer. Early years Shipton was born in Ceylon (now Sri Lanka) in 1907 where his father, a tea planter, died before he was three years old. When he was eigh ...

accompanied by Spaniard Miguel Gómez and Chileans Eduardo García and Cedomir Marangunic crossed the icecap from the San Raphael Glacier into Argentina in the summer of 1963–64. In 1972/73 a Joint Services expedition led by Captain CH Agnew of Lochnaw yr, now

Sir Crispin Agnew of Lochnaw Sir Crispin Hamlyn Agnew of Lochnaw, 11th Baronet, (born 13 May 1944) is a Scottish advocate, herald and former explorer. He is the chief of the ancient Agnew family, and the eleventh holder of the Agnew baronetcy, created in 1629. Agnew is th ...

, spent 5 months carrying out scientific research on and around the ice cap, including on the Benito Glacier, and three members of the expedition carried out a north-to-south crossing from the foot of

Monte San Valentín Monte San Valentin, also known as Monte San Clemente, is the highest mountain in Chilean Patagonia and the highest mountain south of 37°S outside Antarctica. It stands at the north end of the North Patagonian Icefield. Monte San Valentin ca ...

down to the snout of the Steffen Glacier. Martin Session, the glaciologist on the 1972/3 expedition returned to the Benito Glacier with others in 2007 and 2011 to continue his research. The Northern Patagonian Ice Field lies in fault-bounded

crustal block Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by tectonic and localized stresses in Earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by relat ...

that has been uplifted. To the west lies the Liquiñe-Ofqui Fault Zone, to the north the Exploradores Fault Zone and to the east the Cachet Fault. To the south there is possibly a zone of extensional faults around

Tortel Fjord Tortel Fjord ( es, Fiordo de Tortel) is an inlet of the Pacific Ocean in Chile's Aysén Region. The village of Caleta Tortel is located at the head of fjord In physical geography, a fjord or fiord () is a long, narrow inlet with steep sides or ...

References

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External links

Northern Patagonian Ice Field, Earth
{{Authority control Glaciers of Aysén Region Ice fields of South America