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124-546: The Beagle Channel, the Straits of Magellan to the north, and the open-ocean Drake Passage to the south are the three navigable passages around South America between the Pacific and Atlantic Oceans . Most commercial shipping uses the open-ocean Drake Passage. The Beagle Channel is about 240 kilometres (130 nmi; 150 mi) long and 5 kilometres (3 nmi; 3 mi) wide at its narrowest point. It extends from Nueva Island in

248-424: A cirque landform (alternatively known as a corrie or as a cwm ) – a typically armchair-shaped geological feature (such as a depression between mountains enclosed by arêtes ) – which collects and compresses through gravity the snow that falls into it. This snow accumulates and the weight of the snow falling above compacts it, forming névé (granular snow). Further crushing of the individual snowflakes and squeezing

372-846: A Chilean pilot between the Strait of Magellan and Ushuaia through the Magdalena Channel and the Cockburn Channel to the Pacific Ocean, then by the Ballenero Channel, the O'Brien Channel and the northwest branch of the Beagle Channel. The Beagle Channel is between islands covering a much larger area; to the north lies Argentine-Chilean Isla Grande de Tierra del Fuego , to the south Hoste , Navarino , and Picton and Nueva , which were claimed by Argentina until 1984. The latter two lie at

496-524: A Spanish expedition commanded by brothers Bartolomé and Gonzalo Nodal verified this discovery making in the way also the first circumnavigation of Tierra del Fuego. After this there would be 150 years before the next ship from Spain would traverse the strait. By 1620, one hundred years after European discovery, at least 55 ships had traversed the strait including 23 Spanish, 17 English and 15 Dutch. John Narborough 's 1670 explorations in Patagonia caused

620-431: A Voyage (1699). In the 18th century further explorations were done by English explorers John Byron and James Cook . The French sent Louis Antoine de Bougainville and Jules Dumont d'Urville . By 1770 the focus of a potential conflict between Spain and Britain had shifted from the strait to Falkland Islands . From 1826 to 1830, the strait was explored and thoroughly charted by Phillip Parker King , who commanded

744-560: A change, from the western archipelagoes to the strait, meant that any English settlement could be approached by Spain by land from the north, which was not the case for the islands in western Patagonia. In February 1696, the first French expedition under the command of M. de Gennes reached the Strait of Magellan. The expedition is described by the French explorer, engineer, and hydrographer François Froger  [ fr ] in his A Relation of

868-511: A glacier is usually assessed by determining the glacier mass balance or observing terminus behavior. Healthy glaciers have large accumulation zones, more than 60% of their area is snow-covered at the end of the melt season, and they have a terminus with a vigorous flow. Following the Little Ice Age 's end around 1850, glaciers around the Earth have retreated substantially . A slight cooling led to

992-595: A glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water. On Earth, 99% of glacial ice is contained within vast ice sheets (also known as "continental glaciers") in the polar regions , but glaciers may be found in mountain ranges on every continent other than the Australian mainland, including Oceania's high-latitude oceanic island countries such as New Zealand . Between latitudes 35°N and 35°S, glaciers occur only in

1116-411: A glacier via moulins . Streams within or beneath a glacier flow in englacial or sub-glacial tunnels. These tunnels sometimes reemerge at the glacier's surface. Most of the important processes controlling glacial motion occur in the ice-bed contact—even though it is only a few meters thick. The bed's temperature, roughness and softness define basal shear stress, which in turn defines whether movement of

1240-408: A kilometer per year. Eventually, the ice will be surging fast enough that it begins to thin, as accumulation cannot keep up with the transport. This thinning will increase the conductive heat loss, slowing the glacier and causing freezing. This freezing will slow the glacier further, often until it is stationary, whence the cycle can begin again. The flow of water under the glacial surface can have

1364-404: A large effect on the motion of the glacier itself. Subglacial lakes contain significant amounts of water, which can move fast: cubic kilometers can be transported between lakes over the course of a couple of years. This motion is thought to occur in two main modes: pipe flow involves liquid water moving through pipe-like conduits, like a sub-glacial river; sheet flow involves motion of water in

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1488-460: A lower heat conductance, meaning that the basal temperature is also likely to be higher. Bed temperature tends to vary in a cyclic fashion. A cool bed has a high strength, reducing the speed of the glacier. This increases the rate of accumulation, since newly fallen snow is not transported away. Consequently, the glacier thickens, with three consequences: firstly, the bed is better insulated, allowing greater retention of geothermal heat. Secondly,

1612-456: A primary refueling port that provided coal for steamships in transit. The Strait's curving channel, with widths varying between 1.9 and 22 miles (3 to 35 km), experiences unpredictable winds and tidal currents, leading sailing ships to prefer the Drake Passage, where they had more room to maneuver. ) in 1900, Joshua Slocum was the first documented person to have single-handedly sailed

1736-557: A sanctuary for humpback whales , is located in this area. This part of the strait lies on the elongated Magallanes-Fagnano Fault , which marks a plate boundary between the South American Plate and the Scotia Plate . This fault continues southward under Almirantazgo Fjord and then below Fagnano Lake . Possibly, new tourism industries could be established in the eastern part of the strait for watching southern right whales , as

1860-484: A thin layer. A switch between the two flow conditions may be associated with surging behavior. Indeed, the loss of sub-glacial water supply has been linked with the shut-down of ice movement in the Kamb ice stream. The subglacial motion of water is expressed in the surface topography of ice sheets, which slump down into vacated subglacial lakes. The speed of glacial displacement is partly determined by friction . Friction makes

1984-570: A total of 16–17 men perished in it. While by 1676 rumours about English bases in Western Patagonia had been dispelled, that year new rumours appeared claiming that England was preparing an expedition to settle the Straits of Magellan. The focus of Spanish attention to repel tentative English settlements shifted from the Pacific coast of Patagonia to the Straits of Magellan and Tierra del Fuego . Such

2108-410: A tremendous impact as the iceberg strikes the water. Tidewater glaciers undergo centuries-long cycles of advance and retreat that are much less affected by climate change than other glaciers. Thermally, a temperate glacier is at a melting point throughout the year, from its surface to its base. The ice of a polar glacier is always below the freezing threshold from the surface to its base, although

2232-617: A witch who was said to have "retained the waters and the foods". The channel was named after the ship HMS Beagle during its first hydrographic survey of the coasts of the southern part of South America which lasted from 1826 to 1830. During that expedition, under the overall command of Commander Phillip Parker King , the Beagle 's captain Pringle Stokes committed suicide and was replaced by captain Robert FitzRoy . The ship continued

2356-468: Is a persistent body of dense ice that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries . It acquires distinguishing features, such as crevasses and seracs , as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques , moraines , or fjords . Although

2480-456: Is above or at freezing at the interface and is able to slide at this contact. This contrast is thought to a large extent to govern the ability of a glacier to effectively erode its bed , as sliding ice promotes plucking at rock from the surface below. Glaciers which are partly cold-based and partly warm-based are known as polythermal . Glaciers form where the accumulation of snow and ice exceeds ablation . A glacier usually originates from

2604-407: Is affected by factors such as slope, ice thickness, snowfall, longitudinal confinement, basal temperature, meltwater production, and bed hardness. A few glaciers have periods of very rapid advancement called surges . These glaciers exhibit normal movement until suddenly they accelerate, then return to their previous movement state. These surges may be caused by the failure of the underlying bedrock,

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2728-411: Is because these peaks are located near or in the hyperarid Atacama Desert . Glaciers erode terrain through two principal processes: plucking and abrasion . As glaciers flow over bedrock, they soften and lift blocks of rock into the ice. This process, called plucking, is caused by subglacial water that penetrates fractures in the bedrock and subsequently freezes and expands. This expansion causes

2852-406: Is by basal sliding, where meltwater forms between the ice and the bed itself. Whether a bed is hard or soft depends on the porosity and pore pressure; higher porosity decreases the sediment strength (thus increases the shear stress τ B ). Porosity may vary through a range of methods. Bed softness may vary in space or time, and changes dramatically from glacier to glacier. An important factor

2976-434: Is called glaciology . Glaciers are important components of the global cryosphere . Glaciers are categorized by their morphology, thermal characteristics, and behavior. Alpine glaciers form on the crests and slopes of mountains. A glacier that fills a valley is called a valley glacier , or alternatively, an alpine glacier or mountain glacier . A large body of glacial ice astride a mountain, mountain range, or volcano

3100-416: Is called rock flour and is made up of rock grains between 0.002 and 0.00625 mm in size. Abrasion leads to steeper valley walls and mountain slopes in alpine settings, which can cause avalanches and rock slides, which add even more material to the glacier. Glacial abrasion is commonly characterized by glacial striations . Glaciers produce these when they contain large boulders that carve long scratches in

3224-597: Is connected with other sheltered waterways via the Smyth Channel . This area is similar to the Inside Passage of Alaska . South of Cape Froward, the principal shipping route follows the Magdalena Channel . The climate is generally foggy and cold, and the course is convoluted with several narrow passages. It is several hundred miles shorter than the Drake Passage , but sailing ships , particularly clipper ships , prefer

3348-499: Is enormous tidal energy potential in the strait. The strait is prone to Williwaws , "a sudden violent, cold, katabatic gust of wind descending from a mountainous coast of high latitudes to the sea". The place names of the area around the strait come from a variety of languages. Many are from Spanish and English, and several are from the Ona language , adapted to Spanish phonology and spelling. Examples include Timaukel (a hamlet at

3472-628: Is higher, and the mountains above 5,000 m (16,400 ft) usually have permanent snow. Even at high latitudes, glacier formation is not inevitable. Areas of the Arctic , such as Banks Island , and the McMurdo Dry Valleys in Antarctica are considered polar deserts where glaciers cannot form because they receive little snowfall despite the bitter cold. Cold air, unlike warm air, is unable to transport much water vapor. Even during glacial periods of

3596-486: Is named, became the first Europeans to discover it. Magellan's original name for the strait was Estrecho de Todos los Santos ("Strait of All Saints"). The King of Spain, Emperor Charles V , who sponsored the Magellan-Elcano expedition, changed the name to the Strait of Magellan in honor of Magellan. The route is difficult to navigate due to frequent narrows and unpredictable winds and currents. Maritime piloting

3720-649: Is now compulsory. The strait is shorter and more sheltered than the Drake Passage , the often stormy open sea route around Cape Horn , which is beset by frequent gale -force winds and icebergs . Along with the Beagle Channel , the strait was one of the few sea routes between the Atlantic and Pacific before the construction of the Panama Canal . Land adjacent to the Strait of Magellan has been inhabited by indigenous Americans for at least 13,000 years. Upon their arrival to

3844-897: Is termed an ice cap or ice field . Ice caps have an area less than 50,000 km (19,000 sq mi) by definition. Glacial bodies larger than 50,000 km (19,000 sq mi) are called ice sheets or continental glaciers . Several kilometers deep, they obscure the underlying topography. Only nunataks protrude from their surfaces. The only extant ice sheets are the two that cover most of Antarctica and Greenland. They contain vast quantities of freshwater, enough that if both melted, global sea levels would rise by over 70 m (230 ft). Portions of an ice sheet or cap that extend into water are called ice shelves ; they tend to be thin with limited slopes and reduced velocities. Narrow, fast-moving sections of an ice sheet are called ice streams . In Antarctica, many ice streams drain into large ice shelves . Some drain directly into

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3968-413: Is the region where there is a net loss in glacier mass. The upper part of a glacier, where accumulation exceeds ablation, is called the accumulation zone . The equilibrium line separates the ablation zone and the accumulation zone; it is the contour where the amount of new snow gained by accumulation is equal to the amount of ice lost through ablation. In general, the accumulation zone accounts for 60–70% of

4092-402: Is the underlying geology; glacial speeds tend to differ more when they change bedrock than when the gradient changes. Further, bed roughness can also act to slow glacial motion. The roughness of the bed is a measure of how many boulders and obstacles protrude into the overlying ice. Ice flows around these obstacles by melting under the high pressure on their stoss side ; the resultant meltwater

4216-552: Is then forced into the cavity arising in their lee side , where it re-freezes. As well as affecting the sediment stress, fluid pressure (p w ) can affect the friction between the glacier and the bed. High fluid pressure provides a buoyancy force upwards on the glacier, reducing the friction at its base. The fluid pressure is compared to the ice overburden pressure, p i , given by ρgh. Under fast-flowing ice streams, these two pressures will be approximately equal, with an effective pressure (p i – p w ) of 30 kPa; i.e. all of

4340-952: The Andes , the Himalayas , the Rocky Mountains , the Caucasus , Scandinavian Mountains , and the Alps . Snezhnika glacier in Pirin Mountain, Bulgaria with a latitude of 41°46′09″ N is the southernmost glacial mass in Europe. Mainland Australia currently contains no glaciers, although a small glacier on Mount Kosciuszko was present in the last glacial period . In New Guinea, small, rapidly diminishing, glaciers are located on Puncak Jaya . Africa has glaciers on Mount Kilimanjaro in Tanzania, on Mount Kenya , and in

4464-511: The Council of the Indies the possibility of establishing contacts between Chile and Seville through the strait. García Jofré de Loaiza was the second captain to navigate the strait and the first to discover that Tierra del Fuego was an island. Valdivia then dispatched Francisco de Ulloa to survey and explore the strait, facilitating navigation from Spain to Chile. In October 1553, Ulloa sailed from

4588-636: The Faroe and Crozet Islands were completely glaciated. The permanent snow cover necessary for glacier formation is affected by factors such as the degree of slope on the land, amount of snowfall and the winds. Glaciers can be found in all latitudes except from 20° to 27° north and south of the equator where the presence of the descending limb of the Hadley circulation lowers precipitation so much that with high insolation snow lines reach above 6,500 m (21,330 ft). Between 19˚N and 19˚S, however, precipitation

4712-750: The Himalayas , Andes , and a few high mountains in East Africa, Mexico, New Guinea and on Zard-Kuh in Iran. With more than 7,000 known glaciers, Pakistan has more glacial ice than any other country outside the polar regions. Glaciers cover about 10% of Earth's land surface. Continental glaciers cover nearly 13 million km (5 million sq mi) or about 98% of Antarctica 's 13.2 million km (5.1 million sq mi), with an average thickness of ice 2,100 m (7,000 ft). Greenland and Patagonia also have huge expanses of continental glaciers. The volume of glaciers, not including

4836-551: The Quaternary , Manchuria , lowland Siberia , and central and northern Alaska , though extraordinarily cold, had such light snowfall that glaciers could not form. In addition to the dry, unglaciated polar regions, some mountains and volcanoes in Bolivia, Chile and Argentina are high (4,500 to 6,900 m or 14,800 to 22,600 ft) and cold, but the relative lack of precipitation prevents snow from accumulating into glaciers. This

4960-521: The Rwenzori Mountains . Oceanic islands with glaciers include Iceland, several of the islands off the coast of Norway including Svalbard and Jan Mayen to the far north, New Zealand and the subantarctic islands of Marion , Heard , Grande Terre (Kerguelen) and Bouvet . During glacial periods of the Quaternary, Taiwan , Hawaii on Mauna Kea and Tenerife also had large alpine glaciers, while

5084-507: The Spice Islands . His ships became the first to navigate the strait in 1520. The five ships included La Trinidad (110 tons, 55 crew members), under the command of Magellan; La San Antonio (120 tons, 60 crew members) under the command of Juan de Cartagena ; La Concepción (90 tons, 45 crew members) under the command of Gaspar de Quesada ( Juan Sebastián Elcano served as boatswain); La Victoria (85 tons, 42 crew members) under

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5208-582: The Treaty of Peace and Friendship of 1984 between Chile and Argentina the conflicts between two countries were settled and Argentina ratified the strait as Chilean. In 1840, the Pacific Steam Navigation Company became the first to use steamships for commercial traffic in the strait. Until the Panama Canal opened in 1914, the Strait of Magellan was the main route for steamships traveling from

5332-530: The 1530s Charles V divided South America and whatever was to be south of it into a series of grants to different conquistadors . The strait of Magellan and the area south of it went to Pedro Sánchez de la Hoz . In 1530 and 1531 the Fuggers held rights to trade through the strait of Magellan. While European trade with Asia through this route was thought to be possible, the Fuggers never developed this route. Andrés de Urdaneta who had first hand experience of

5456-448: The 1990s and 2000s. In a study using data from January 1993 through October 2005, more events were detected every year since 2002, and twice as many events were recorded in 2005 as there were in any other year. Ogives or Forbes bands are alternating wave crests and valleys that appear as dark and light bands of ice on glacier surfaces. They are linked to seasonal motion of glaciers; the width of one dark and one light band generally equals

5580-481: The Atlantic Ocean to the Pacific. It was often considered safer than the Drake Passage separating Cape Horn from Antarctica , as the Drake Passage is notorious for turbulent and unpredictable weather, and is frequented by icebergs and sea ice . Ships in the strait, protected by Tierra del Fuego to the south and the coast of continental South America to the north, crossed with relative ease, and Punta Arenas became

5704-427: The Beagle Channel, where he created paintings on board a sailing yacht. Beagle Channel is a prominent area to watch rare, endemic dolphins. Wildlife seen in the channel include: Mammals: Birds: Straits of Magellan The Strait of Magellan ( Spanish : Estrecho de Magallanes ), also called the Straits of Magellan , is a navigable sea route in southern Chile separating mainland South America to

5828-634: The British survey vessel HMS Adventure . In consort with HMS Beagle , King surveyed the complex coasts around the strait. A report on the survey was presented at two meetings of the Geographical Society of London in 1831. In connection to these explorations Robert FitzRoy came to suggest the establishment of a British base in strait to aid travel between the British Isles and Australia . The 1837 French expedition of Dumont D'Urville surveyed

5952-449: The King of Spain's ownership of the territory. Viceroy of Peru Baltasar de la Cueva issued orders to the governments of Chile , Chiloé and Río de la Plata to inquire about the men who disappeared at Evangelistas Islets. However no information about their fate came forth and it is presumed that the boat wrecked in the same storm that forced the remaining party to leave the area. Overall

6076-553: The Lords of the Admiralty to ask Mayne to collect several boatloads of fossils of extinct quadruped species. Admiral Sulivan had previously discovered an astonishingly rich accumulation of fossil bones not far from the strait. These remains apparently belonged to a more ancient period than collections made by Darwin on HMS Beagle and other naturalists, and therefore were of great scientific interest. Many of these fossils were collected with

6200-559: The O'Brien and Ballenero channels. The biggest settlement on the channel is Ushuaia in Argentina followed by Puerto Williams in Chile. These are amongst the southernmost settlements in the world. Although it is navigable by large ships, there are safer waters to the south ( Drake Passage ) and to the north ( Strait of Magellan ). Under the Treaty of Peace and Friendship of 1984 between Chile and Argentina , ships of other nations navigate with

6324-448: The Spanish collected intelligence from all over Patagonia. In 1599 it took five ships under Simon de Cordes and his pilot William Adams four months to traverse the strait; Sebalt de Weert returned before reaching the end. In 1616, Dutch travelers, including Willem Schouten and Jacob Le Maire , discovered Cape Horn and recognized the southern end of Tierra del Fuego. Years later,

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6448-492: The Spanish encountered difficulties, having to abandon their initial economic model based on gold mining and "hispanic-mediterranean" agriculture. In 1578 English navigator Francis Drake crossed the strait, creating fear on the Pacific coast that an attack was imminent. In order to seal the passage, the Viceroy of Peru, Francisco de Toledo , sent a squadron with two ships under Pedro Sarmiento de Gamboa . They carefully explored

6572-509: The Spanish southward in Chile halted after the conquest of the Chiloé Archipelago in 1567. The Spanish are thought to have lacked incentives for further conquests south. The indigenous populations were sparse and did not engage in the sedentary agricultural life of the Spanish. The harsh climate in the fjords and channels of Patagonia may also have deterred further expansion. Even in Chiloé

6696-424: The Spanish to launch various maritime expeditions to western Patagonia from 1674 to 1676. In the last and largest one , Pascual de Iriate led a party to Evangelistas Islets at the western entrance to the strait. At Evangelistas sixteen men of the party disappeared on February 17 including the son of Pascual de Iriarte. The ill-fated men had attempted to reach one of the islets to install a metal plaque indicating

6820-412: The advance of many alpine glaciers between 1950 and 1985, but since 1985 glacier retreat and mass loss has become larger and increasingly ubiquitous. Glaciers move downhill by the force of gravity and the internal deformation of ice. At the molecular level, ice consists of stacked layers of molecules with relatively weak bonds between layers. When the amount of strain (deformation) is proportional to

6944-531: The aid of hydrographer Richards R. N. and deposited in the British Museum . The Admiralty compiled advice to mariners of the strait in 1871. Chile took possession of the Strait of Magellan on May 23, 1843. President Manuel Bulnes ordered this expedition after consulting the Chilean libertador Bernardo O'Higgins , who feared an occupation by Great Britain or France. The first Chilean settlement, Fuerte Bulnes ,

7068-520: The air from the snow turns it into "glacial ice". This glacial ice will fill the cirque until it "overflows" through a geological weakness or vacancy, such as a gap between two mountains. When the mass of snow and ice reaches sufficient thickness, it begins to move by a combination of surface slope, gravity, and pressure. On steeper slopes, this can occur with as little as 15 m (49 ft) of snow-ice. In temperate glaciers, snow repeatedly freezes and thaws, changing into granular ice called firn . Under

7192-430: The amount of melting at surface of the glacier, the faster the ice will flow. Basal sliding is dominant in temperate or warm-based glaciers. The presence of basal meltwater depends on both bed temperature and other factors. For instance, the melting point of water decreases under pressure, meaning that water melts at a lower temperature under thicker glaciers. This acts as a "double whammy", because thicker glaciers have

7316-713: The annual movement of the glacier. Ogives are formed when ice from an icefall is severely broken up, increasing ablation surface area during summer. This creates a swale and space for snow accumulation in the winter, which in turn creates a ridge. Sometimes ogives consist only of undulations or color bands and are described as wave ogives or band ogives. Glaciers are present on every continent and in approximately fifty countries, excluding those (Australia, South Africa) that have glaciers only on distant subantarctic island territories. Extensive glaciers are found in Antarctica, Argentina, Chile, Canada, Pakistan, Alaska, Greenland and Iceland. Mountain glaciers are widespread, especially in

7440-466: The area as an unrepeatable feat. By contrast, conquistador Pedro de Valdivia , in a letter to Charles V , considered the strait a threat through which rival conquistadors could arrive to challenge his claims. In 1544 Valdivia commissioned Captain Juan Bautista Pastene to explore the coast from Valparaiso to the Strait of Magellan, and installed his personal secretary Juan de Cárdenas in

7564-423: The area of Puerto del Hambre and the navigational conditions in the Strait of Magellan. In a report the expedition recommended that a French colony be established at the strait to support future traffic along the route. Richard Charles Mayne commanded HMS Nassau on a survey expedition to the strait from 1866 to 1869. The naturalist on the voyage was Robert Oliver Cunningham . Charles Darwin requested

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7688-432: The bedrock has frequent fractures on the surface, glacial erosion rates tend to increase as plucking is the main erosive force on the surface; when the bedrock has wide gaps between sporadic fractures, however, abrasion tends to be the dominant erosive form and glacial erosion rates become slow. Glaciers in lower latitudes tend to be much more erosive than glaciers in higher latitudes, because they have more meltwater reaching

7812-445: The bedrock. By mapping the direction of the striations, researchers can determine the direction of the glacier's movement. Similar to striations are chatter marks , lines of crescent-shape depressions in the rock underlying a glacier. They are formed by abrasion when boulders in the glacier are repeatedly caught and released as they are dragged along the bedrock. The rate of glacier erosion varies. Six factors control erosion rate: When

7936-418: The bi-national eastern entrance to the channel while the western entrance is wholly inside Chile. The western entrance of Beagle Channel is divided by Gordon Island into two channels. Some minor islands exist inside the channel among them Snipe Islet and Gable Island . Except for eastern Isla Grande de Tierra del Fuego and Gable Island all islands mentioned here belong to Chile. The Yaghan peoples settled

8060-450: The border as defined in the Treaty of Peace and Friendship of 1984 between Chile and Argentina . Immediately west are Primera Angostura and Segunda Angostura , narrows formed by two terminal moraines of different ages. The Primera Angostura is the closest approach of Isla Grande de Tierra del Fuego to mainland South America. Farther west lies Magdalena Island , part of Los Pingüinos Natural Monument . The strait's southern boundary in

8184-489: The city of Valdivia in the first expedition to enter the strait from the west. Ulloa reached Woods Bay , but faced with the steep coastline and lack of provisions and fearing entrapment in the strait during the winter, he turned around, returning to Chilean ports in February 1554. Valdivia himself never actually reached the strait, as he was killed in 1553 attempting to conquer Araucanía , about 1600 km (994 miles) north of

8308-466: The coast during the winter and moved into the southern Andes in the summer to hunt. The tribes of the region saw little European contact until the late 19th century. Later, European-introduced diseases decimated portions of the indigenous population. It is possible that Tierra del Fuego was connected to the mainland in the Early Holocene (c. 9000 years BP ) much in the same way that Riesco Island

8432-679: The command of Luis de Mendoza ; and La Santiago (75 tons, 32 crew members), under command of Juan Rodríguez Serrano ( João Rodrigues Serrão ). Before the passage of the strait (and after the mutiny in Puerto San Julián ), Álvaro de Mesquita became captain of the San Antonio , and Duarte Barbosa of the Victoria . Later, Serrão became captain of the Concepcion (the Santiago , sent on a mission to find

8556-559: The created ice's density. The word glacier is a loanword from French and goes back, via Franco-Provençal , to the Vulgar Latin glaciārium , derived from the Late Latin glacia , and ultimately Latin glaciēs , meaning "ice". The processes and features caused by or related to glaciers are referred to as glacial. The process of glacier establishment, growth and flow is called glaciation . The corresponding area of study

8680-467: The dead white of the upper expanse of snow." Several small islands ( Picton, Lennox and Nueva ) up to the Cape Horn were the subject of the long-running Beagle conflict between Chile and Argentina; by the terms of a Treaty of Peace and Friendship of 1984 between Chile and Argentina they are now part of Chile. From the 1950s to 1970s several incidents involving the Chilean and Argentine navies occurred in

8804-467: The deep profile of fjords , which can reach a kilometer in depth as ice is topographically steered into them. The extension of fjords inland increases the rate of ice sheet thinning since they are the principal conduits for draining ice sheets. It also makes the ice sheets more sensitive to changes in climate and the ocean. Although evidence in favor of glacial flow was known by the early 19th century, other theories of glacial motion were advanced, such as

8928-483: The deformation to become a plastic flow rather than elastic. Then, the glacier will begin to deform under its own weight and flow across the landscape. According to the Glen–Nye flow law , the relationship between stress and strain, and thus the rate of internal flow, can be modeled as follows: where: The lowest velocities are near the base of the glacier and along valley sides where friction acts against flow, causing

9052-628: The east follows first the shoreline of the Isla Grande de Tierra del Fuego, then the northern end of the Canal Whiteside and the shoreline of Dawson Island . The western part of the strait leads northwest from the northern end of the Magdalena Channel to the strait's Pacific entrance. This is flanked on the south by Capitán Aracena Island , Clarence Island , Santa Inés Island , Desolación Island (Cabo Pilar), and other smaller islands, and on

9176-589: The east side of Tierra del Fuego), Carukinka (the end of the Almirantazgo Fjord), Anika (a channel located at 54° 7' S and 70° 30' W), and Arska (the north side of the Dawson Island). Magellan named the strait Todos los Santos , as he began his voyage through the strait on November 1, 1520, the day of "All Saints" ( Todos los Santos in Spanish). Charles V renamed it Estrecho de Magallanes . Magellan named

9300-454: The east to Darwin Sound and Cook Bay in the Pacific Ocean in the west. Some 50 kilometres (27 nmi; 31 mi) from its western end, it divides into two branches, north and south of Gordon Island . The southwest branch between Hoste Island and Gordon Island enters Cook Bay. The northwest branch between Gordon Island and Isla Grande enters Darwin Sound, which connects to the Pacific Ocean by

9424-418: The essentially correct explanation in the 1840s, although it was several decades before it was fully accepted. The top 50 m (160 ft) of a glacier are rigid because they are under low pressure . This upper section is known as the fracture zone and moves mostly as a single unit over the plastic-flowing lower section. When a glacier moves through irregular terrain, cracks called crevasses develop in

9548-414: The expedition to produce a written account of the lands discovered in order to solidify his claims before the King. Although Pastene's expedition reached only the 41st parallel south , well short of the strait, it discovered San Pedro Bay and the mouth of Valdivia River , where Valdivia would later found the city that bears his name . As Valdivia consolidated his claims, he mentions in a 1548 letter to

9672-465: The foods". The first European contact in this area was evidently the voyage of Ferdinand Magellan . (A report by António Galvão in 1563 that mentions early charts showing the strait as " Dragon's Tail " has led to speculation that there might have been earlier contact, but this is generally discounted.) Magellan led an expedition in the service of the Spanish King, Emperor Charles V , to reach

9796-475: The fracture zone. Crevasses form because of differences in glacier velocity. If two rigid sections of a glacier move at different speeds or directions, shear forces cause them to break apart, opening a crevasse. Crevasses are seldom more than 46 m (150 ft) deep but, in some cases, can be at least 300 m (1,000 ft) deep. Beneath this point, the plasticity of the ice prevents the formation of cracks. Intersecting crevasses can create isolated peaks in

9920-453: The glacier to melt, creating a water source that is especially important for plants, animals and human uses when other sources may be scant. However, within high-altitude and Antarctic environments, the seasonal temperature difference is often not sufficient to release meltwater. Since glacial mass is affected by long-term climatic changes, e.g., precipitation , mean temperature , and cloud cover , glacial mass changes are considered among

10044-428: The glacier will be accommodated by motion in the sediments, or if it'll be able to slide. A soft bed, with high porosity and low pore fluid pressure, allows the glacier to move by sediment sliding: the base of the glacier may even remain frozen to the bed, where the underlying sediment slips underneath it like a tube of toothpaste. A hard bed cannot deform in this way; therefore the only way for hard-based glaciers to move

10168-504: The glacier's surface area, more if the glacier calves icebergs. Ice in the accumulation zone is deep enough to exert a downward force that erodes underlying rock. After a glacier melts, it often leaves behind a bowl- or amphitheater-shaped depression that ranges in size from large basins like the Great Lakes to smaller mountain depressions known as cirques . The accumulation zone can be subdivided based on its melt conditions. The health of

10292-614: The ice at the bottom of the glacier move more slowly than ice at the top. In alpine glaciers, friction is also generated at the valley's sidewalls, which slows the edges relative to the center. Mean glacial speed varies greatly but is typically around 1 m (3 ft) per day. There may be no motion in stagnant areas; for example, in parts of Alaska, trees can establish themselves on surface sediment deposits. In other cases, glaciers can move as fast as 20–30 m (70–100 ft) per day, such as in Greenland's Jakobshavn Isbræ . Glacial speed

10416-420: The ice sheets of Antarctica and Greenland, has been estimated at 170,000 km . Glacial ice is the largest reservoir of fresh water on Earth, holding with ice sheets about 69 percent of the world's freshwater. Many glaciers from temperate , alpine and seasonal polar climates store water as ice during the colder seasons and release it later in the form of meltwater as warmer summer temperatures cause

10540-544: The ice to act as a lever that loosens the rock by lifting it. Thus, sediments of all sizes become part of the glacier's load. If a retreating glacier gains enough debris, it may become a rock glacier , like the Timpanogos Glacier in Utah. Abrasion occurs when the ice and its load of rock fragments slide over bedrock and function as sandpaper, smoothing and polishing the bedrock below. The pulverized rock this process produces

10664-488: The ice, called seracs . Crevasses can form in several different ways. Transverse crevasses are transverse to flow and form where steeper slopes cause a glacier to accelerate. Longitudinal crevasses form semi-parallel to flow where a glacier expands laterally. Marginal crevasses form near the edge of the glacier, caused by the reduction in speed caused by friction of the valley walls. Marginal crevasses are largely transverse to flow. Moving glacier ice can sometimes separate from

10788-411: The idea that meltwater, refreezing inside glaciers, caused the glacier to dilate and extend its length. As it became clear that glaciers behaved to some degree as if the ice were a viscous fluid, it was argued that "regelation", or the melting and refreezing of ice at a temperature lowered by the pressure on the ice inside the glacier, was what allowed the ice to deform and flow. James Forbes came up with

10912-418: The increased pressure can facilitate melting. Most importantly, τ D is increased. These factors will combine to accelerate the glacier. As friction increases with the square of velocity, faster motion will greatly increase frictional heating, with ensuing melting – which causes a positive feedback, increasing ice speed to a faster flow rate still: west Antarctic glaciers are known to reach velocities of up to

11036-423: The infrared OH stretching mode of the water molecule. (Liquid water appears blue for the same reason. The blue of glacier ice is sometimes misattributed to Rayleigh scattering of bubbles in the ice.) A glacier originates at a location called its glacier head and terminates at its glacier foot, snout, or terminus . Glaciers are broken into zones based on surface snowpack and melt conditions. The ablation zone

11160-605: The island on the south side of the strait Tierra del Fuego , which the Yaghan people called Onaisín in the Yaghan language . Magellan also gave the name Patagones to the mainland Indians, and their land was subsequently known as Patagonia. Bahía Cordes is named for the Dutch pirate Baltazar de Cordes . Glacier A glacier ( US : / ˈ ɡ l eɪ ʃ ər / ; UK : / ˈ ɡ l æ s i ər , ˈ ɡ l eɪ s i ər / )

11284-564: The islands along the Murray Channel approximately 10,000 years before present. There are notable archaeological sites indicating such early Yaghan settlement at locations such as Bahia Wulaia on Isla Navarino , site of the Bahia Wulaia Dome Middens . According to a Selk'nam myth the channel was created alongside the Strait of Magellan and Fagnano Lake in places where slingshots fell on earth during Taiyín's fight with

11408-652: The lamines were hunted has been found at some sites, such as Cueva del Medio. Historically identifiable indigenous ethnic groups around the strait are the Kawésqar , the Tehuelche , the Selk'nam and Yaghan people . The Kawésqar lived on the western part of the strait's northern coast. To the east of the Kawésqar were the Tehuelche , whose territory extended to the north in Patagonia . To

11532-531: The land on behalf of the King of Spain. Magellan's chronicler, Antonio Pigafetta , called it the Patagonian Strait , and others Victoria Strait , commemorating the first ship that entered. Within seven years, it was being called Estrecho de Magallanes in honor of Magellan. The Spanish Empire and the Captaincy General of Chile considered the strait the southern boundary of their territory. In

11656-533: The latter. Its major port is Punta Arenas , a transshipment point for Chilean mutton situated on the Brunswick Peninsula . Exemplifying the difficulty of the passage, it took Magellan 38 days to complete the crossing. The eastern opening is a wide bay on the border of Chile and Argentina between Punta Dúngeness on the mainland and Cabo del Espíritu Santo ("Cape of the Holy Spirit") on Tierra del Fuego,

11780-406: The main island. The Selk'nam, Haush, and Tehuelche are generally thought to be culturally and linguistically related peoples physically distinct from the sea-faring peoples. According to a Selk'nam myth the strait was created along with the Beagle Channel and Fagnano Lake by slingshots falling on Earth during the fight of Taiyín with a witch who was said to have "retained the waters and

11904-679: The most deformation. Velocity increases inward toward the center line and upward, as the amount of deformation decreases. The highest flow velocities are found at the surface, representing the sum of the velocities of all the layers below. Because ice can flow faster where it is thicker, the rate of glacier-induced erosion is directly proportional to the thickness of overlying ice. Consequently, pre-glacial low hollows will be deepened and pre-existing topography will be amplified by glacial action, while nunataks , which protrude above ice sheets, barely erode at all – erosion has been estimated as 5 m per 1.2 million years. This explains, for example,

12028-445: The most sensitive indicators of climate change and are a major source of variations in sea level . A large piece of compressed ice, or a glacier, appears blue , as large quantities of water appear blue , because water molecules absorb other colors more efficiently than blue. The other reason for the blue color of glaciers is the lack of air bubbles. Air bubbles, which give a white color to ice, are squeezed out by pressure increasing

12152-555: The north and Tierra del Fuego to the south. The strait is considered the most important natural passage between the Atlantic and Pacific oceans. The strait is approximately 570 km (310 nmi; 350 mi) long and 2 km (1.1 nmi; 1.2 mi) wide at its narrowest point. In 1520, the Spanish expedition of the Portuguese navigator Ferdinand Magellan , after whom the strait

12276-490: The north by Brunswick Peninsula , Riesco Island , Muñoz Gamero Peninsula , Manuel Rodriguez Island , and other minor islands of the Queen Adelaide Archipelago . Two narrow channels connect the strait with Seno Otway and Seno Skyring . A broader channel, Smyth Channel , leads north from the strait between Muñoz Gamero Peninsula and Manuel Rodriguez Island. Francisco Coloane Marine and Coastal Protected Area ,

12400-454: The north coast of the strait. Opposite Pecket Bay is Gente Grande Bay ( Spanish : bahía Gente Grande ) in Tierra del Fuego. On the Atlantic side, the strait is characterized by semidiurnal macrotides with mean and spring tide ranges of 7.1 and 9.0 m, respectively. On the Pacific side, tides are mixed and mainly semidiurnal, with mean and spring tide ranges of 1.1 and 1.2 m, respectively. There

12524-402: The number of observations in the area has increased in recent years. In the more well-defined northeastern course of the strait various bays stand out in its geography. Pecket Bay ( Spanish : bahía Pecket ) is a shallow and somewhat closed bay in the strait located near where Brunswick Peninsula is as narrowest. San Gregorio Bay ( Spanish : bahía San Gregorio ) is an open bay located in

12648-461: The passage, was caught in a storm and wrecked ). San Antonio , charged to explore Magdalen Sound, failed to return to the fleet, instead sailing back to Spain under Estêvão Gomes , who imprisoned the captain Mesquita. Magellan's ships entered the strait on All Saints' Day , 1 November 1520. Magellan named the strait Estrecho de Todos los Santos ("Strait of All Saints") and planted a flag to claim

12772-721: The pooling of meltwater at the base of the glacier  — perhaps delivered from a supraglacial lake  — or the simple accumulation of mass beyond a critical "tipping point". Temporary rates up to 90 m (300 ft) per day have occurred when increased temperature or overlying pressure caused bottom ice to melt and water to accumulate beneath a glacier. In glaciated areas where the glacier moves faster than one km per year, glacial earthquakes occur. These are large scale earthquakes that have seismic magnitudes as high as 6.1. The number of glacial earthquakes in Greenland peaks every year in July, August, and September and increased rapidly in

12896-410: The pressure of the layers of ice and snow above it, this granular ice fuses into denser firn. Over a period of years, layers of firn undergo further compaction and become glacial ice. Glacier ice is slightly more dense than ice formed from frozen water because glacier ice contains fewer trapped air bubbles. Glacial ice has a distinctive blue tint because it absorbs some red light due to an overtone of

13020-432: The region, they would have encountered native equines ( Hippidion ), the large ground sloth Mylodon , saber toothed cats ( Smilodon ) the extinct jaguar subspecies Panthera onca mesembrina , the bear Arctotherium , the superficially camel-like Macrauchenia , the fox-like canid Dusicyon avus and lamine camelids, including the extant vicuña and guanaco . Evidence to suggest that Mylodon , Hippidion and

13144-558: The sea, often with an ice tongue , like Mertz Glacier . Tidewater glaciers are glaciers that terminate in the sea, including most glaciers flowing from Greenland, Antarctica, Baffin , Devon , and Ellesmere Islands in Canada, Southeast Alaska , and the Northern and Southern Patagonian Ice Fields . As the ice reaches the sea, pieces break off or calve, forming icebergs . Most tidewater glaciers calve above sea level, which often results in

13268-511: The south of the Tehuelche across the strait lived the Selk'nam, who inhabited the majority of the eastern portion of Tierra del Fuego . To the west of the Selk'nam were the Yaghan people , who inhabited the southernmost part of Tierra del Fuego. All tribes in the area were nomadic hunter-gatherers . The Tehuelche were the only non-maritime culture in the area; they fished and gathered shellfish along

13392-409: The stagnant ice above, forming a bergschrund . Bergschrunds resemble crevasses but are singular features at a glacier's margins. Crevasses make travel over glaciers hazardous, especially when they are hidden by fragile snow bridges . Below the equilibrium line, glacial meltwater is concentrated in stream channels. Meltwater can pool in proglacial lakes on top of a glacier or descend into the depths of

13516-493: The strait by his participation in the Loaísa expedition , argued before viceroy Antonio de Mendoza in the 1550s for the establishment of an Asia–Mexico trade route and presented arguments against the establishment of rival route of direct trade between Spain and Asia through the strait of Magellan. According to Urdaneta, climate would made passage through the strait possible only during summer and that therefore ships would need to stay

13640-500: The strait with 300 settlers. That winter, it became known as Puerto del Hambre , or "Port Famine", as most of the settlers died of cold or starvation. When Sir Thomas Cavendish landed at the site of Rey Don Felipe in 1587, he found only ruins of the settlement. The Spanish failure to colonize the Strait of Magellan made the Chiloé Archipelago key in protecting western Patagonia from foreign intrusions. Valdivia, reestablished in 1645 , and Chiloé acted as sentries, and as hubs where

13764-401: The strait, trying to ferret out English invaders, while surveying locations for future fortifications. Pigafetta had described the strait as a hospitable area with many good ports, " cedar " wood, and abundant shellfish and fish. In 1584, Sarmiento de Gamboa founded two colonies in the strait: Nombre de Jesús and Ciudad del Rey Don Felipe. The latter was established on the north shore of

13888-473: The strait. In October 1557, Governor García Hurtado de Mendoza sent another exploratory squad of 70 men under the command of Juan Ladrillero . They were charged with mapping the coastline and surveying the region's flora, fauna, and ethnography. On August 16, 1558, Ladrillero arrived in the Atlantic Ocean , becoming the first navigator to cross the Strait of Magellan in both directions. Colonization by

14012-552: The strait. He experienced a 40-day hiatus in the strait due to storms and adverse weather, while piloting the gaff-rigged sloop oyster boat Spray in the first solo global circumnavigation . He wrote about the experience in Sailing Alone Around the World . In 1976, American open water swimmer Lynne Cox became the first person to swim across the strait. Almost 40 years later, on January 17, 2014, Hunter Wright became

14136-570: The strait. Meanwhile, Sánchez de la Hoz was executed in Chile by Francisco de Villagra , one of Valdivia's men. The first map of the Pacific Ocean , Maris Pacifici from 1589, depicts the strait as the only route between the Atlantic and Pacific oceans. Contemporaries differed in their estimation of the strait's significance. In Europe it was viewed by some as an opportunity and a strategic location to facilitate long-range trade, though Antonio Pigafetta seemed to have understood his voyage through

14260-423: The stress being applied, ice will act as an elastic solid. Ice needs to be at least 30 m (98 ft) thick to even start flowing, but once its thickness exceeds about 50 m (160 ft) (160 ft), stress on the layer above will exceeds the inter-layer binding strength, and then it'll move faster than the layer below. This means that small amounts of stress can result in a large amount of strain, causing

14384-438: The surface snowpack may experience seasonal melting. A subpolar glacier includes both temperate and polar ice, depending on the depth beneath the surface and position along the length of the glacier. In a similar way, the thermal regime of a glacier is often described by its basal temperature. A cold-based glacier is below freezing at the ice-ground interface and is thus frozen to the underlying substrate. A warm-based glacier

14508-515: The survey in the second voyage of Beagle under the command of captain FitzRoy, who took Charles Darwin along as a self-funding supernumerary , giving him opportunities as an amateur naturalist . Darwin had his first sight of glaciers when they reached the channel on 29 January 1833, and wrote in his field notebook "It is scarcely possible to imagine anything more beautiful than the beryl-like blue of these glaciers, and especially as contrasted with

14632-518: The waters of the Beagle Channel, for example the 1958 Snipe incident , the 1967 Cruz del Sur incident and the shelling of Quidora the same year. See List of incidents during the Beagle conflict . As a ship's painter, Conrad Martens drew and created watercolour paintings in 1833 and 1834 during the second voyage of HMS Beagle in Tierra del Fuego . The German painter Ingo Kühl traveled three times to

14756-417: The weight of the ice is supported by the underlying water, and the glacier is afloat. Glaciers may also move by basal sliding , where the base of the glacier is lubricated by the presence of liquid water, reducing basal shear stress and allowing the glacier to slide over the terrain on which it sits. Meltwater may be produced by pressure-induced melting, friction or geothermal heat . The more variable

14880-448: The winter in a more northern port. Urdaneta's preference for Mexico may have also been influenced by his links to the Pedro de Alvarado . Following Urdaneta's plans in 1565 the first Manila galleon inaugurated European trade with Asia across the Pacific. Pedro de Valdivia , the conquistador of Chile, managed to have Charles V extend his governorship all the way to the northern shores of

15004-463: The youngest person to swim across the strait at age 17. In June 2004, the USS Ronald Reagan was the first nuclear-powered aircraft carrier to navigate the strait. The strait is approximately 570 km (310 nmi; 350 mi) long and 2 km (1.1 nmi; 1.2 mi) wide at its narrowest point ( Carlos III Island , west of Cape Froward ). The northwestern portion of the strait

15128-458: Was an important supply stop for mariners. It has been claimed that Chile's annexation of the area originated from a fear of occupation by Great Britain or France. In the Boundary treaty of 1881 between Chile and Argentina , Argentina effectively recognized Chilean sovereignty over the Strait of Magellan. Argentina had previously claimed all of the strait, or at least the eastern third of it. In

15252-506: Was back then. A Selk'nam tradition recorded by the Salesian missionary Giuseppe María Beauvoir relate that the Selk'nam arrived in Tierra del Fuego by land, and that the Selk'nam were later unable to return north as the sea had flooded their crossing. Selk'nam migration to Tierra del Fuego is generally thought to have displaced a related non-seafaring people, the Haush that once occupied most of

15376-512: Was situated in a forested zone on the north side of the strait, and was later abandoned. In 1848, Punta Arenas was founded farther north, where the Magellanic forests meet the Patagonian plains. In Tierra del Fuego, across the strait from Punta Arenas, the village of Porvenir emerged during the Tierra del Fuego gold rush in the late 19th century. Until the opening of the Panama Canal , the town

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