Poor Patagonian Cryptids and Glaciers: 2010 hottest year ever

 

Global Warming trend, 2010 hottest year on record. Source: World Meterological Organization

2010, according to the World Meteorological Organization (WMO) was 0.53°C (0.95°F) above the mean temperatures for the period 1961-90. [1]

Furhtermore the Arctic ice is vanishing, despite December being the coldest on record in many European countries for over one century, Arctic sea-ice cover in December 2010 was also the lowest on record. Its surface was only 12 million km² which is 1,35 million km² below the average coverage during the period 1979-2000.

2010 was aobut 0.01°C (0.02° F) warmer than 2005 and 0.02°C (0.05°F) above 1998. Though for the layman, we could say that 2010 was hotter than the other two years (the second and third warmest on recod), considering the error margin for the data (± 0.09°C or ± 0.16°F), all three are tied from a statistical point of view. Nevertheless, since 1998 we have experienced the three hottest years since temperatures have been recorded scientifically.

Interestingly the global temperature increase is not uniform. The WMO stated that:

2010 was an exceptionally warm year over much of Africa and southern and western Asia, and in Greenland and Arctic Canada, with many parts of these regions having their hottest years on record.
Over land few parts of the world were significantly cooler than average in 2010, the most notable being parts of northern Europe and central and eastern Australia.[1]

This hotter world with indeed have a negative impact on animals and plants, and, of course Patagonian cryptids. If the area becomes drier or warmer and tree coverage recedes the impact could be severe for Patagonian creatures. Glaciers are melting at a quick pace. The environment is shifting as you read this (see this article at the NY Times website on how animals are threatened by climate change).

What are you doing to help curb climate change?

Sources.
[1] World Meteorological Organisation, (2011). Press Release No. 906. 2010 Equals record for world’s warmest year , 20.01.2011.
[2] Rosenthal Elisabeth, (2011). For Many Species, No Escape as Temperature Rises. New York Times. 21.01.2011

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia

2011 International Year of Forests Copyright 2009-2011 by Austin Whittall © 

"Glacier Law" approved by Congress

 

The Argentine Senate approved the "Glacier Law" (Ley de Glaciares) which restricts mining activities in Argentina forcing it to be environmentally friendly.

The law which is more permissive than the original project passed by the Lower Chamber of Congress (Deputies) but still puts restraints on all open-pit mining in high mountain areas by or close to glaciers.

Now we must wait and see if the President vetoes the law or passes it.

Further reading

See Greenpeace Argentina's website page about the Glacier law (in Spanish), or in English, you can see the article posted at BBC's site.

Find out about the environmental problems that Patagonia faces.

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Lea este post en español

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia

2010 International Year of Biodiversity Copyright 2009-2010 by Austin Whittall © 

Another Paleo-Lake (Puelo)

 

Paleo Lake ca. 1000 BP. By Barzi, A. [1]

When I posted on Vanishing Rivers I mentioned a great Paleo-lake that had formed at the end of the last Ice Age in northern Patagonia. In other posts, I had mentioned also mentioned deglaciation and the formation of the current Patagonian eco regions.

Today I came across a very interesting map by Mr. Alejandro Brazi, at his website which deals with the geography of the small village of El Hoyo and its surrounding areas.[1] It shows how the area that is now occupied by lakes Puelo, Epuyén and the valleys of the rivers Epuyén and Azul, were flooded during the end of the last Ice Age producing a very large paleo-lake.

The lake drained just as it does in the present, to the west, into the Pacific Ocean through a narrow pass in the Andean mountains.

The interesting part of this is that the Patagonian Plesiosaur was said to have been sighted in the Puelo-Epuyén rivers basin in the early 1920s. (see my map showing the current lakes and compare it with the one shown above.

Did the receding waters capture some megafaunal beast and restrict it, keeping it captive in the now smaller lakes?
Dit it originally swim up the Puelo River from the South Pacific Ocean, during the days when Puelo and Epuyén lakes were merged in the giant paleo-lake?

By the way, there have been reports of "monsters" in the Puelo River.

We will never know (neither can we know if there is -or was- a cryptid lake creature here or if it was really sighted in 1922.)

Bibliography.

Barzi, A. Descripcion de El Hoyo. Geografia Fisica

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia

2010 International Year of Biodiversity Copyright 2009-2010 by Austin Whittall © 

Vanishing rivers and Plesiosaurs

 
I previous posts (List of my plesiosaur entries) I have discussed Nahuelito the "reptilian" cryptid that is said to live in Lake Nahuel Huapi. I have dismissed the possibility that the creature (if it exists) is an extant Mesozoic reptile, but I never gave a detailed explanation or proof to support my position. Until now.

Today we will look into the origin and evolution of Lake Nahuel Huapi and the mystery of a "lost" river in Patagonia. Both of which may shed some light on the plesiosaur business.

First there was fire

The mighty Andes are a mountain range that span the entire west coast of South America. They are being pushed upwards by the subduction of the Nazca Plate beneath the westward moving South American Plate. This is the longest subduction zone in the whole world and is over 7,000 km (4,350 mi.) long. This mighty collision shortens and crumples the South American Plate and forces the Andes constantly upwards.

The subduction process began during the late Mesozoic and early Cenozoic eras (at about the same time or shortly after the dinosaurs disappeared) and has continued since then. In the Patagonian Andes, which extend from roughly 39°S to 52°S, the uplift began during the Miocene period (23 to 5 Million years ago).

It was in this period that the area where modern Lake Nahuel Huapi lies was folded and driven upwards. Mighty mountain ranges were formed. These run with a North to South orientation and this conditioned regional drainage. Massive volcanos were also formed, and are still the highest mountains in the area (i.e Mount Tronador and Mount Lanin, both over 3,500 m – 11,500 ft.). These new mountains were much higher than they are nowadays, erosion had not yet worn them down. They had steep slopes and sharp "V" shaped valleys separated them.

Then there was ice

Regular snow melt in summer and rain began the erosive process that created the first streams and rivers, which ran eastwards towards the Atlantic on the oriental side of the Andes, and west into the Pacific ocean on the occidental side. The continental water divide rested on the highest summits.

A proto-drainage system was formed. After several millions of years, a gradual cooling began, and the mountain tops began gathering more and more snow, which turned to ice and formed glaciers which then flowed downhill from these steep mountains into the valleys that separated them.

The glaciers, like gigantic bulldozers crunched the rock with their tremendous weight and abraded the valley floor and mountain slopes, making them wider and deeper and giving them the characteristic “U” shape of glacial valleys.

Ice age chronology at Nahuel Huapi

The first recorded Ice Age is the Pichileufu Glaciation named after the Pichileufu River which runs some 20 km south east of Bariloche city in a northern direction towards Limay River.

Remains of glacial drift (drift is any kind of rock transported by a glacier) have been found 350 to 500 meters above modern Lake Nahuel Huapi (up to 1,200 m above sea level – 3,900 ft.).

These glaciers were probably ice “lobes” that extended beyond the mountain range into the steppe, they were not very thick.[3]

This glaciation was followed by a long interglacial period during which the recently hewn glacial valleys were eroded by rainfall and rivers resulting in deeper and wider trenches. These would later serve as conduits for the glaciers during the following Ice Ages.[3]

The Andes in the meantime kept on pushing higher (1 – 0.8 million years ago) causing more ice to accumulate and defining the gradient along which ice would flow.

At about that time, the second glacial period (El Cóndor began. It reached eastwards towards the Atlantic Ocean, along the steppe and west right up to the shores of the Pacific Ocean. Warming caused the glaciers to melt and retreat once more.

The final ice age or Nahuel Huapi glaciation began some 75,000 years ago; the ice sheets reached their maximum coverage some 20,000 years ago, when once again warming caused the ice to melt. Sporadic “Tardiglacial” advances some 10,000 years ago (during the period known as Younger Dryas in the Northern Hemisphere) puncutated the ice’s retreat.

Since then, the global warming trend has melted the valley glaciers in this area and permanent ice coverage can only be found on Mount Tronador (with several glaciers) and on the summits of other high mountains.[3]

Map showing extent of glacier coverage at Lake Nahuel Huapi. Copyright © 2007 by Austin Whittall. Adapted From [1].

Then there was water

It is not easy to imagine extensive sheets of ice at least 2 km (1.25 mi.) thick moving slowly downhill towards what is now the edge of the Patagonian steppe, some 100 km (60 mi.) from the Continental Divide. These were massive glaciers whose flow was guided by the valleys formed during previous glaciations and the blocking effect of transversal (north-south) mountain ranges.

The west – east slope down which the glaciers moved was blocked by these north-south ranges. In some places such as the current basin of Lake Nahuel Huapi (like most Patagonian lakes it has an east-west orientation) the ice managed to leave the Andes behind and push outwards along the steppe.

Glacial Ice melt helped to form the paleo-valleys of most modern rivers draining towards the Atlantic, such as the Colorado, Negro, Neuquén and Limay rivers. These flowed along pre-existing faults (such as the Negro river along the Huincul fault) or along the proto-rivers that drained the area before the Ice Ages.

Towards the end of the last Ice Age some 16,000 to 18,000 years ago, ice melt generated huge quantities of water that were dammed in by the former glacier’s terminal moraine.

Moraines are crescent shaped mounds or accumulations of rocks that can be found at glacier’s tips and sides (frontal and lateral moraines), they are the rocks “bulldozed” by the advancing ice and act as dams to the melting glacial ice.

Water accumulated in the great depression that the glaciers had excavated, flooding the whole basin and forming a lake, which is known as Elpalafquen (derived from the language of the local Mapuche natives: Elpa = the beginning and Lafquen = lake), the “lake of the beginning”.

Elpalafquen's water level was much higher than that of modern day Lake Nahuel Huapi and therefore this paleo-lake and covered a larger area than the current Lake Nahuel Huapi (which has a surface area of 550 km² or 212 sq.mi.).

It extended across current low-lying areas and meadows beyond what are now its shores, encompasing other lower lying lakes that now flow into Nahuel Huapi such as Lake Correntoso, Lake Espejo, Lake Moreno, Lakes Gutierrez and Mascardi among others.

Its eastern terminus was blocked by the natural dam of its terminal moraine. The excess water (melting snow on the surrounding mountains and rain) flowed over this moraine into what now is the Limay River and from there into the Negro River and on towards the Atlantic Ocean.

To the west, straddling the main Andean range, the melting ice cap still blocked the valleys that led to the Pacific Ocean. Later, a western outflow appeared along a paleo-River, the Lower Manso, which now drains part of this basin into the Pacific (the low lying Manso Pass, at 400 m above sea level [1,300 ft.] - 41º30’S, 71º50’W).

Breach and flood

About 13,200 years ago, melting was accelerated during the Late Pleistocene period and probably a sudden volcanic or tectonic event created a cataclysmic breach of the eastern moraine. The dam broke and vast quantities of water poured downstream along the Limay paleo-River valley. [4]

The western end also lost its ice “plug” at the same time and contributed to drastically drop Elpalafquen's level.

The outflow had several consequences:

1. The paleo-lake split up into several smaller ones (that we can still see nowadays).
2. Nahuel Huapi, the largest among them continued flowing into the Atlantic. Lakes Gutierrez, Moreno and Correntoso -among others- flowed downstream into the Nahuel Huapi.
3. Other lakes (Mascardi, Guillermo, Steffen, Hess, Fonck, etc. changed their drainage westwards into the Pacific Ocean. The continental divide had moved east far from the highest mountains, an anomaly that would later create tension between Argentina and Chile when they defined their mutual border in the late 1800s.
4. Devastation along the Limay and Negro river valleys which may have contributed to give them their current shape.

Shorter route for the "Plesiosaur"

Before this cataclysmic event it is very likely that Elpalafquen spilled east into the steppe, and that occasional large floods of glacial melt origin swept through that region. Perhaps it had a small outlet flowing due east with a constant flow.

There is an elevated region, with several ridges running north to south to the east of Lake Nahuel Huapi, these are the sources of several rivers, some that drain north into the Limay basin (Comallo and Pichi Leufu rivers), others south towards the Chubut basin and others west into Nahuel Huapi.

They are not to high (roughly 1,000 m – 3,300 ft.) so a flooded Elpalafquen could well have overflowed and washed across them draining into the lower lands that lie to the east and that currently drains into a closed basin (see my posts on this area's Lake Carrilafquen, home to a "cuero" monster).

This idea was put forward by Casamiquela [2], who wrote about the geology of the Huahuel Niyeo River valley, which, according to him [2] is “one of the stretches of the 'ancient Limay River Valley'”. He adds that this Limay paleo-river, instead of following its current SW-NE course, may drained eastwards and carried Andean rocks and gravel (“rodados tehuelches”) into the area, during a “great deglaciation”.

The gravel trail

These Patagonian gravels (known in Spanish as “rodados patagónicos” or “rodados tehuelches” cover most of the surface of Patagonia, it is a layer of gravel which can reach a thickness of tens of meters (hundreds of feet) composed of boulders and pebbles of a wide range of sizes.

which was first mentioned by Charles Darwin who was intrigued by them as he had seen them in northern Patagonia (by the Negro and Colorado rivers) and again in the south at Deseado and Santa Cruz rivers. He wrote:

By whatever means the gravel formation of Patagonia may have been distributed, the vastness of its area, its thickness, its superficial position, its recent origin, and the great degree of similarity in the nature of its pebbles all appear to me well deserving the attention of geologists, in relation to the origin of the wide-spread beds of conglomerate belonging to past epochs [5]

Darwin believed that in ancient times erosion (ice, water) had deposited vast amounts of pebbles at the foot of the Andes which were then spread out across Patagonia by the sea (wave action), which he believed covered most of Patagonia. As the continent rose, the gravel came above sea level.

Darwin's theory is not favored nowadays, but even today the origin of this gravel is debated. The general consensus is that they originated during the Pleistocene epoch, during the glaciations, which eroded and worked the rocks and boulders into these egg shaped stones. Water from ice melt (rivers, streams and floods) later dragged them across Patagonia.

As the following map shows, these gravels are found virtually everywhere and mostly following the courses of current rivers (the middle course of Chubut River as well as Limay and Neuquén rivers are exceptions. Why?). They are also found along the sea shore (perhaps due to oceanic dispersion of gravel washed into the ocean by the rivers).

Distribution of Patagonian Gravel and the hypothetical Elpalafquen river. Copyright © 2010 by Austin Whittall. Adapted from [7].

Did Eplalafquen drain eastwards along the northern foot of Somuncurá plateau in a broad arch through what are now closed basins fed streams that flowed north from the plateau? Could it have reached what is now the bay of San Antonio in the Gulf of San Matías?

The distribution of Patagonian gravel in the map shows that it may be possible (note the curved red line of the hypothetical river that drained Elpalafquen – shown as a red circle), furthermore it explains the gravel spread to the southeast of Elpalafquen.

There are some areas along the river's course that lack gravel (i.e. San Antonio on the Atlantic.) but here, marine transgression has placed sediment above the gravel.

The course of this river would roughly coincide with National Highway No. 23 and the Railroad that connects Bariloche with San Antonio Oeste. This is quite obvious as both road and tracks run along the lower lying areas north of Somuncurá plateau, which is where the river would have been in post-glacial times.

Somuncurá is home to a strange relict fish, the naked minnow.

If so, this hypothetical river would have followed the course shown in red in the following map. I have also shown (red circle) the approximate area that the paleo-lake would have occupied and its southwestern drainage through the Manso River into Chile.

Elpalafquen's river draining towards the Atlantic. Copyright © 2010 by Austin Whittall

This river would have been very short lived (decades? centuries?) and when the Limay plug broke, the lower water level at Nahuel Huapi maked its end. Perhaps intermitent flow from Carilafquen paleo-lake could have kept it flowing for longer, but the link with the Andean lakes would have been severed.

Proof. The native myths.

The native myth mentioned by Clemente Onelli in his 1903 book (he got it from first hand sources before the local natives traditions became lost forever). I will quote him fully:

I descended into a fertile and wide canyon that extends till it is out of sight towards the east and whose other tip, on the lake is now blocked by glacier hills; the native tradition says that, in very old times, along this gully a river flowed, it exited the lake [Nahuel Huapi] and reached the sea in front of the gulf of San Antonio [Gulf of San Matías]. [6]

Ancient maps offer additional proof, I will post on them in my next entry. By the way, there are several "missing" or "lost" rivers in Patagonia, I will post on them too.

The sea monster

Having said all this, it could be reaonably possible this direct route along a hypothetical Elpalafquen drainage river would join the Ocean to the Andes. It would also be a far shorter than that of the Negro and Limay rivers. This is, I believe an interesting option and has some reasonable proof in its favor.

Now the "low probability" events:

If so, this Elpalafquen river could also have allowed some mysterious sea creature to swim upstream to the newborn glacial paleo-lake and make it its abode.

This would require an extant plesiosaur that somehow managed to survive extinction, reproduce and live in the oceans some 65 million years and then, during the small temporal window of this river's existence, find it and swim upstream to paleo-Lake Nahuel Huapi an adapt to a freshwater environment. Perhaps an impregnated female would suffice or to keep the species alive, a male and female couple would be required.

Yes, the chances of this happening are virtually nil.

Bibliography.

[1] Kodama, K., Rabassas, J., Evenson, E., Clinch, M.(1986). Paleomagnetismo y edad relativa del drift Pichileufu en su area tipo, San Carlos de Bariloche, Rio Negro. Asociación Geológica Argentina, Revista. XLI (1-2): 165-178. Fig. 1. pp. 167.
[2] Casamiquela, R., (1969). Historia Geologica del Valle de Huahuel Niyeo Area Extraandina del Suroeste de la Provincia de Rio Negro, República Argentina (Con énfasis en el Pleistoceno). Asociación Geológica Argentina, Revista. Jul-Sep. pp. 287+
[3] Planas, F. (2009)Las glaciaciones en el norte de la Patagonia Desde la Patagonia difundiendo saberes. V. 6 - Nº 9. Online.
[4] Del Valle, R., Tatur, A., Rinaldi, C. (2007) Cambios en lagos y circulación fluvial vinculados al calentamiento climático del pleistoceno tardío-holoceno temprano en Patagonia e isla 25 de Mayo, islas Shetland del sur, Antártida. Revista de la Asociación Geológica Argentina 62 (4): 618- 626.
[5] Darwin, C., (1851). Geological observations on coral reefs, volcanic islands and on South America: being the geology of the voyage of the Beagle, during the years 1833 to 1836. Smith, Elder & Co., pp. 25.
[6] Onelli, C., (2007). Trepando los Andes (1903. Buenos Aires: Ed. Continente. pp. 33
[7] Martinez, O., Rabassa, J., Coronato A., (2009). Charles Darwin and the first scientific observations on the patagonian shingle formation (Rodados Patagónicos). Rev. Asoc. Geol. Argent. v.64 n.1 Buenos Aires abr. 2009

Further reading

Caldenius, C. 1932. Las glaciaciones cuaternarias en la Patagonia y T. del Fuego. Dir. Gral. Minas y Geología, Publ. 95, 150 pp., Buenos Aires
Feruglio, E. 1949-1950. Descripcion geologica de la Patagonia. T.3, YPF, Buenos Aires
Fidalgo, F., 1982. Glaciaciones en la Patagonia. INQUA Comm. Litol. & Genesis Quat. Depos., South Amer. Reg. Meet. Excursión Fieldbook, p. 9-29, J. Rabassa, de., Departamento de Geografia, Universidad Nacional del Comahue, Neuqu´n.
Rabassa, J. 1974. Geologia de la región de Pilcaniyeu-Comallo, Pcia. de Río Negro, Argentina. Tesis doctoral N. 331, Facultad de Cienc. Nat. y Museo, Univ. Nac de La Plata y Publ. N. 17, Depto. Rec. Nat. Energia, Fundacion Bariloche: 128, San Carlos de Bariloche.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia

2010 International Year of Biodiversity Copyright 2009-2010 by Austin Whittall © 

"Patagonian Dragon" the Andiperla willinki

 

Andiperla willinki is a very rate insect belonging to the order of Plecoptera, commonly known as stoneflies. Its common name is "Patagonian Dragon" (I do not know why).

They are widely distributed around the world and over 1,500 species have been recorded. They are winged insects and belong to one of the most primitive groups of this kind of insect.

Andiperla willinki "Patagonian Dragon". From [6]

Today we are posting about one of these, belonging to the Gripopterygiidae family, the Andiperla willinki or Patagonian Dragon was first described in 1956 by French biologist Aubert Willink, based on a specimen found at the Upsala Glacier in Santa Cruz Province, Argentina.[1] (More on Patagonian glaciers Here.)

This creature is indeed incredible because, unlike the other members of the order, (which are winged insects), this one is wholly apterous (has no wings), it does not need them as it is well adapted to its very special environment.[2]

Furthermore it also lacks ocelli (tiny eyes) but it has well developed eyes (large) which help it see in the dimly lit habitat that it has adapted to.[2]

Though it can be found under stones in the Southern Patagonian Andes up to a height of 1,000 m (3,300 ft.), [2] its most incredible environment is the Southern Ice fields in Santa Cruz Province, Argentina. Recently it has also been found in other lakes and glaciers close by such as Moreno and Viedma and in Paine, Chile.

Andiperla willinki "Patagonian Dragon". From [4]

This tiny insect barely 20 mm long (0.8 in.) it lives its whole life within the ice of the Glaciers of the Souhtern Ice Field. It eats the tiny algae that live in the ice.

To avoid freezing, its body has a natural anti-freeze based on glycerol (similar to what is used in our car’s cooling systems to avoid it bursting when temperatures drop below freezing point).

They have the peculiarity of lacking empodia (tiny claws at the tip of their legs), a feature found only in one other stonefly species in the whole world, the R. nudipes. This may be due to the fact that both species live in cold mountainous areas and the lack of empodia may help them conserve heat in their frigid habitat.[5]

A French documentary team found it in the icy water at the Chilean National Park of Torres del Paine, 40 m (130 ft.) below the surface in a crevasse filled with freezing water.[3]

Little is known of them, and further study is necessary.

Bibliography.

[1] Willink, Aubert (1956). Plécoptére nouveau des Andes de Patagonie. Mitteilungen der Schweizerischen Entomologischen Gesellschaft 29 pp. 229-252.
[2] Mani, S., (1968). Ecology and biogeography of high altitude insects. Springer. v.4. pp.401.
[3] Documental filmado en patagonia chilena logra doble reconocimiento. 09.11.2005.
[4] Khoshima Laboratory.
[5] McLellan, I., D. Rakiuraperla nudipes McLellan 1977.
[6] Heckman, C., (2003). Encyclopedia of South American aquatic insects: Plecoptera. Kluwer Academic Publishers: Dodrecht. pp.232


Copyright 2009 by Austin Whittall ©

Patagonian Monsters

Patagonian Glaciers - What they look like

 

We have mentioned (Here)the glaciers and the Icefields, but one thing is to write about them, another is to see them.

I have been to the "Los Glaciares National Park" in Santa Cruz Province, Argentina, twice. In 2004 and 2007. Both in mid winter. A freezing but delightful experience. The park includes several lakes, the largest of which are Argentino and Viedma - and for both of them there have been reports of "lake creatures" (I will post on them later).

I took hundreds of photographs of several glaciers including the two most famous ones, Perito Moreno and Upsala (below are two of these photos), both on Lake Argentino.

Perito Moreno glacier is 5 km (3 mi.) wide and its ice walls are over 60 m (180 ft.) high above the lake level, and below it, they dig deep into the bedrock of the lake's bottom. Over 400 m (1,300 ft.) below the lake's surface. Actually the base of the glaciers are over 200 m (700 ft.) below sea level because these lakes are at a very low altitude above sea level (184 m - 603 ft.).

The photograph shows the southern face on Brazo Rico which, joins the main body of the lake by passing in front of the glacier through the "canal de los tempanos" (iceberg channel).

Perito Moreno advances slowly blocking the channel until the water pressure builds up and breaks the ice dam. A surge of water then flows into the northern part of the lake to flow into the Atlantic ocean.

Regarding Upsala glacier, the photograph shows one of its two faces (each are about 4 km long - 2.5 mi.). It is also 60 m high. A very large chunk of ice.

Perito Moreno Glacier (south face) - Southern Icefield. Copyright © 2007 by Austin Whittall

Upsala Glacier (western face) - Southern Icefield. Copyright © 2007 by Austin Whittall

Map of Southern Santa Cruz Province showing Parque Nacional los Glaciares (vertical stripes), Lake Argentino and Upsala (in red) and Perito Moreno (in blue) Glaciers. From a map by IGM.

Further reading:

Chinni, Guillermo, (2004). Glaciares del Lago Argentino y el Chalten. Del Perito Moreno al Marconi. B. Aires: Zaguier & Urruty Publications.




Copyright 2009 by Austin Whittall ©

Patagonian Monsters

Lake Monsters - The origin of their habitat. Part 1

 

If the Patagonian lakes are home to lake “monsters” and mysterious creatures, we can learn more about these cryptids if we study the lakes themselves and their origin.

Patagonian lakes, both in Argentina and Chile are mostly located along the Andes mountain ranges which run in a north-south direction and are cut on an east-west direction by many valleys, some of which are filled with deep freshwater lakes. A few exceptions are lakes set in the steppe (i.e. Lake Colhue Huapi – which is fed by water from the Andean snow melt) some of which lake drainage and are fed by the scarce rainfall.

These Andean lakes were carved by the glaciers during the Ice Ages.

Ice Ages and the formation of lakes

Sixteen different “Ice Ages” have been recorded in the southern tipo of Patagonian mainland during the last 2 million years, and at least six in Tierra del Fuego Island during the last million years.[1]

The most severe of these was the “GGP” or Gran Glaciación Patagónica (Great Patagonian Glaciation), about 1 million years ago. During this event, the ice sheets reached the Atlantic Ocean at the area of the Strait of Magellan. Later glacier advances extended for several hundred kilometers but did not reach the sea (i.e up to 300 km in Tierra del Fuego). [1]

All of Patagonia is strewn with rounded boulders and pebbles created by the glaciers and their melt waters.

The last glacial event began about 25,000 years ago and most of southern Patagonia was covered with glaciers or a frozen tundra with permafrost. Only on certain warmer spots along the sea shore did the Nothofagus forest survive.[1]

Below are some maps showing the areas that were covered by the ice sheets:

Northern Patagonia. From the Internet [*]
The striped area was covered by glaciers. The dotted red line is the border between Chile and Argentina.

Northern Patagonia coverage, detail. From the Internet [*]
In gray the icefields, in black, current glaciers. Arrows show the direction of the ice sheet flow.

Southern Patagonia Ice coverage- note extant icefields in green. From [3].

Ice starts to melt: paleolakes

After deglaciation, the forests retreated together with the glaciers, their source of water, to occupy their current habitat in the Andes, leaving the now arid Patagonian plateau to shrubs and dwarfish bushes (a dry steppe).

During the ice ages, the glaciers and their moraines formed large natural dams that contained what are known as paleolakes. These large bodies of water had very high water levels and drained towards the Atlantic Ocean. The wide and deep valleys that cross the Patagonian steppe from west to east witness the might of the rivers that drained these lakes. Now most of these valleys hold small rivers (i.e. rivers Chico, Coyle, Gallegos) and some even run dry before reaching the coast (i.e. Deseado River).

During the late Pleistocene epoch (between 13,200 and 7,800 years ago), climate grew warmer and the glaciers began melting. This changed not only the weather and local ecology, but also affected the landscape as the paleolakes fragmented into smaller ones and their water level dropped, in some cases below the eastern terminal moraines, blocking their outflow into the Atlantic Ocean, and causing them to empty westwards into the Pacific Ocean.[2]

These paleo lakes were, from north to south, the following [2]

Elpalafquen 41° S. Was a vast lake system that drained through the Limay River into the Atlantic (which still drains many lakes of the eastern slope of the Andes such as Nahuel Huapi, Espejo, Correntoso, Gutiérrez, Moreno, Traful, etc.) it broke up about 13,200 years ago and some lakes began draining into the South Pacific through the Manso River (such as Mascardi, Steffen, Fonck, Guglielmo, Césares, Hess, etc.).

Caldenius 47-48° S, included current lakes Azara, Belgrano, Mogote, Nansen, Volcán and Burmeister, all of which are now part of the Argentine Perito Moreno National Park. It drained into the Atlantic until ten thousand years ago when it also began to drain through a channel cut through the Andes. Its level was over 100 m (300 ft.) higher than the current water level of Lake Belgrano.

Fuegian paleolake 54-55° S, began melting 7,800 years ago. It comprised lakes Fagnano, Yehuin and Chepelmut as well as the Esperanza bog. Nowadays only Esperanza drains towards the Atlantic through the del Fuego River. The other three lakes drain into the Strait of Magellan.

Remnant glaciers

All that remains of these imposing glaciers that once covered a very large surface of Patagonia are two continental ice sheets covering an area of 21,000 km2 (8,110 sq. mi.). These are the third biggest extensions of continental ice after Antarctica and Greenland. Located roughly 73°W and between 47° and 51°30’ S they are fed by the abundant winter snowfall and maintained by frost most of the year; however, they are now imperiled by climate change as can be seen in the following photographs of Upsala Glacier (Southern Icefield), comparing the same view in 1928 and 2004:

Upsala Glacier (49°50' S, 73°17'W) has a surface area of 870 km² (340 sq.mi.) and a length of about 60 km (37 mi.), making it the third largest Southern Hemisphere glacier outside Antarctica,and South America's longest glacier. It is shrinking rapidly. See Fig. 53 [3] which shows a map with the retreating front of this glacier (1968-1995).

See my photograph of the glacier in my post Here.

Northern Patagonian Icefield (47°00’S, 73°39’W) is about 120 km long (74 mi.) and 40-60 km wide (25 – 37 mi.) and covers an area of 4,200 km² (1,640 sq. mi.), capping the Andes.

Southern Patagonian Icefield (between 48°50’S and 51°30’S is about 40 km wide and covers a larger area (13,200 km², about 5,150 sq.mi.). This is the largest mass of ice outside of the Antarctic.

The remaining glaciers are distributed along the tall Andean peaks in smaller icefields, the larges of them is on Tierra del Fuego Island and has a surface area of about 2,500 km² (975 sq.mi.) it straddles Darwin Cordillera and Mount Sarmiento.

Impact on cryptids

From the above we can see that there were no lakes before the Ice Ages (2 million years ago max.). They must have been excavated in a gradual process, by which each successive glaciation dug deeper trough shaped valleys which during the warmer inter-glacial periods filled with water. And were repeatedly filled up again with ice sheets hundreds of meters thick during each new glacial period.

This must have exterminated any animals attempting to colonize these lakes until the last deglaciation some 10,000 years ago.

The current lakes are the remnants of gigantic paleolakes that broke up and split, shedding their water into both oceans. Their fauna prior to the introduction of salmonids in the 1900s was the local endemic Patagonian species, which hitch-hiked their way from lake to lake perhaps on the feet or feathers of the local water fowl.

This excludes the existence of any large "non-fish" freshwater creatures such as plesiosaurs and so on.

Large tropical mammals could have moved into the now arid Patagonia, but if they were aquatic creatures accustomed to the warmer and more humid conditions prevailing to the north of Patagonia, we must identify how they crossed the dry barren areas that now separate the Patagonian Andean forests from these northern tropical areas.

That is what we will do in our next post Here.

Bibliography.

[1] Coronato, A., Borromei, A., and Rabassa, J. Paleoclimas y Paleoescenarios en la Patagonia Austral y en Tierra del Fuego durante el Cuaternario.
[2] Del Valle, R., Tatur, A., and Rinaldi, C., Cambios en lagos y circulación fluvial vinculados al calentamiento climático del Pleistoceno Tardío-Holoceno Temprano en Patagonia e Isla 25 de Mayo, Islas Shetland del Sur, Antártida. Revista de la Asociación Geológica Argentina 62 (4): 618- 626 (2007)
[3] USGS. Historic Fluctuations of Outlet Glaciers from the Patagonian Ice Fields. Fig. 54.

Further Reading:

Glasser, N., Harrison, S., Winchester, V., and Aniya, M. Late Pleistocene and Holocene palaeoclimate and glacier fluctuations in Patagonia . Global and Planetary Change, Volume 43, Issues 1-2, August 2004, Pages 79-101.



Copyright 2009 by Austin Whittall ©

Patagonian Monsters