The WE - State of Planet

The continent of Antarctica is 14 million square kilometers in area, including its permanent outer shelf ice. A narrow peninsula curves from the central continent, its northern tip reaching beyond the polar circle into the waters of the Antarctic convergence.

Ice shelves, ice piedmonts, ice rises, glacier tongues, iceberg tongues, sea-pack ice, open seas, islands, this is the Antarctic outer scenery. When the surrounding seas freeze in winter, sea ice more than doubles the world’s greatest cover of ice.

Antarctica for much of its history has been free of ice.   The core rock was once a part of a much larger landmass that had forests and lakes. Significant deposits of coal have been found in two areas, in the Transantarctic Mountains and in the Prince Charles Mountains.

Glossopterids are an extinct group of plants that have sometimes been considered to be ancestors of the flowering plants.   These plants were a diverse group that thrived throughout the temperate forests of the Southern Hemisphere, including Antarctica, around 250 million years ago.   Petrified Glossopteris seed fern has been found, as have fossilized tree stumps, roots, stems, and leaves of fossil southern beech wood.

Almost the entire continent is covered by deep ice making it extremely difficult to obtain fossilized evidence from past geologic ages, but dinosaur bones have been found on Ross island and in other areas, indicating they roamed this region during the Jurassic and Cretaceous age.   On Mt. Kirkpatrick, at a height of 14,000 feet, a team discovered the bones of a dinosaur, a flying pterosaur, a tritylodont, a prosauropod and the remains of other ancient animals.

Antarctica began splitting from its adjoining lands about 96 million years ago.   There was likely a land bridge from South America, a series of small mountains, but as the land drifted southwards the mountain peaks became submerged.

45 to 30 million years ago Antarctica became completely encircled by the much colder Antarctic current.   Although there have been cycles of temperature increase since this time, the abundance of vegetation began to enter a world of ice.   Today this continent is where the lowest surface temperatures on Earth are recorded.   Scientists at the base station at Lake Vostok registered a temperature of -91 degrees Celsius in 1997.

Current Weather

Mountains

Mt. Kirkpatrick, approximately 650 kilometers from the Geographic South Pole, is part of the mega-range of mountain peaks we call the Transantarctic range.   The base of the mountains — laid on the ocean bed 750 million years ago — began to uplift for their most recent time 45 million to 30 million years ago.

The Theron Mountains, the Shackleton Range, the Pensacola Mountains, the Thiel Mountains, Dufek Massif, the Horlick Mountains, Whichaway Nunataks, the Queen Maud mountains are high peaks, merely that exposure we can see — the base of the land is covered by ice that began as far back as 15 million years.

These seen peaks form a 3,200 kilometer long chain of mountains that runs from Coats Land on the Weddell Sea to Cape Adare in Victoria Land.

There are several mountain ranges around the edges of the continent.   The hills of Queen Maud Land, with heights up to 3,000 meters, the Enderby Land summits, with heights above 2,000 meters, and the spectacular Prince Charles Mountains, a series of ranges and isolated nunataks, that rise beside the largest glacier in the world, the Lambert Glacier — 25 miles wide and 250 miles long.

The Ellsworth Mountains, the tallest range, are on the northern side of the vast East ice sheet.   Here, at 4,897meters, 16,067 feet above sea level, is the Vinson Massif.   The massif — includes the highest peak in Antarctica — looks over an amazing, stunning flow of snow and ice extending far, far across this remote and isolated land.

Ice Sheets

The east side of the continent has some of the oldest rocks known on Earth — close to 4 billion years at its core shield — 40 to 50 kilometer thick.

The west side of the continent is a mosaic of 30 kilometer islands of continental crust.   This patchwork of crust formed when tectonic plates began moving at the splitting of the super continental landmass from which Antarctica separated.

Two ice sheets developed — the East Antarctic, or Greater Ice Sheet, and the West Antarctic, or Lesser Ice Sheet.   The two sheets are separated by the Transantarctic Mountain range.   On the east rock bed the early ice sheets were confined to the interior.   It is believed the first large eastern ice sheet existed around 40 million years ago.   Several million years later a western side ice sheet started forming.

The massive east and west sheets that exist today began between 15 and 12 million years ago.   Warmer cycles have occurred since and it is not known how much of the ice retreated.   Fossil dolphins have been found kilometers inland that date around 4 million years.   Ancient tree fossils from 3 million years ago have been found in the Transantarctic Mountains.

As the glacial cycles became more extreme, the ice sheets advanced to cover almost the entire continent.   Eighteen thousand years ago, the ice sheet could have been as much as 100 to 500 meters thicker than it is at its present variation — between 2,000 to 4,000 meters, 1¼ mile to 2½ miles thick.

The West Antarctic ice sheet is much smaller and thinner, and has been classified, due to its base being below sea level, as a marine ice sheet.   The ice sheet sits on top of a mosaic of small blocks of continental crust and it is estimated that if all the ice melted — and the underlying crust rebounded to its normal position with the freeing of the tremendous ice weight — most of the area would remain covered by ocean water.   The West Antarctic sheet sits on crust in places 1½ miles below sea level.

One of the driest places on Earth

Precipitation on the continent averages 5 centimeters per year and Antarctica is classified as a desert.   Today, Antarctica, given its vast size, is the driest place on earth.

The Dry Valleys of Victoria Land, an island of rock surrounded by a sea of ice, exemplify this.   The McMurdo Dry Valleys are the largest ice-free area in Antarctica.   At times, the lakes have been as much as 400 meters deeper than they are now, likely fluctuating on a millennial timescale.

Some areas in the ‘dry’ valleys do have lakes and shallow water in this present time.   Some have so much salt they never freeze even when temperatures dip to -73°C.   The water at the more extreme temperatures becoming syrupy.

Other lakes work as a magnifying glass does.   Sun shining through the ice crust, heats the the bottom layers of cold, often turning the underneath water into a balmy +25°C.

In the dry valleys, those without any water, which are completely desolate, mummified seals are seen, but no live plant or animal life, nor even snow or ice. Patches of white are on the ground but this is not ice. The white deposits of salt, former lakes, the water long evaporated.

Her, however, under the vista of tall mountains and glaciers in the distance, beautifully shaped rock fragments called ventifacts stand among the red rock.

Some that might be called ornaments of an adorned garden.

Finger sized pyramids, to shapes large enough to crawl inside, the flat faces can meet in crisp angles, often the fine grained black basalt polished to a soft black luster.

In the peach, or the rose-hued evening sunlight, these shapes can resemble elephants, birds, even hollywood spaceships; anything you can take your fancy to imagine.

Carried from winds off the polar plateau, here among the polar desert full of buttes and canyons, sand action creates a salt weathering process called tafoni. Tafoni wears the stones into these polished sculptures.

As the wind whips around the edges of the stones, singing tones can be heard — eerie pitches that resonate through these monolithic structures.

In this ice-free land, as the wind howls, as the little moisture that enters evaporates into the atmosphere above, sand and wind continues nature’s creating urge.

Continues to make this one of the most fascinating spots on Earth.

The South Pole

The photo above was taken in the austral autumn of 1979.   Today a new Atmospheric Research Observatory has been built five hundred meters from the dome, (completed late 1996).   Other smaller buildings have been added.   A new South Pole Station main building is being seasonally constructed, expected to become operational the austral summer of 2005.   These buildings are generally downwind of the ARO (Clean Air Building).

1/3 of Antarctica has been designated as a ‘clean air sector’.   This designation means that no construction or travel is allowed inside this area by international treaty.   Ninety percent of the time the wind blows out of this area towards the Clean Air Building, allowing for careful precise measurements of various gasses.

Measurements show the steady global rise of CO₂       See picture of ARO and charts and explanation of taking measurements.

McMurdo Station, Ross Island, located on the McMurdo Sound, is the largest base on the continent.   With local time at Greenwich plus 12 hours, it serves as the control center and catchment area for “beakers,” or scientists traveling onto the continent.   Some coming to the South Pole station.

McMurdo, with medics, a decent meal, and a warm bed, has a sizable coffee house for the pilots and beakers, who come to study ice flow rates, and toxic gas emissions, and ozone depletion and even penguin fertility.   McMurdo is where, in austral summer time, there might be a 1,000 people passing through doing research.

The cold hits when setting foot at the geographical south pole.   Here wind-chill is the great equalizer on the polar plateau.   Wind chills of -73°C to -95°C are not uncommon.

December and January, the average temperature is around -28°C.

March through September the average temperature ranges between -54°C and    -60°C.

Every year there are some days when it drops below -73°C.

The warmest temperature in 43 years of recording is -13°C (+8°F).

All the buildings on the station are slowly migrating north about 10 meters, or 30 feet per year, as the ice underneath is moving.   Each January a new post is designated, showing the actual position of the geographical South Pole.

The vast polar plateau, the interior of the continent, is a mega-plateau, as high as some of the mountain peaks due to the thickness of ice.   This is where the station at the South Pole sits, at an elevation of 2,900 meters, almost 2 miles above sea level.   No landmarks are visible from the base.

With no trees or mountains, wind slips easily across the surface of the continent.   This air mass has an abrasive effect on the ground — grating and sculpting the snow and ice into strange, protruding designs.   These ice bumps — or waves of snow — are called ‘Sastrugis.’   Wonderful shapes can be made of this extremely fine ice crystal and snow that looks like shimmering, light dust.   The storms that build up these strange, packed snows can be a mind-numbing, white, milk-fog for those foolhardy enough to travel across the deserts.

1,000 meters above, air can be 30 degrees warmer than it is on the ground.   The skies are still clear but below winds of trapped layered air are producing Antarctic blizzards.   The higher warmer air is a part of what generates the katabatic winds that descend from the elevated plateau towards the coast.

New finding could have implications for sea level rises

French geographer, Philippe Buache in his Buache Map of 1739 shows two southern continents separated by an interior polar sea.   A peninsula juts northward of the smaller continent pointing towards Africa.   At the time no one in the present era had been to Antarctica and it is believed Buache copied his map from ancient Greek documents.   It is interesting to speculate that there was a period of history when the underwater Western Antarctic land portion was not totally covered in ice, and might not have been submerged.   At that time the Ross and Weddell seas could have been one sea between the two landmasses.   If this is so it is likely the map details came from as far back as Atlantis time, when the seas were lower — for those who choose to believe such an ancient civilization existed.

Our history shows that Captain James Cook was the first to cross the Antarctic Circle in his expedition of 1772-1775.   James Bransfield mapped the South Shetland Islands and part of the shore of the Antarctic Peninsula in 1820.   Fur sealing began and during that time it was held that the much of the ice shelves and sea ice were all part of the large landmass of Antarctica.   Only with the John Rymill expedition of 1934 was the curving land portion of the peninsula truly mapped.

Today the peninsula is seen as a land of mountains flanked by huge glaciers, deep fjords, ice shelves, sea ice and rugged offshore islands.   The widest, southern portion is Palmer Land and the offshore mountainous Alexander Island.   Palmer Land extends into Graham Land and Trinity Peninsula — a long, narrow spine of small peaks.   Many small islands are on the west side.   The South Shetlands and the Palmer Archipelago surround the tip.   The Antarctic coast is 670 miles, nearest point, from Cape Horn, South America.

A curving chain of submerged mountains continues under the ocean into the Scotia Sea.   These peaks surface in places as the South Orkneys, South Sandwich, and South Georgia islands.

The islands in this region have an astonishing diversity of Antarctic wildlife.   Penguin rookeries abound, and there are huge, elephant seal wallows along the shore.   Millions of birds, including giant and cape petrels, blue-eyed shags and kelp gulls, inhabit the shoreline.

The western coast is etched with fjords.   Among the dozens of islands are narrow passageways with towering rock faces and glaciers.   It is a spectacular maze of sheltered channels and inlets.   In the water, jet spouts can be seen being emitted from the blowholes of minke and humpback and orca whale as they exhale at the ocean’s surface.

Antarctica is uninhabited today — except for the research stations and scientific stations set up by various government.   But the islands off the peninsula have many reminders of early explorers, government bases and a whaling industry that once existed.

With spectacular surrounding mountains, glaciated peaks disappearing into the mist and clouds, this is the playground of the Antarctic for its animal inhabitants.

The past half-century has seen a dramatic increase in air temperature — one of the signs the Antarctic is giving us of a climate change.   The average summer temperature now approaches above freezing, and many small fringing ice shelves — such as the Wordie and Müller Ice Shelves on the western side of the peninsula — are retreating.   The larger Wilkins shelf on the southwest coast has stabilized after a dramatic summer breakup in 1998.

On the east side of the peninsula, the seaward front of the Larsen Ice Shelf began to retreat in the late 1940’s.   In 1995, almost 2,000 square kilometers of the northernmost ice disintegrated into hundreds of small icebergs during a storm.

The warmer temperatures allow melt water collecting in surface crevasses to penetrate to the bottom of the ice.   This aids in the dramatic displays seen in the ice-shelf disintegrations.   New large, shelf front rifts — and summertime surface melt ponds — are appearing in satellite images.   Many of the northern shelves continue to retreat.

Climate Change: Hundreds of Antarctic Glaciers In Retreat, Says Study

PARIS — Scientists have issued a fresh warning about the effect of climate change on Antarctica, saying that more than 200 coastal glaciers are in retreat because of higher temperatures.

Of the 244 marine glaciers that drain inland ice on the Antarctic peninsula, a region previously identified as vulnerable to global warming, 87 percent have fallen back over the last half century, according to research by British experts.

The shear face of the massive B-15A iceberg in McMurdo Sound after it broke off the Ross Ice Shelf in antarctica, November 2000.

Scientists say that more than 200 coastal glaciers in are in retreat because of higher temperatures.

Using 2,000 aerial photos dating back to the late 1940s and 100 satellite pictures, experts from the British Antarctic Survey (BAS) compiled a record of glacier-ice shelves and tidewater glaciers along the peninsula — the tongue of land that juts 800 kilometers (500 miles) northwards out of continental Antarctica.

Glacier-ice shelves are floating glaciers on the shoreline that are still connected to the land glaciers from which they flowed.

Tidewater glaciers rest on rock and break off into the ocean when they reach the water's edge.

Glacier fronts have reversed direction

Over the last half century, during which time regional temperatures have risen by around 2 C (3.6 F), these glacier fronts have reversed direction, the authors note in a study published on Friday in the US weekly journal Science.

Until the mid-1950s, most of the glaciers advanced. For the next decade after that, they were roughly stable. Since then, though, most have been shrinking.

In the past five years, the retreat has accelerated, and the pattern of retreat is widening. It started in the warmer northern tip of the peninsula and is heading progressively to the colder south as atmospheric temperatures rise.

"Fifty years ago, 62 percent of the glaciers that flowed down from the mountains to the sea we looked at were slowly growing in length, but since then this pattern has reversed," said lead author Alison Cook.

The average retreat of the 212 shrinking glaciers has been 600 metres (yards) over 50 years.

Numerous islands exposed that were once ice-smothered

But this does not take into account a dramatic acceleration in recent years, exposing numerous islands that were once ice-smothered.

Sjogren Glacier, at the northern tip of the peninsula has fallen back eight kilometers (8.5 miles) since 1993, while Widdowson Glacier, on the west coast of the peninsula, has been retreated at 1.1 kms (0.6 miles) per year over the past five year.

As for the cause, the BAS team caution against a leap to judgement.

At present, it is unclear that the man-made "greenhouse effect" — the burning of fossil fuels which disgorged carbon dioxide into the atmosphere, trapping solar heat — is entirely to blame, they say.

They note that over the past 50 years, a minority (32) of glaciers has grown, by an average of 300 metres (yards), and that key data on local ocean temperatures and circulation remain scarce.

Antarctica's geology is split into three main regions: East Antarctica, which comprises the bulk of the continent; West Antarctica, which has two huge ice shelves on either side; and the Antarctic Peninsula, which juts out of West Antarctica.

Peninsula hot spot for global warming

Previous research had already identified the peninsula as a vulnerable "hot spot" for global warming, although the reasons for this are debatable.

In February, BAS researcher Chris Rapley presented evidence that ice flows into the Southern Ocean from three big inland glaciers were accelerating, spurred by the loss of the vital shelves of floating glacial ice at the coast.

Like a cork released from a bottle, the lost shelves let the icy river flow swiftly into the sea, causing sea levels to rise by some 1.8 mm (0.07 inches) per year.

The new study repeats that warning, although without giving figures. It says the erosion of floating glacier ice could spur glacier flow from inland and "make a substantial contribution" to rising sea levels.

Antarctica, the fifth largest continent in the world, contains more than 90 percent of the world's ice, most of it above sea level.

If even a small part of this cap melts, rising sea levels could drown low-lying island states, cities and deltas.

Published on Friday, April 22, 2005 by the Agence France Presse

Continue with Antarctic — Load Master file

The WE Environment News Archives

South Pole Observatory, Antarctica

          CO2 record high levels in the atmosphere
           — Climate fear as carbon levels soar
      Highest for 650,000 years

(See Abrupt Climate Change and Global Warming in Kalaallit Nunaat section
   includes Pentagon report on abrupt climate change)

(See Recent changes observed in Arctic Areas - in Arctic section.)

Mount Everest and climate change

Antarctica here we come

Antarctica here we come 2003 version

Sailing through the antarctic Peninsula

Wilkes land

A look at the flat South Pole - Base 90º South.