Mertz glacier
| Mertz glacier | ||
|---|---|---|
 The huge Mertz glacier |
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| location | George V coast , Antarctica | |
| length | 160 km before the 2010 collision | |
| width | Max. 40 km | |
| Coordinates | 67 ° 30 ′ S , 144 ° 45 ′ E | |
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| drainage | Lake D'Urville | |
The Mertz Glacier is a glacier protruding into the ocean on the Antarctic continent . It is located in the Victoria Land area, claimed by Australia , directly on the southern ocean . In February 2010 it was rammed by a gigantic iceberg in a rare "collision of the century" and broke in two.
Naming
In December 1911, the Australasian Antarctic Expedition began under the leadership of the Australian geologist Douglas Mawson . The aim of the expedition was initially to map the approximately 2000 kilometers long coastal strip facing the Australian continent. The expedition also served to explore and research previously unknown terrain, and the first meteorite Adelie Land to be found in Antarctica also came from this expedition. Information about Adelie Land ( Memento of September 28, 2007 in the Internet Archive )
In November 1912, three polar explorers - the Australian Mawson, the Swiss Xavier Mertz and the British Belgrave Ninnis - began a multi-week exploration of King George V Land by dog sledding. On December 14, 1912, Ninnis fell into a crevasse and with him six dogs and most of the food. Mawson and Mertz then broke off the exploration and tried to return to the base camp , which is more than 500 kilometers away . The first glacier they crossed on the way back they called the Ninnis Glacier. Since the two researchers had run out of food, they had to gradually butcher and eat the sled dogs on their way back to survive. From January 1, 1913, Mertz complained of stomach ache and was unable to continue on his own. From then on, Mawson had to transport him by sledge. Mertz fell into delirium 150 kilometers from the base camp and died on January 7, 1913. Mawson named the next glacier crossed after the deceased Mertz. Mawson himself reached base camp on February 8, 1913.
Initially, it was believed that Mertz was poisoned with vitamin A (hypervitaminosis A), which was caused by eating dog liver. According to more recent studies, however, it is now assumed that the researcher, who had previously lived strictly as a vegetarian and was under intense psychological stress in an emergency, could not tolerate the switch to now completely carnal food.
glaciology
Glaciers are huge ice masses that are on land or snow and move independently due to the slope, the structure of the ice, the temperature and the shear stress resulting from the mass of the ice . Ice masses floating in the water are not glaciers, but icebergs . Like icebergs, glaciers consist of fresh water.
The Mertz Glacier is located in eastern Antarctica, in quadrant C. It is around 3,100 kilometers from the Australian mainland coast and around 2,500 kilometers from New Zealand. The extension of the Mertz Glacier was around 160 kilometers in length in north-south direction and around 35 to 40 kilometers in width in east-west direction. More than half of it protruded into the open sea as a peninsula-like tongue . The height of the glacier is around 400 meters; it flows into the sea at a speed of one kilometer per year and transports ten to twelve billion tons of ice into the ocean every year. The glacier tongue took around 70 years to form to its size. A transverse crack about 25 kilometers long was discovered 20 years ago. This crevasse was around 50 to 100 meters wide. A second crevasse was formed in 2002. Through these two cracks, the part of the glacier protruding into the ocean was already loosened; both cracks had recently almost joined.
collision
collision
One of the largest icebergs in Antarctica, the 95-kilometer-long B-9B , broke off the Ross Ice Shelf in 1987 and had been stranded around 100 kilometers east of the Mertz Glacier since 1992. After it broke loose in February 2010, it drifted towards the glacier. On February 12 or 13, 2010, the iceberg then rammed the tongue of the glacier protruding into the sea. The glacier then broke into two large parts. The solid part is still on land, while the broken part of the glacier, around 78 kilometers long and 39 kilometers wide, is now forming a new iceberg. With 2500 square kilometers, it is the size of Luxembourg and weighs around 700 billion tons. Both the older iceberg B-9B and the recently formed iceberg are now drifting about 100 to 150 kilometers apart off the Antarctic coast. Such collisions happen very rarely, they only happen every 50 to 100 years. Therefore, the ice carom is also known as the "collision of the century".
Surname
At first the new iceberg was unofficially referred to as the Mertz Iceberg by Australian Antarctic researchers . But it was then named C-28 . The National Ice Center in Maryland, USA has been giving the name to icebergs that are larger than ten nautical miles, or around 19 kilometers, and that move in a certain proximity to Antarctica since 1976. The letter C is based on one of the four quadrants into which Antarctica is divided and from which the iceberg originates. The C-28 is the 28th iceberg to have formed in quadrant C since 1976.
Effects
If the two huge icebergs had withdrawn northwards towards Australia, their influence would be small. However, the two ice colossi remained near the Antarctic and drifted into a previously ice-free zone . These ice-free zones play a major role in the formation of very cold and salty water, which sinks into the depths due to its density and weight. This creates an upheaval of gigantic water masses. This in turn influences the global climate and weather by the fact that the Antarctic regulates the water temperature and supplies the oceans with cold, oxygenated water. About 20 to 25 percent of this cold Antarctic deep water originates in the region around the Mertz Glacier and is transported from there by the currents. A disruption of the previous natural process due to a blockage of the ice-free zone by the Mertz iceberg could lead to less cold water entering the global circulation. The global ocean currents would slow down. According to some glaciologists and climate scientists, this has two major consequences: First, there could be warmer winters in the North Atlantic, which in turn would have consequences for the northern continents. Second, the oxygen content in the deeper ocean currents could decrease or be lost, which would lead to the death of life in these regions. Other climate scientists, however, consider the collision to be a natural process that has no significant climatic effects on the northern hemisphere.
Individual evidence
- ↑ Welt Online, article Crash of the Century at the South Pole from February 26, 2010
- ^ The Medical Journal of Australia, Article Mawson and Mertz: A Re-evaluation of Their Ill-fated Mapping Journey During the 1911–1914 Australasian Antarctic Expedition April 2005
- ↑ Spiegel Online, article In the End They Ate Sled Dogs, March 11, 2008
- ↑ Swisseduc.ch, Glaciers online
- ^ Agence France-Presse Iceberg the size of Luxembourg in Antarctica, canceled on February 26, 2010
- ↑ press release austria, article Giant Iceberg Could Disrupt World Weather from February 26, 2010
- ↑ FAZ.net, article Giant glacier tongue broken off - It made cracks from February 26, 2010
- ^ Spiegel Online, article Gigantic Iceberg in Antarctica, canceled on February 26, 2010
- ↑ stern.de, article Century collision in the Antarctic - ice giant breaks off the glacier from February 26, 2010
- ↑ DW - World.de Deutsche Welle, article Eiskarambolage in der Antarctica from February 26, 2010
- ^ ESA Germany, local news from March 5, 2010
- ↑ Focus Online, article New giant iceberg puts oxygen in the world's oceans at risk from February 26, 2010
- ↑ Welt Online, article New Iceberg after the Collision of the Century ( Memento from February 27, 2010 in the Internet Archive ) from February 26, 2010
- ↑ Press Releases-online.de, Article Giant iceberg of 2,500 square kilometers discovered in the open sea on February 26, 2010
- ↑ Der Tagesspiegel, article Frosty Clash from March 1, 2010
