Heavy masses of ice push down on bedrock, depressing areas in the central part of the ice sheet below mean sea level. If those low-lying areas happen to be near the edge of the ice sheet, which is the case in large parts of West Antarctica, then ocean water can make its way under the ice, speeding up glacier flow. This is one of the reasons that while both portions of the ice sheet are losing mass, West Antarctica is moving much faster.
Recent studies of West Antarctica found that many of the large, fast-moving glaciers there are in an irreversible decline. And while Antarctic land ice is shrinking, sea ice around the continent has been on the rise in recent years. Antarctica is surrounded on all sides by the Southern Ocean.
During the winter, ocean water freezes, forming a layer of sea ice of roughly the same area as the Antarctic continent. The ocean around Antarctica is divided into several seas. Residents live mostly on frozen and canned food.
The chef is often thought of as one of the most important people at Davis Station. He or she must make sure to use all commodities in such a way that is both creative and sustainable.
Hydroponics is the practice of growing plants with water and nutrient s only. Hydroponics requires excellent gardener s because produce is grown without soil. Fresh produce adds variety and nutrition to Antarctic meals. The greenhouse also serves as a sunroom for sunlight-deprived residents, especially during the long winter months. By the early 20th century, explorers started to traverse the interior of Antarctica. The aim of these expeditions was often more competitive than scientific.
In , Amundsen, of Norway, and Scott, of the United Kingdom , began expeditions with the aim of becoming the first man to reach the South Pole. Each team used different methods, with drastic ally different levels of success. The team was healthy, and successfully made the journey out of Antarctica.
They all died on their journey home. Hoping to one-up his predecessors, Shackleton, of the United Kingdom, attempted the first transcontinental crossing of Antarctica in Shackleton planned the trip by using two ships, the Aurora and the Endurance , at opposite ends of the continent. Aurora would sail to the Ross Sea and deposit supplies. On the opposite side, Endurance would sail through the Weddell Sea to reach the continent. Once there, the team would march to the pole with dog teams, dispose of extra baggage, and use supplies left by Aurora to reach the other end of the continent.
The plan failed. The Endurance became frozen in the pack ice of the Weddell Sea. The pack ice crushed and sunk the ship. Their food sources were leopard seals, fish, and, ultimately, their sled dogs. Although some of the crew sustained injuries, they all survived. The journey of the Endurance expedition symbolizes the Heroic Age, a time of extreme sacrifice and bravery in the name of exploration and discovery.
Apsley George Benet Cherry-Garrard, a polar explorer, summed up the Heroic Age in his book The Worst Journey in the World : "For a joint scientific and geographical piece of organisation, give me Scott; for a Winter Journey, Wilson; for a dash to the Pole and nothing else, Amundsen: and if I am in the devil of a hole and want to get out of it, give me Shackleton every time.
This change was initially fueled by the Cold War , a period of time defined by the division between the United States and the Soviet Union , and the threat of nuclear war. The International Geophysical Year IGY of aimed to end Cold War divisions among the scientific community by promoting global scientific exchange.
The IGY prompted an intense period of scientific research in the Antarctic. Many countries conducted their first Antarctic explorations and constructed the first research stations on Antarctica. Under the treaty, the size of these claims cannot be changed and new claims cannot be made.
Most importantly, the treaty establishes that any treaty-state has free access to the whole region. As such, research stations supported by a variety of treaty-states have been constructed within each of these territorial claims. Today, 47 states have signed the Antarctic Treaty. The Antarctic Treaty was an important geopolitical milestone because it was the first arms control agreement established during the Cold War.
Along with the IGY, the Antarctic Treaty symbolized global understanding and exchange during a period of intense division and secrecy. Many important documents have been added to the Antarctic Treaty.
Collectively known as the Antarctic Treaty System, they cover such topics as pollution , conservation of animals and other marine life, and protection of natural resource s. Only 28 of the 47 treaty-states have decision-making powers during these meetings. These include the 12 original signatories of the Antarctic Treaty, along with 16 other countries that have conducted substantial and consistent scientific research there.
Future Issues Two important and related issues that concern the Antarctic region are climate change and tourism. The ATCM continues to address both issues. Antarctic tourism has grown substantially in the last decade, with roughly 40, visitors coming to the region in Officials worked closely with the International Association of Antarctica Tour Operators IAATO to establish better practices that would reduce the carbon footprint and environmental impact of tour ships.
These include regulations and restrictions on: numbers of people ashore; planned activities; wildlife watching; pre- and post-visit activity reporting; passenger, crew, and staff briefings; and emergency medical-evacuation plans.
Climate change disproportionately affects the Antarctic region, as evidenced by reductions in the size of the Antarctic Ice Sheet and the warming waters off the coast. The ACTM recommended that treaty-states develop energy-efficient practices that reduce the carbon footprint of activities in Antarctica and cut fossil fuel use from research stations, vessels, ground transportation, and aircraft.
The Antarctic has become a symbol of climate change. Scientists and policymakers are focusing on changes in this environmentally sensitive region to push for its protection and the sustainable use of its scientific resources. Not until was it established that Antarctica was a continent and not just a group of islands. Also called an alpha predator or top predator.
The two sides never confronted each other directly. The Earth is the only place in the known universe that supports life. Also called East Antarctica. Also called the energy balance. Also called West Antarctica. National Aeronautics and Space Administration the U. Also called thermohaline circulation. Sea level is determined by measurements taken over a year cycle. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
The Rights Holder for media is the person or group credited. Caryl-Sue, National Geographic Society. Dunn, Margery G. For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format.
When you reach out to them, you will need the page title, URL, and the date you accessed the resource. If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.
Text on this page is printable and can be used according to our Terms of Service. Then there is a flash in the shallows by my feet - an arrow of white and black. What on earth fish is that? My slow brain ponders, as before my eyes a gentoo penguin slips out of the water, steadies itself on a rock, eyes me cheekily, squawks and patters off into the snow. Antarctica is the hardest place I know to write about.
Whenever you try to pin down the experience of being there, words dissolve under your fingers. There are no points of reference. In the most literal sense, Antarctica is inhuman. Other deserts, from Arabia to Arizona, are peopled: humans live in or around them, find sustenance in them, shape them with their imagination and their ingenuity.
No people shape Antarctica. It is the driest, coldest, windiest place in the world. So why, then, have Britain, France, Norway, Australia, New Zealand, Chile and Argentina drawn lines on Antarctica's map, carving up the empty ice with territorial claims? Antarctica is not a country: it has no government and no indigenous population. Instead, the entire continent is set aside as a scientific preserve. The Antarctic Treaty , which came into force in , enshrines an ideal of intellectual exchange.
Military activity is banned, as is prospecting for minerals. Fifty states - including Russia, China and the US - have now ratified the treaty and its associated agreements. Yet one legacy of earlier imperial expeditions, when Shackleton and the rest battled blizzards to plant their flags, is national covetousness. Science drives human investigation in Antarctica today, yet there's a reason why geologists often take centre-stage.
Governments really want to know what's under the ice.
0コメント