Reasons for increase in ice cover surrounding Antarctica

A new NASA-led study has found the geology of Antarctica and the Southern Ocean is responsible. They found that two persistent geological factors the topography of Antarctica and the depth of the ocean surrounding it are influencing winds and ocean currents, respectively, to drive the formation and evolution of Antarctica’s sea ice cover and help sustain it. The behaviour of Antarctic sea ice is entirely consistent with the geophysical characteristics found in the southern polar region, which differ sharply from those present in the Arctic. Their analyses revealed that as sea ice forms and builds up early in the sea ice growth season, it gets pushed offshore and northward by winds, forming a protective shield of older, thicker ice that circulates around the continent. The persistent winds, which flow down slope off the continent and are shaped by Antarctica’s topography, pile ice up against the massive ice shield, enhancing its thickness. This band of ice, which varies in width from roughly 100 to 1,000 km, encapsulates and protects younger, thinner ice in the ice pack behind it from being reduced by winds and waves.
As the sea ice cover expands and ice drifts away from the continent, areas of open water form behind it on the sea surface, creating “ice factories” conducive to rapid sea ice growth

Implications of ice loss in Arctic:

• Loss of ice means more heat is absorbed.
• The less sunlight is reflected, the more heat the planet absorbs.
• The heat doesn’t only warm the oceans. Heat entering the oceans during summer is later released back into the atmosphere raising atmospheric temperatures too. It’s one important reason why the Arctic is warming faster than the rest of the planet.

Geopolitical implications

• Territorial disputes: In 2008, the five littoral Arctic nations reaffirmed their commitment to the law of the sea in the Arctic with the Ilulissat Declaration, but a few sovereignty disputes persist. However, the 5 countries located along the shore of the Arctic Ocean – Russia, the US, Denmark, Canada and Norway– have competing territorial claims.
• For example, the United States and other nations assert that the Northwest Passage is an international strait with free navigation rights, while Canada says it’s an inland waterway over which it maintains exclusive jurisdiction. Washington and Ottawa also disagree on their maritime boundary in the resource-rich Beaufort Sea.
• Several states have also made competing claims on the Lomonosov Ridge, an undersea mountain range bisecting the Arctic Ocean.

Energy reserves:

U.S. Geological Survey (USGS), estimated that nearly one-quarter of the earth’s undiscovered, recoverable petroleum resources lie in the region: 13 percent of the oil; 30 percent of the natural gas; and 20 percent of the liquefied natural gas. More than 80 percent of these are thought to be offshore. The Northern Sea Route along Russia’s edge, that is likely to be free of ice first, can reduce the sailing distance between Asian ports and northern Europe by 40 per cent. The other major Arctic shipping route is the Northwest Passage, which connects Europe and Asia. It is nearly 5,000 nautical miles shorter than the 12,600 nautical mile distance between Europe and Asia through the Panama Canal.