Antarctica's sea ice drops to an 'alarming low' for the third year in a row, scientists warn


Here we go again: The ice loss is almost entirely in Western Antarctica, which is known for subsurface vulcanism. And volcanic eruptions are unpredictable, which is what they found. Nothing to do with global warming

Antarctica's sea ice has dropped to an 'alarming' low during the southern hemisphere's summer, scientists have revealed.

Ice surrounding Earth's southernmost continent now measures less than 772,200 square miles (2 million sq km), or about the size of Mexico.

Worryingly, this is the third year in the row that this figure has fallen below this threshold, according to the US National Snow and Ice Data Center (NSIDC).

Less sea ice can threaten habitats for penguins, seals and other Antarctic animal life, and also contributes to a rise in global sea levels.

Unfortunately, it follows a record-breaking low for Antarctica's sea ice during the winter as well.

What is sea ice?

Sea ice is simply frozen ocean water. It forms, grows, and melts in the ocean. It floats on the surface of the sea because it is less dense than liquid water. In contrast, icebergs, glaciers, ice sheets, and ice shelves all originate on land.

Sea ice is estimated to cover around 7 per cent of Earth's surface and about 12 per cent of the world's oceans.

The lion's share of sea ice is contained within the polar ice packs in the Arctic and Southern oceans.

These ice packs undergo season variations and are also affected locally on smaller time scales by wind, current and temperature fluctuations.

Walt Meier, a senior research scientist at NSIDC, said experts 'don’t yet know the full reason' why sea ice is now at a record low, although 'global warming certainly could be a factor'.

'It appears that warm ocean temperatures are important, but other factors may be in play, including wind patterns,' he told MailOnline. 'We have only 45 years of high quality data, which still may not capture all of the variability in the Antarctic sea ice.

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