Not only has the extent of the sea ice changed, but so has the character. Arctic sea ice has become much younger. As NOAA explains, when it comes to ice, age refers to thickness and durability. Young gel it is thinner and more likely to melt in the summer. The oldest ice, which is usually four years old or older, is an ice that survives throughout the year and thickens over time. By National Snow and Ice Data Center, the old ice can be between six and 25 feet (1.8 to 7.6 meters) thick.
As you can see in the chart, the oldest Arctic ice is a bit of what it was before. In 1985, 33% of Arctic ice was very old ice; as of March 2020, only 4.4% of sea ice was old.
Seconds NOAA20 to 30 years ago, sea ice in the Arctic was dominated by old sea ice. Over time, however, the old ice came out of the Arctic through the Fram Strait, where it melted into the relatively warmer waters of the Atlantic. This was not a problem then, as new batches of old ice were created in the Beaufort Gyre, which NOAA describes as a “nursery” for young ice to become thicker and stronger as it moves for many years. . Today, summers on the southern branch of the Beaufort tour are often too hot for the ice to survive, the agency said.
Use a sentence from the file NSIDC, this “Benjamin Button Ice” is an element in a dangerous cycle, in which rising air and ocean temperatures more easily destroy first-year ice and weaken older ice. If this cycle continues and the oldest ice disappears from the Arctic Ocean, the world may see ice-free summers in the Arctic as early as 2030.