By DPA
Washington : Despite an unusually cold winter in the Arctic, the oldest and thickest sea ice there continues to shrink, NASA officials said Tuesday while releasing the latest satellite images of the area.
The colder-than-average winter lead to an overall increase in new sea ice, but global warming has caused the amount of so-called perennial ice to shrink to about 30 percent of the total ice pack from about 40 percent last year, the National Snow and Ice Data Center said.
The year-round ice, which remains after ice formed in the winter melts in the warmer months and last for several years, has historically made up 50 to 60 percent of all Arctic ice, but has become more vulnerable, melting and moving out of the Arctic, scientists said.
The oldest ice, which lasts for at least six years, made up just six percent of the total, down from more than 20 percent in the 1980s.