Apart from global warming being a major cause for this loss, wind currents have also played a key role by blowing sea ice south into the Atlantic Ocean, where the ice then melted. This phenomenon has led scientists to envision a grim future for the Arctic's so-called perennial sea ice, which is the ice that survives through the summer.
"If this trend persists, the Arctic would be ice-free in the summer by 2013," National Geographic News quoted Wieslaw Maslowski of the Naval Postgraduate School in Monterey, California, as saying.
The Arctic's perennial sea ice has been shrinking since the 1980s. Before then, ice filled the whole Arctic Ocean throughout the summer, occupying an area the size of the continental United States.
But the melt this year brought it to a new low in September, melting an area larger than all of the US states east of the Mississippi River.
The new record blew the old record, set in 2005, shrinking to just three-quarters the size of that earlier low.
According to Jim Maslanik of the National Snow and Ice Data Center in Boulder, Colorado, "The ice that remains is also newer ice, which is typically not as strong as ice that's been compacted over several years."