An extensive cold wave that has swept across northern China over the last few days has seen the total sea ice area expand rapidly, with the huge ice blocks now blanketing an area spanning almost 13,000 square kilometers. The outer boundary line of the ice area has expanded out to 56 nautical miles, with more than 42 percent of the bay's sea surface covered by floating ice blocks. With a coastline stretching over 1,200 km, the Liaodong Bay is the largest and longest of the three main bays of the Bohai Sea, which cover the innermost gulf of China's Yellow Sea. It is typically covered in thick ice throughout winter until early spring.