 Only about 1% of Antarctic ice area can be considered to be blue-ice area, but they have attracted scientific interest due to the large numbers of meteorites that accumulate on them; these meteorites either fall directly on the blue-ice area and remain there or they fall elsewhere into the ice sheet and are transported to the blue-ice area by ice flow.Additionally, ice up to 2.7 million years old has been obtained from blue-ice areas.Blue-ice areas are sometimes used as runways for aircraft.