 They originally fell on ice elsewhere and were transported by ice flows to the blue-ice area, where they accumulate when the ice they were encased in ablates away; this mechanism has been compared to a conveyor belt that transports meteorites to blue-ice areas.Additionally, meteorites that fell directly on the blue-ice areas are represented; because of the often great age of the surface a number of meteorites can accumulate even without ice-driven transport.Over 20,000 meteorites from blue-ice areas were known by 1999, a large share of all known meteorites on Earth.