The national border between Italy and its adjacent countries traverses high altitudes on snowfields and perennial ice sheets, mostly following the path of the main Alpine watershed.
Due to global warming and shrinking Alpine glaciers, a considerable shift of the glacial watershed has been detected—and accordingly of the coinciding national borders. A new concept of movable border has thus been introduced by the Italian Government into national legislation.
In order to track the movement of the Austrian-Italian movable border, a grid of 25 solar-powered sensors have been installed on the surface of the glacier at the foot of Mt. Similaun. Once every two hours, they record data, allowing for automated mapping of the shifts in the border.