Volcanic activity created the island of Iceland and volcanoes still dominate its landscape. The country has more than 30 active volcanic systems, and plenty of researchers who are investigating them.One of the scientists is Sigrún Hreinsdóttir, a geophysicist at the University of Iceland. By using sensors equipped with GPS, she monitors how the surface of a volcano moves before an eruption. The aim is to develop an early warning system that would alert people who live nearby when a volcano is about to blow.