Satellite images taken more than three decades apart show the disappearance of Iceland's Okjökull, the first glacier to be ...

Hawaii's Mauna Loa and Kilauea are both shield volcanoes. Though they don't form a classic cone shape, shield volcanoes can be massive: Mauna Loa has an estimated volume of 18,000 cubic miles ...

another highland region and massive shield volcano, respectively. Either way, Nerio's significant mass altered the shape of Mars with its gravity, raising tides in the magma oceans the same way ...