Ice can be a powerful force, it can split rock apart, and shape valleys and mountains. Ice causes these changes slowly and over a longer period of time. Ice can also wear away or dissolve rock. Melted ice under a glacier can move rock from one place to another. In these ways, ice causes changes to earth's surface. Changes to glaciers caused by warming temperatures can be harmful to people's lives. Melting glaciers can cause flooding in some places and lead to water shortages in other places.