Waterfalls
Angel Falls in Venezuela is the world's tallest waterfall at 979 m (3,212 ft ). A waterfall is an area where water flows over a vertical drop or a series of steep drops in the course of a stream or river . Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf . Waterfalls are commonly formed in the upper course of a river in steep mountains. Because of their landscape position, many waterfalls occur over bedrock fed by little contributing area, so may be ephemeral and flow only during rainstorms or significant snowmelt. The further downstream, the more perennial a waterfall can be. Waterfalls can have a wide range of widths and depths. Aerial view of Iguazu Falls on the Iguazu River between Brazil and Argentina When the river courses over resistant bedrock, erosion happens slowly and is dominated by impacts of water-borne sediment on the ro...