1001 Space Earth Earth Rocks and Minerals Landscape Sea Weather and Climate Natural Disasters Resources Nature History Human World Science and Technology

Choose a Page:How long has there been life in th...How much of the Earth is covered b...Why does seawater taste salty?*Is the ocean floor flat?*What causes waves?What is an iceberg?Are tidal waves caused by the tides?What are ocean currents?How has the ocean bed been measured?How does the sea affect the climate?How do coral reefs form?Are there currents at great depths?Why does the tide come in and go out? Is the ocean floor flat? The floor of the ocean has a very varied topography. A series of volcanic ridges cuts through all the oceans. These ridges mark the sites where the Earth's surface plates are being created. Deep ocean troughs occur in places where one of the Earth's plates is being pulled down beneath another and destroyed. Volcanoes that rise up from the ocean floor produce chains and arcs of islands. Landscape features on the ocean floor include mountains taller than Mount Everest, 6 miles(10 km) deep trenches, valleys, ridges, and volcanoes.   Previous: Back Book: 1001 Section: Earth Chapter: Sea