Earth's Surface: Land Versus Water 3) The continental shelf steepens slightly at 100 200 meters below sea level The continental slope is the flooded continental margIn a The continental rise descends more gently from the base of the continental slope. Earthquakes and volcanoes are common along active margins
Earth’s Surface: Land Versus Water (3) ◼ The continental shelf steepens slightly at 100- 200 meters below sea level. ◼ The continental slope is the flooded continental margin. ◼ The continental rise descends more gently from the base of the continental slope. ◼ Earthquakes and volcanoes are common along active margins
Continental shelf Continental slope Shoreline Continental rise Midocean ridge Sea level B Abyssal plain Central rift valley Oceanic crust 500100015002000km Continental Geological edge crust of continent Topography of the Seafloor
Topography of the Seafloor
Earth's Surface: Land versus Water(4) Ocean trenches occurs where oceanic lithosphere and continental lithosphere converge at the boundary between two plates. Because oceanic lithosphere is the denser of the two. it descends under the active continental margin and sinks into the deeper mantle. The large, flat abyssal floors of the open ocean lie 3 to 6 km below sea level
Earth’s Surface: Land Versus Water (4) ◼ Ocean trenches occurs where oceanic lithosphere and continental lithosphere converge at the boundary between two plates. ◼ Because oceanic lithosphere is the denser of the two, it descends under the active continental margin and sinks into the deeper mantle. ◼ The large, flat abyssal floors of the open ocean lie 3 to 6 km below sea level
What earth's internal phenomena tell us Rocks are poor conductors of heat, so Earth moves its internal heat by moving the rock itself. a The circulation of hot rock is maintained by mantle convection
What Earth’s Internal Phenomena Tell Us ◼ Rocks are poor conductors of heat, so Earth moves its internal heat by moving the rock itself. ◼ The circulation of hot rock is maintained by mantle convection
Ocean Continent floor Ocean Continent Wa later co cools cools water Hot water water Cold sInks rock sink Cold rock sinks Hot rock Convection in the mantle
Convection in the Mantle