| A | B |
|---|
| sphere | a round three-dimensional object, like a globe |
| biosphere | the area on earth with living organisms |
| atmosphere | the gaseous part of earth |
| hydrosphere | the watery part of earth |
| theory | an explanatory model, supported by evidence |
| continental shelf | a part of the coastal plain that extends underneath the ocean |
| create | to make or form |
| external | outside |
| core | area at the center |
| mantle | the region of the earth's interior between the crust and the core |
| continental drift | the gradual movement of the continents across the earth's surface through geological time. |
| plate tectonics | the theory that Earth's outer shell is divided into several plates that glide over the mantle |
| magma | hot fluid or semifluid material below or within the earth's crust |
| subduction | the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate. |
| desalination | the process of removing salt from seawater |
| water cycle | the rotation of water from ocean to air and back to the ocean |
| erosion | the movement of weathered rock by wind, glaciers, and moving water |
| plate tectonics | creates many of earth's physical features through continental drift and magma flow |
| subduction | oceanic plates dive under continental plates, sometimes causing magma to rise and form volcanic mountains on land |
| accretion | oceanic plates slide under continental plates and scrape off seamounts leaving debris that causes continents to grow outward |
