| A | B |
|---|
| geology | the study of earth's physical structure and history |
| crust | the rocky surface layer, very thin |
| percent of water on earth | more than 70% |
| island | a peice of land surounded by water |
| isthmus | narrow strip of land that joins two bodies of land, which have water on both sides of it |
| delta | a deposit of sand and oil formed at the mouth of some rivers. |
| lake | an inland body of water |
| magma | molten rock underneath the earth |
| faults | a break in the earth's crust |
| continental drift theory | the idea that continents slowly shift there positions, by riding on tectonic plates. |
| convection | when warm air rises and cool air falls |
| converging | being directed in the same direction |
| core | the very center of the erath which contains hot metal |
| continent | a large mass in the ocean |
| 4 major types of landforms | mountains, oceans, volcano, plain, etc. |
| archipelago | a sea with many islands |
| peninsula | a land area almost entirley surounded by water |
| gulf | a large area of ocean, reaching into land |
| butte | a steap hill standing alone in a plain |
| lava | molten rock |
| plate tectonics | a group of eight plates moving around under the ocean floor |
| Seafloor Spreading | the landforms on the ocean floor |
| spreading | when two plates move apart from one another and cause magma to rise and make new land |
| faulting | break in the earth's crust |
| mantle | thick layer of rock that surrounds earth's core |
| relief | the differense in elevation between the highest and lowest point |
| straight | a river without having curves |
| volcano | formed when magma, breaks through earth's crust |
| sound | a deep body of water |
| canyon | a long narrow valley between cliffs |
| volcanism | movement of magma inside the earth |
| fold | when rock layers bend and buckle |
| Pangea | a theory of how the world was before it was broken |
| Rift Valley | a valley with a huge opening in it. |
| subduction | to pull down |
| Rind f Fire | circle of volcanoes surounding the pacific ocean |
