Across
- 2. occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust.
- 3. about 2,200 kilometers (1,367 miles) thick, is mostly composed of liquid iron and nickel.
- 7. is what happens when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault or fault plane.
- 8. enormous sections of Earth’s crust that roughly fit together and meet at places
- 11. the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.
- 12. are where Earth's tectonic plates dive back into the mantle, at rates of a few to several centimeters per year. These are key features of Earth's plate tectonic regime. An oceanic trench shows where the plate disappears, and a dipping zone of earthquakes show where the subducting plate is.
Down
- 1. Two plates sliding past each other forms a
- 4. the rigid outer part of the earth, consisting of the crust and upper mantle.
- 5. is a fracture or zone of fractures between two blocks of rock.
- 6. is the layer of granitic, sedimentary, and metamorphic rocks, which form the continents and the areas of shallow seabed close to their shores
- 9. is a layer inside a planetary body bounded below by a core and above by a crust.
- 10. Volcanic rock (or lava) that characteristically is dark in color (gray to black), contains 45 to 53 percent silica, and is rich in iron and magnesium.
- 13. a hot, dense ball of (mostly) iron. It has a radius of about 1,220 kilometers (758 miles).