Dynamic Crust Review Sheet

Front

Which Earth layer is inferred to be composed of solid nickel and iron?

Back

D

Front

Compared to oceanic crust, continental crust is generally

Back

older and thicker

Front

According to the plate tectonics theory, the Peru-Chile Trench and the Andes Mountains formed along the west coast of South America because the South American Plate...

Back

collided with the Nazca Plate

Front

When two tectonic plates collide, oceanic crust usually subducts beneath continental crust because oceanic crust is primarily composed of igneous rock that has

Back

high density and is mafic

Front

The cross-section shows the direction of movement of an oceanic plate over a mantle hot spot, resulting in the formation of a chain of volcanoes labeled A, B, C, and D. The geologic age of volcano C is shown. What are the most likely geologic ages of volcanoes B and D?

Back

B is 5 million years old and D is 12 million years old

Front

The movement of tectonic plates is inferred by many scientists to be driven by: tidal motions in the hydrosphere, density differences in the troposphere, convection currents in the asthenosphere, solidification in the lithosphere

Back

convection currents in the asthenosphere

Front

Which features are commonly formed at the plate boundaries where continental crust converges with oceanic crust? Options: large volcanic mountain ranges parallel to the coast at the center of the continents, A deep ocean trench and a continental volcanic mountain range near the coast, An underwater volcanic mountain range and rift valley on the ocean ridge near the coast, Long chains of mid-ocean volcanic islands perpendicular to the coast

Back

A deep ocean trench and a continental volcanic mountain range near the coast

Front

The map to the right shows the continents of Africa and South America, the ocean between them, and the ocean ridge and transform faults. Locations A and D are on the continents. Locations B and C are on the ocean floor. The oldest basaltic crust is most likely located at point

Back

B

Front

A seismic station is located 8000 kilometers from the epicenter of an earthquake. How long did it take the first P-wave to travel from the epicenter to the seismic station?

Back

11 minutes 20 seconds

Front

A seismograph records the arrival of a P-wave at 11:13 am. If the earthquake occurred 4000 kilometers from the recording station, when did the earthquake occur?

Back

11:06 am