Plate Tectonics

Which layer of the Earth contains the asthenosphere?

• crust

• mantle

• inner core

• outer core

When two tectonic plates collide, the oceanic crust usually subducts beneath the continental crust because it is

• denser than the continental crust

• less dense than the continental crust

• thicker than the continental crust

• thinner than the continental crust

If you will visit a place in the Pacific known to be along converging plates, which of these should you not expect to see?

• active volcanoes

• mountain ranges

• rift valleys

• volcanic island

All are primary plates EXCEPT

• Antarctic Plate

• Eurasian Plate

• Pacific Plate

• Philippine Plate

Using the” triangulation” technique, seismologists can obtain the distances from at least three seismographic stations, plot the values, and find their common intersection, which is the ___________.

The theory of moving lithospheric plates is called ______________.

The lithospheric plates are believed to be moving slowly. What is the driving force that facilitates this movement?

• Convection current in the mantle

• Force of the atmosphere

• Gravitational force of the moon

• Magnetic forces at the poles

If the Atlantic Ocean is widening at a rate of 3cm per year, how far (in km) will it spread in a million years?

The magnitude of an earthquake can be measured on the _________________ scale.

Volcanoes are classified as active, ________________ or extinct depending on their eruption history.