Plate Tectonics

Compared to the average density and composition of oceanic crust, continental crust is

• less dense and more felsic

• less dense and more mafic

• more dense and more felsic

• more dense and more mafic

What are the inferred pressure and temperature at the boundary of Earth's stiffer mantle and outer core?

• 1.5 million atmospheres pressure and an interior temperature of 4950°C

• 1.5 million atmospheres pressure and an interior temperature of 6200°C

• 3.1 million atmospheres pressure and an interior temperature of 4950°C

• 3.1 million atmospheres pressure and an interior temperature of 6200°C

What caused the interior of Earth to separate into layers?

• The gravitational pull on materials and varying densities.

• A decrease in the rate of rotation of Earth.

• variations in heating by the Sun due to Earth's tilt

• collisions with meteors and comets

Which minerals contain the two most abundant elements by mass in Earth's crust?

• fluorite and calcite

• magnetite and pyrite

• amphibole and quartz

• galena and sulfur

Which list identifies minerals present in andesite from the greatest percentage by volume to the least percentage by volume?

• biotite, plagioclase feldspar, amphibole

• biotite, amphibole, plagioclase feldspar

• plagioclase feldspar, biotite, amphibole

• plagioclase feldspar, amphibole, biotite

Earth's inner core is inferred to be solid based on the analysis of

• seismic waves

• crustal rocks

• radioactive decay rates

• magnetic pole reversals

A seismic station recorded the P-waves, but no S-waves, from an earthquake because S-waves were

• absorbed by Earth's outer core

• transmitted only through liquids

• weak and detected only at nearby locations

• not produced by this earthquake

No P-waves or S-waves are received in the shadow zone because

• P-waves are absorbed and S-waves are refracted by Earth's outer core

• P-waves are refracted and S-waves are absorbed by Earth's outer core

• both the P-waves and S-waves are refracted by Earth's outer core

• both the P-waves and S-waves are absorbed by Earth's outer core

The distance from Albany, New York, to the epicenter of this earthquake is 5600 km. Approximately how much longer did it take for the S-wave to arrive at Albany than the P-wave?

• 4 minutes and 20 seconds

• 7 minutes and 10 seconds

• 9 minutes and 0 seconds

• 16 minutes and 10 seconds

How long after receiving the first P-wave from an earthquake centered 4000 kilometers away does a seismic station receive its first S-wave from the same earthquake?

• 5 minutes 35 seconds

• 1 minute

• 7 minutes

• 12 minutes 40 seconds