Earth Interior: Practice, Assignment, and Quiz

How thick is the outermost layer of the Earth?

100 km

Earth's inner core is a. a dense ball of solid metal. b. a layer of molten metal. c. a layer of hot rock. d. a layer of rock that forms Earth's outer skin. Please select the best answer from the choices provided

A

The part of the mantle called the _____ is made of soft rock that bends like plastic.

Asthenosphere

Earth's magnetic field results from movements in the a. mantle. b. outer core. c. inner core. d. crust. Please select the best answer from the choices provided

B

Earth's mantle is a. a layer of molten metal. b. a layer of hot rock. c. a dense ball of solid metal. d. a layer of rock that forms Earth's outer skin. Please select the best answer from the choices provided

B

Using data from seismic waves, geologists have learned that Earth's interior is made up of several a. continents. b. layers. c. ridges. d. trenches. Please select the best answer from the choices provided

B

Holes drilled several kilometers into Earth's crust provide direct evidence about Earth's interior in the form of a. seismic waves. b. rock samples. c. liquid iron. d. volcanic eruption. Please select the best answer from the choices provided

B.

______ is a rock with a fine, dark texture that makes up the oceanic crust.

Basalt

How do geologists use seismic waves to learn about the Earth's interior?

Because geologist cannot directly study the interior of Earth, they often use information from seismic waves to infer information. The speed of the waves and the paths that they take through the Earth can tell geologists a lot about the materials though which they travel.

Compare and contrast the two upper layers of the mantle.

Both the lithosphere and the asthenosphere are part of the Earth. Lithosphere is made up of Earth's outermost layer, the crust, and the uppermost portion of the mantle. In comparison, the asthenosphere is the upper portion of the Earth's mantle, which is also the Earth's middle.

Scientists think that the __________, made of liquid iron and nickel, moves to produce Earth's magnetic field. a. crust b. mantle c. outer core d. inner core Please select the best answer from the choices provided

C

Geologists obtain indirect evidence about Earth's interior by a. measuring pressure differences at Earth's surface. b. estimating temperature inside earth. c. directly looking under the many layers. d. recording and studying seismic waves. Please select the best answer from the choices provided

D

What can geologists learn about the interior of Earth from rock samples?

Geologist use rock samples to learn more about conditions deep inside of the Earth. Using rock core samples and rocks ejected from deep underground, geologists are able to infer information about the conditions under which the rocks were formed.

Based on the diagram, describe one of the major differences between oceanic crust and continental crust.

It is the solid rock layer upon which we live. It is either continental or oceanic. Continental crust is typically 3050 km thick, while oceanic crust is only 510 km thick. Oceanic is denser, can be subducted, and is constantly being destroyed and replaced at plate boundaries.

How is the Earth's magnetic field generated?

Scientists think that the Earth's magnetic field is generated by movements in the liquid outer core.

Earthquakes produce ______ that travel though Earth

Seismic waves

Describe the Sial.

Sial are the rocks that are rich in silicon and aluminum. In geology, the term 'sial' refers to the composition of the upper layer of the Earth's crust, namely rocks rich in silicates and aluminum minerals. It is sometimes equated with the continental crust because it is absent in the wide oceanic basins, but "sial" is a geochemical term rather than a plate tectonic term.

Describe tectonic plates and explain how they "float" on the Earth's surface (what do they float on and what causes their movement).

The asthenosphere contains materials more dense than those of the tectonic plates lying above, which enables plates' floatation. The positioning of tectonic plates above the asthenosphere and resulting movement is just one small part of how tectonic plates work. The Earth's crust forms from many other layers of of sedimentary deposit, which form above and below the asthenosphere. Above the asthenosphere, lies the lithosphere, which occurs in continental and oceanic forms. The continental variety contains materials of lighter weight than those in the oceanic form. Tectonic plates might form from either substance. Regardless of composition, all plates have the same ability to move via flotation. The movement of tectonic plates varies depending on several factors, including weight and size. Heavier plates, or plates with heavier areas, sink more quickly than lighter ones. Over time, these plates dissolve into the lithosphere. One plate might sink beneath the edge of another, causing a subduction zone. Fluids from moving plates rise to the surface, escaping into surrounding water or air, ultimately producing magma and lava.

The asthenosphere is part of which layer of Earth?

The asthenosphere is part of the mantle, or second, layer.

Pressure increases with depth toward the center of Earth. In which layer would you expect pressure to be the greatest?

The inner core because the lower you are the more pressure is on your body.

Which layer of Earth is made up partly of crust and partly of mantle material?

The lithosphere is made of the crust and the upper part of the mantle.

Compare and contrast the outer core and the inner core.

The outer core is hot, molten iron and nickel under extreme pressure. Convection currents cause movements in the liquid outer core. Scientists hypothesize that these movements cause Earth's magnetic field. The outer core surrounds the inner core, which occupies the center of Earth. The inner core is also iron and nickel and is also extremely hot. But pressure within the inner core is so great that it remains a solid.

Earth's solid inner core is surrounded by the hot, molten metal of which layer?

The outer core is liquid nickel and iron which surrounds the inner core that is solid nickel and iron.