Name______Parent Signature______Mr. Jones

Geology Study Guide 1

a. Compare and contrast the Earth’s crust, mantle, and core including temperature, density, and composition.

Students will be able to name and label the layers of the earth. Students will compare and contrast each layer in terms of its temperature, density, and composition.

Basic knowledge includes the following facts:

  • The earth is layered with a lithosphere (crust and uppermost mantle), a convecting mantle, and a dense metallic core.
  • Each layer differs in composition, density, and temperature.
  • Temperature and density increases as depth increases.
  • The composition of the earth changes with depth and layers.
  • The crust is the upper part of the rigid lithosphere and is of different composition under land as opposed to the ocean floor.
  • Below the rigid lithosphere, the mantle consists of hot rock with semi-liquid consistency, which slowly moves or flows.
  • The outer core is molten, and the inner core is a dense solid.
  • The lithosphere is divided into separate plates which move very slowly in response to the mantle.
  • Heat from the mantle and core creates convection currents.
  • The Earth is made up of three layers—the crust, the mantle, and the core—based on chemical composition. Less dense compounds make up the crust and mantle. Denser compounds make up the core.
  • The Earth is made up of five main physical layers: the lithosphere, the asthenosphere, the mesosphere, the outer core, and the inner core.
  • Tectonic plates are large pieces of the lithosphere that move around on the Earth’s surface.
  • The crust in some tectonic plates is mainly continental. Other plates have only oceanic crust. Still other plates include both continental and oceanic crust.
  • Thick tectonic plates, such as those in which the crust is mainly continental, displace more asthenosphere than do thin plates, such as those in which the crust is mainly oceanic.
  • Knowledge about the layers of the Earth comes from the study of seismic waves caused by earthquakes.
  • Moving plates cause major changes in a world map over tens of millions of years.
  • Pangaea was the most recent of a succession of supercontinents that have formed and broken up over time.
  • The mantle is solid but capable of flow (like hot asphalt or fudge). Only under special conditions (at hot spots and along plate boundaries) does the mantle or crust melt to make magma, which may then rise to the surface to make a volcanic eruption.
  • Earthquakes represent sudden breaks in crust continuously stressed by plate movement. Gradually over time, the same movements result in major crustal features

Use the following terms to label the diagram below.

crustouter coremantle

inner coremesosphereasthenosphere

tectonic plate

Sample test questions (be able to answer these!!!!!!!)

1.How are the earth’s layers alike and different?

2.What challenges stand in the way of sending explorers to the center of the earth?

3.How does the movement of lithospheric plates cause major events on earth’s surface?

4.What evidence do scientists have that continents were once joined together?

5.Why do mountains often occur in ranges thousands of kilometers long?

6.What can fossils tell us about movements of the plates in the past?

Students will understand that:

  • The earth is layered with a partly molten, metallic core; a mantle that though solid, is hot enough to flow; and a colder, rigid lithosphere.
  • Lithospheric plates on the scales of continents and oceans constantly move.
  • Major geological events, such as earthquakes, volcanic eruptions, and mountain building, result from these plate motions.
  • Some changes in the earth’s surface are abrupt (such as earthquakes and volcanic eruptions) while other changes happen very slowly (such as uplift and wearing down of mountains).