Unit II: Planetary Tectonics

• Compare and contrast the tectonic processes (past and present) on the terrestrial planets. Also be able to compare and contrast the tectonic landforms on the terrestrial planets.

Read This Material in Your Text:

• Seeds, 5th Edition - Section 8.1
  • Earth - Section 8.2 (Focus on the material on tectonics and volcanism)
  • Mercury - Section 8.4 (Focus on the material on tectonics and volcanism)
  • Venus - Section 8.5 (Focus on the material on tectonics and volcanism)
  • Mars - Section 8.6 (Focus on the material on tectonics and volcanism)
• Seeds, 4th Edition:
  • Earth - Section 6.1 (Focus on the material on tectonics and volcanism)
  • Mercury - Section 7.1 (Focus on the material on tectonics and volcanism)
  • Venus - Section 7.2 (Focus on the material on tectonics and volcanism)
  • Mars - Section 7.3 (Focus on the material on tectonics and volcanism)

In a previous objective you studied plate tectonics on the Earth. Tectonics on the Earth is by far the most complex of the terrestrial planets. Mercury has plains composed of basaltic lava. Lightening, fresh lava flows and other relatively youthful volcanic features suggest that Venus may still be tectonically active. Mars has the largest volcanoes in the solar system. However, it has been tectonically inactive for at least 2 billion years. Although all terrestrial planets exhibit either past or present tectonic activity, the Earth is the only terrestrial planet that exhibits 'plate tectonics'.

After completing objectives 10 & 11, you should be able to compare and contrast the tectonic processes (past and present) on the four terrestrial planets. You should also be able to compare and contrast the tectonic landforms on the terrestrial planets. When comparing and contrasting tectonic processes and landforms on th e terrestrial planets, you might think in terms of the following questions:

1. Is tectonic activity currently active on the planet? Why or Why not?
2. If tectonic activity is no longer active on the planet, what was the nature of past tectonic activy? What landforms were produced?
3. If tectonic activity is still active, what is the nature of that tectonic activity. Is full-blown plate tectonics active on the planet? Why or why not?
4. If tectonic activity is still active on the planet, what landforms are present?

Complete These Self-check Questions: These questions and their answers are designed to help you determine how well you understand this objective and to provide additional instruction.

• There are no self-check questions for this objective.

Homework Questions: Answer these homework questions after reading the on-line lecture and the readings in the text. Complete the self-check questions before attempting the homework. Follow the instructions for submitting the homework on this unit homework page.

• There are no homework questions for this objective. See the posted discussion questions for this unit.

Discussion Questions: After studying this objective be prepared to contribute to the following discussion questions. Follow the instructions on the Unit Discussions page to submit your contribution.

• Tectonics and Volcanism on Terrestrial Planets: To varying degrees the surface of the terrestrial planets have been modified by tectonic processes on the planet. For example, the distribution of the landmasses, the shape of the oceans, the distribution of mountain ranges and earthquake activity on the Earth are the result of tectonics on the Earth. Although Mercury, Mars and Venus are not as tectonically active as the earth, they have all experienced some degree of tectonic activity. Choose one of the terrestrial planets and describe how tectonic activity has help to shape the planet either today or in the past.

  IMPORTANT: The word tectonic refers to internal activity on the planet that may manifest itself externally. For example, earthquakes originate inside a planet, but can its signs are visible on the surface. The word tectonic DOES NOT NECESSARILY ALWAYS REFER TO PLATE TECTONICS.

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