Earth's magnetic field resembles the field around an electromagnet.
Self-exciting dynamo - best model for explaining behavior of Earth's magnetic field
Magnetic Field is irregular and constantly changing (declination and field strength)
Paleomagnetism
- study of how E's magnetic field behaved in past
-Curie Point
-depositional remnant magnetization
-thermoremnant magnetization

Paleomagnetic studies reveal:
1) Polar wandering
2) magnetic "reversals" in terrestrial rocks
3) magnetic stripes on sea floor

Review Questions
1. Use a labeled diagram to illustrate the magnetic flow lines around the Earth. What evidence supports the hypothesis that the Earth's magnetic field is generated in the outer core.

2. How has the study of paleomagnetism provided supporting evidence for the theory of sea floor spreading.

3. Explain the concept of polar wandering. Your answer should include information on how it is detected, its rate, and what information it provides us about the development of the Earth.

4. Explain how a magnetic "signature" is imparted to both sedimentary and igneous rocks.