Author Question: What key features have emerged through the examination of the map of Earth's magnetic field? What ... (Read 14 times)

APUS57

  • Hero Member
  • *****
  • Posts: 571
What key features have emerged through the examination of the map of Earth's magnetic field?
 
  What will be an ideal response?

Question 2

How does convection work?
 
  What will be an ideal response?



heinisk01

  • Sr. Member
  • ****
  • Posts: 329
Answer to Question 1

Answer: 1. The pattern of Earth's magnetic field very closely, but not exactly, resembles the field of a bar magnet. The analogy works only if the hypothetical magnet producing Earth's field is located deep in the interior. This observation, made in the nineteenth century, led to the conclusion that Earth's magnetism originates deep within Earth and not at the surface or somewhere in space.
2. The north magnetic pole, where the force lines go into Earth, and south magnetic pole, where the force lines emerge, do not coincide exactly with the geographic north and south poles. Currently, the angular distance between the magnetic and geographic poles is about 18 degrees.

Answer to Question 2

Answer: Convection is the simultaneous movement (transfer) of matter and heat, whereas conduction transfers only heat from hot to cold regions. Convection happens when gravity forces that cause motion are greater than viscosity forces that resist motion; in other circumstances, heat transfers by conduction. Thermal convection originates from density contrasts between got and cold materials. Higher density contrast, which favors convection, is present in materials that have low heat conductivity and large expansion when heated. Calculations show that convection should occur in the whole mantle and in the outer core, but not within the lithosphere or inner core. Convection in the outer core results from density variations caused by compositional differences, rather than by temperature differences that cause mantle convection.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

More than 30% of American adults, and about 12% of children utilize health care approaches that were developed outside of conventional medicine.

Did you know?

Cyanide works by making the human body unable to use oxygen.

Did you know?

Most fungi that pathogenically affect humans live in soil. If a person is not healthy, has an open wound, or is immunocompromised, a fungal infection can be very aggressive.

Did you know?

Adolescents often feel clumsy during puberty because during this time of development, their hands and feet grow faster than their arms and legs do. The body is therefore out of proportion. One out of five adolescents actually experiences growing pains during this period.

Did you know?

After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.

For a complete list of videos, visit our video library