Re: What is the origin of the Earhts magnetic field?

Hi Renee.
This is a great question that has been asked by many people. Albert 
Einstein believed the question of the Earth's magnetic field to be one of 
the most important unanswered questions of physics. It does not have a 
simple answer and the cause of the magnetic field is not completely 
understood. 
The Earth's magnetic field appears to be the result of the dynamo effect. 
This is the same idea that is used by electric motors. The inner core of 
the earth is comprised of solid iron and nickel. Surrounding the inner core 
is an outer core that is made of liquid iron and nickel. Surrounding the 
outer core is the semi - liquid mantle.
 http://pubs.usgs.gov/gip/interior
/

The inner core and outer core are rotating at slightly different speeds. 
This differential rotation and the convection currents in the outer core 
are believed to be responsible for the generation of the earth's magnetic 
field. I have supplied several links that explain the process.

 http://ees-www
.lanl.gov/IGPP/EarthsMagneticField.html
 http://www.ems.psu
.edu/info/explore/EarthMag.html
 ht
tp://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magearth.html
 http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magearth.html#c2