|MadSci Network: Earth Sciences|
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
Try the links in the MadSci Library for more information on Earth Sciences.