book+2+chp.+1.3

III.Magnetic Earth A. Compass- device that has a magnetized needle that spins freely. Usually points north. B. Earth as a magnet 1. William Gilbert I. English Physician ii.1500s iii. interests-compasses iv. noticed always points in same direction v. thought Earth was a giant magnet 2.Earth has a magnetic field surrounding it and two magnetic poles 3.poles magnetized needle on the compass align themselves with Earths magnetic field 4. Earth's center-core-contains magnetic rock. Circulation of molten material in Earth's core is related to Earth's magnetism 5.magnetic poles-on Earth's surface where magnetic force is strongest I. not geographic poles C. Magnetic Declination- the angle between these 2 lines is the angle between geographic and the north pole to which a compass needle points I. Declination depends on location on Earth ii. Changes- magnetic poles move every year D. Earth's Magnetic Field 1. Earth itself can make magnets out of ferromagnetic materials. 2. Earth's magnetic field has completely reversed every million or so years 3. Molten materials come up through ocean floor- iron- lines up magnetic fields. E. Magnetosphere 1. Earth's magnetic fields extend into space I. affects movements of electrically charged particles in space 2. Van Allen- discovered them ii. contains electrons and protons at high speeds 3. Solar Winds- stream of electricity charged particles flowing at high speed from sun I. pushes 0against the Earths magnetic field and surrounds it ii. magnetosphere- region of Earth's magnetic field shaped by the solar wind a.) Constantly reshapes the magnetosphere as Earth rotates on the Earth's axis 4. Auroras- glowing region in the atmosphere caused by high speed charged particles from the sun that get close to Eartg's surface they interact with atoms in the atmosphere  I. Northern Hemisphere  a.) Northern lights or  b.)Aurora Borealis  ii. Southern Hemisphere  a.) Southern lights or  b.)aurora austrillas  Quiz 1.3  1.blue lines: solar wind  2.far red lines:magnetosphere  3. Each has a north magnetic pole and a south magnetic pole and magnetic field  4. No; because the Earth's magnetic poles are not located at the geographic poles  5. compass  6. magnetic declination  7. Aurora  8. Van Allen belts  9. magnetosphere  10. solar winds  Study Guide  5. your location on Earth's surface  6. Earth's magnetosphere is spread out farther on the side of the Earhyt not facing the sun  14, Aurora  15.Van Allen belts 23. As scientists studied rock produced from a molten material, they noticed that the domains of the iron in the rock had lined up in direction of Earhts magnetic field the domains of the iron in rock at different times line up in diff. directions this means Earths magnetic field has changed over time 30. Example: An iron bar is left laying in N-S direction for yrs, Earths magnetic fields may cause domains to lime up in same direction if you