How are seismic waves used to determine the structure of earths interior?

3 comments

1. 

   Elizabeth H on April 16, 2010 at 7:00 pm

   Seismic waves travel through the Earth as vibrations. A seismometer is an instrument used to record these vibrations
   Mohorovicic discovered the boundary between crust and mantle, thus it is named the Mohorovicic Discontinuity or Moho, for short. The composition of the crust can be determined from seismic waves by comparing seismic wave velocities measured on rocks in the laboratory with seismic wave velocities observed in the crust. Then from travel times of waves on many earthquakes and from many seismic stations, the thickness and composition of the crust can be inferred.

2. 

   Johnka on April 16, 2010 at 7:00 pm

   The waves travel at different speeds through different materials especially solid rock and molten rock. By measuring the time of arrival of seismic waves from an earthquake the size of the molten core can be estimated.

3. 

   astrorami on April 16, 2010 at 7:00 pm

   scientists dont use seismic waves, they travel to the center of the earth in their cars.