Re: How have we found out what the interior of the earth looks like

Dear Charissa:

Scientists have determined the internal structure of the Earth by studying 
the travel of seismic (earthquake) waves.  The behavior and velocity of 
seismic waves is dependent on the material through which they are 
travelling.  Some waves slow down or do not even travel through some 
materials, while other types of seismic waves travel very fast.  From 
studying these waves scientists have been able to produce an image of the 
structure of Earth's interior.

Best Regards,

Rick De Van
rdevan@rtd1.com

[Moderator note:  There has been a proposal to use particles such as neutrinoes 
and muons to probe the interior of the Earth in a manner similar to how a CAT 
scan can image the human body.  If this is at all practical, it will take a few 
years to develop.]