Home arrow Space News arrow Latest Earth News arrow Its Confirmed: Earth Has a Solid Inner Core

Space Pages


Space Polls

Do you think the Universe was created by a Big Bang?
 

Its Confirmed: Earth Has a Solid Inner Core
Written by SerenaStargazer
Thursday, 28 April 2005
Scientists have discovered seismic shear waves in the Earth’s core, confirming that the core is solid. Shear waves, side-by-side oscillations like those generated by wiggling one end of a rope, can only exist in solids. Shear waves differ from pressure waves, such as sound waves. Pressure waves can pass through both solids and liquids and move more quickly than shear waves. Therefore, seismic waves would pass through a solid inner core in the form of shear waves, passing through more slowly than they would if the inner core were liquid.

Aimin Cao of the University of California, Berkeley, and colleagues calculated the speed at which seismic waves generated by large earthquakes in the South Pacific over the past 20 years traveled through the Earth. Their findings agreed with theoretical predictions which assume the Earth’s core is solid. Seismologists had previously assumed the core was solid by looking at how the Earth resonates after a major earthquake.
 
< Prev   Next >


© 2009 Space Travel Archive
Website Design York Interweb