Internal Structure of Earth

Information obtained from seismographs and other instruments indicate that the lithosphere may be divided into three zones crust, mantle, and core (see Eigure 1.1)  

As shown in the box on the next page, the controversy over whether earthquakes are generated because of wastewater injection and other fracking practices is bound to continue for some time. At present, most experts, including this author, are of the mind that the jury is still out. Scientists do not like to live by conjecture alone. There may be some truth to the earthquake fracking wastewater injection process, but the correlation has yet to be proven. 

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