Earth heat production and radioisotopes, etc.

[JPreisig@AOL.COM]

Hmmmm,


      This is from:     jpreisig@aol.com   .


      Dear Radsafers,


            Hope all is well where you live and work.  It is hot and humid here

      in New Jersey.


            A while back, the John Jacobus fellow was asking about Earth

      heat flow and the various radioisotopes/radionuclides contributing

      to the Earth's heat flow.  A good book on this is Frank Stacey's

      "Physics of the Earth".  An appendix in the version I have describes

      which radioisotopes/radionuclides contribute principally to the Earth's heat 

      flow.  Possible Journals describing more recent thermal geophysics

      include Geophysical Journal International and Journal of Geophysical

      Research (which has various versions each addressing various fields

      of geophysics).


           As for fission driving Earth heat flow --- I don't know much about

      this.  I always thought the heat flow was simply due to radioactive decay.


           The Earth has an inner core, which is solid,  and an outer core, which

      is fluid.  Then there is the Earth's Mantle and crust (aesthenosphere,

      lithosphere, etc.).  Most of this is described somewhat in Stacey's book.

      The existence of the inner and outer core was discovered by looking

      at the paths taken by seismic waves through the Earth --- no need to 

      use neutrinos unless you really want to.


           As for having some "Inner Earth Vehicle" tunneling down into the 

      Earth, Good Luck!!!!  The Earth Pressures grow fairly quickly.  And as for having

      an experimental probe go into the Earth, it may get to a fair depth, but

      I believe any measurement electronics will fail miserably once the 

      temperature and pressure get high enough.


           Our current oil drilling efforts only extend about 5 or 10 miles (down)

     into the Earth.  Maybe more, for scientific drilling???  As these oil wells

     are drilled, sometimes well-logging is done to determine the properties

     of the wells as a function of depth.  Will there be oil, Will there be gas,

     etc.???  Well-logging is done with photomultiplier tubes (and other devices;

     neutron generators, etc.) which are specifically designed to withstand

     the thermal and shock (as well as pressure) environment of an oil well.

     See Schlumberger's web-site (Halliburton too???).  Some of their 

     technology is proprietary, and some is not.


          Anyway, I hope this is helpful, John Jacobus.


      Regards,                J.R. Preisig,  Ph.D.