According to link from other post in this thread, the earth's crust is 20 mi thick on average under the continents and 3 mi thick on average under the oceans. Using the 71% ocean ratio, we get the average thickness of the crust is 7.93 miles; applying our formula for volumes, the volume of the crust would be:
Volume crust = 4/3 * pi * (r1^3 - r2^3)
= 4/3 * pi * (3963^3 - 3955.07^3)
= 4/3 * pi * (62240377347 - 61867493758)
= 4/3 * pi * 372883589
= 1,561,931,148 cu miles
From earlier post, volume of ocean = 378,080,439 cu miles
Ratio of solid crust to ocean = roughly 4/1 (earth's crust is approximately 80% solid and 20% water)
If 5% of crust = Fe, then there is 4% iron in crust compared to 20% water (5:1 ratio); ignoring the negligible amount of iron dissolved in seawater (< 10^-9 moles/kg), I still think the magnetic properties of the iron would have far greater effect on earth's magnetic field than the electrolytic/conductive properties of sea water - what are your thoughts?
I don’t believe that the solid crust contributes to the creation of the magnetic field. I think it’s creation is due to the motion of the molten conductive iron in the liquid portion of the Earth’s core.