It may seem a boutade but fact is that we know much more about the Cosmos above our head, than on the Earth below our feet and this is, after all, a stark reminder of our great limitations.
Large sums of money are invested annually for exploring the outer space but very little is invested in exploring the inner structure of our Planet.The shifting of the Pole by 17 cm per year towards Europe, which was announced yesterday – perhaps due to the melting of the ice capt – reminds us how important is to understand the inner structure of our beautiful planet.
Another alarm bell are the recurring earthquakes which are destroying cities and causing tsunamis. It goes without saying that knowing better the lower levels of the Earth will help us to forecast them more accurately and give us time to prepare for them.
Our knowledge of the inner layers of the Earth is mainly due to scientific guessing. We use gravity pull and gravimetric experiments as a yardstick but we are not really sure about the results. Deep drilling have never gone beyond the crust up to the Upper Mantle, which extends from 210 to 270 km in depth. We are not even sure if the Inner Core is really solid, as it is claimed: made of iron and nickel.
The inner layering of Earth were mainly inferred indirectly, for instance using the time of travel of refracted and reflected seismic waves created by earthquakes. Here is our Earth could be layered:
Lithosphere (from 0 and 60 km)
Crust (from 0 to 35 km)
Uppermost part of mantle (35-60 km)
Mantle (35-2890 km)
Upper Mesosphere (upper Mantle 210-270)
Lower Mesosphere (lower Mantle 660-2.890 km)
Outer Core (1.790–3.160 km)
Inner Core (5.150-6.360 km)
An effort should be made to drill up to at least the Mantle, even before getting on Planet Mars. We do believe that we should get at least to 200 Km below the surface by 2030, and the founding of such enterprise – which remind us the famous book by the visionary writer Jules Verne – should easily reap great profits in the process by mining rare minerals, gold and diamonds. Furthermore, money could be made not only by extracting elements but also by extracting heat and energy. Deep placed heat-exchangers and electricity generators could allow us to move on the surface large quantity of energy, abandoning coal, petroleum and nuclear energy.