How do we know what is below the Earth's surface? We get clues from
- Extrusive igneous rocks
How do we know what is below the Earth's surface? We get clues from
Geological section of the Kola Super Deep Borehole derived from nearly continuous core extraction.
One of the most widespread urban legends is the story of the Russian scientists who drilled so deeply into the earth's crust that they accidentally broke through into hell.
The SAFOD Drilling project, which will monitor the San Andreas Fault at Depth.
Part of the Allende Meteorite, a carbonaceous chrondrite
All are helpful, but the best evidence we have comes from analysis of the physical properties of the Earth, which is the realm of Geophysics, and subdisciplines like seismology, potential field geophysics (gravity and magnetics), geoelectricity, and heat flow.
Because rocks are "opaque" we learn deduce all we know by inference, but is this any different from what we have been discussing so far (time vs. space)?
