Applied Geophysics: amazing and polivalent tool (I)

Geophysic come from two greek words, one is "geo" which means "earth" and "phisica" (τὰ φυσικά) which menas "nature", so as geophysics is the estudy of the earth´s nature.
This science has two diferents pathways, one mainly performed by physicist and geologist ussualy called "pure" that is in charge of big scale fenomena related to the planets and, at the same time, is ussualy divided in two parts: inner and outter.

The other one is called "applied" (AG) and is mainly performed by engineers but also geologist and is in charge to use the principles of the "pure geophysics" applied to the engineering projects. Also it has two parts: superficial applied geophysics and wellbore geophysics.

Nowadays, in my opinion, wellbore geophysics is also called well-logging, and if we consider the study of the well core samples of physical properties we can speak about "petrophysic" as a part of the geophysic (if we asume that another issues like "geomechanic" is also part of the geophysic), in the same way that the mechanic is a part of the physic.

In some sources, applied geophysic is also calle geotechnics when is applied to the civil engineering to study rock and soils physical properties and when design is included (tunnel, foundations, dams, roads...) is called geotechinical engineering. So it is possible to say "geophysical engineering" in general when we use indirect methods to dertermine the subsurface materials properties, and "geotechnical engineering" when we use direct methods, labtest and we have to design structures. Both ones, geotechnicians and geophysicists and even the petrophysicists, must know about direct and indirect methods in order to correlate results and work as a team.

Anyway, this tool (AG) is incredible polivalent, is mainly but not only iused in the oil and gas industry for exploration and production, also in civil engineering in order to study the engineering properties of the rock and soils without use another kind of test (geotechnical test), also in hydrogeology, oil and gas exploraton and production, arqueology, environment...