Magnetometry

MAGNETOMETRY

Typical Magnetic Raising

Objective: Get information associated to geological formations by means of the magnetic characteristics of the rocks.

A) Fields Phase
Defining a mesh and in every node to measure the magnetic Total field T and its projections H and Z (Horizontal and Vertical).
NOTE: in the South Hemisphere Z points up.

B) Office Phase
- Drawing isolines of Z and H vectors.

Isolines of Z and H vectors

INTERPRETATION
- The orientation of the H vectors allows to situate the ends of the dipole
- To chart T along a profile also allows to delimit the magnetic body ("Leaning Profile")
- To chart simultaneously H and Z along a profile allows to know the dipole slope
- The Z chart along a profile allows to know the dipole depth
- Suggested interpretation program: Magix XL

During the interpretation it's important to remember that according to one of Maxwell's Equations, the magnetic monopoles doesn't exist. In other words, the T leaning profile will always show two maximun (S Pole and N Pole).

A magnetic prospection may determine:

* Magnetic minerals
* Hydrocarbures
* Space disposition of the dipole
* Geologic fractures

Magnitude order of the anomaly:

* Magnetite, hematite and pyrrhotite ~ 10⁴ g
* Semimagnetic association ~ 10³ g
* Hydrocarbure traps ~ 10² g

(Note: The poles position changes in the time)

The Future of the Magnetic Terrestrial Field (MTF)

Certain processes that happen inside the Earth cause that the MTF swings slowly: its magnitude weakens to get vanish and the reinforces an inverse sense. The process needs 700 thousand years, a fact that was probed by the "anomalous orientation" (in nowadays terms) of the magnetic minerals previous to the Pleistocene (once the matrix was solidified, the magnetic north of these minerals was pointing to the geographic south of the Earth (opposite to what happens today).

In the lapsus of 300 years the MTF has diminished a 15%. By extrapolation, the following annulment is going to be in the 40th century. In absence of the MTF, the compasses will not work and Van Allen's atmospheric belt (that protect us from cosmic radiation = mutagenic agent) will disappear. Curiously 700 thousands years ago, the first hominids appeared "explosively". Do we have to thank our existence to the MTF oscillation?


	Contact us!	MYSTERY: How can be detected an underground magnetic dipole?