Disruptive bodies
In geophysics and potential theory, a disruptive body is a body that causes irregularities in the earth's gravitational or magnetic field .
Disruptive bodies stand out from their surroundings by at least one clearly different rock parameter, in particular:
- the rock type or mineralization,
- the rock density ,
- the porosity or the water content ,
- the magnetization .
They can be of purely scientific interest (such as the Ivrea body for geoid determination in Switzerland) or have economic importance as a deposit - e.g. B. Ores , special rocks such as kaolin or serpentine , petroleum -höffige layers or construction and bulk raw materials .
Normal field, anomaly and interference potential
The difference to the surrounding rock can be determined by precise measurements in a force field over relatively large distances by comparing the measured field (e.g. gravity ) with its normal field typical for the respective region . The difference is called an anomaly ( magnetic or gravity anomaly ) and is represented graphically or digitally in the form of so-called isanomal maps. The location and structure of the disruptive body can then be deduced from the local course of these anomalies.
The exact mathematical-physical analysis of the anomaly field is carried out with the help of the interference potential or the potential-theoretical divergence , for which there are a number of approximation methods. Because in general neither the location of the disruptive body nor the calculation of its properties is clear; one must first adopt approximate values and gradually adapt them to the measurements by making targeted changes to the modeling (“ trial and error ”). In most cases, additional data from geology , for example, are required (e.g. on outcrops , observed faults or crevices , edges of sedimentary basins , etc.) in order to be able to narrow down the location of the disruptive body sought.
Other meanings of the term "disruptive body"
- in astronomy: a celestial body that causes orbital disturbances in the orbit of a planet or moon
- In technology, floating or missiles that are intended to create disturbances or turbulence in a smooth flow (e.g. in stilling pools or the water vortex brake )
- in the military, reflex bodies intended to complicate the enemy's radar or air defense .