Structure function method extracting fault anomaly from geophysical prospecting gravity anomaly

Abstract

The invention discloses a method extracting fault anomaly from geophysical prospecting gravity anomaly and belongs to exploration geophysics in the earth sciences. An existing method for separating regional anomaly and local anomaly (a trend analysis method, a frequency domain filtering method, a moving average method, upward extension and the like) has the defects that the boundary effect is obvious and spatial structural characteristics of the regional anomaly are not considered, and accordingly the separated and extracted regional anomaly is not high in accuracy. For obtaining a high-accuracy method for separating the regional anomaly and local anomaly of the fault, a structure function method is given. Under the condition that a spatial distribution geometrical characteristic, a covariance function and the regional anomaly form of gravity observation data are known, the fault region anomaly is obtained by means of the optimal, linear and unbiased interpolation estimation method. The trend analysis method is only a particular case of the structure function method. The structure function method is suitable for separation and extraction of the fault gravity anomaly with a linear structure. An experiment proves that the structure function method is effective and feasible on the aspect of implementation.

Description

[0001] One. Technical field: the present invention relates to a kind of method extracting fault anomaly from geophysical gravity anomaly, according to the national standard of the People's Republic of China " subject classification and code ", the present invention belongs to " exploration geophysics (coding: 1702065)", that is, applied geophysics (geophysical prospecting, geophysical prospecting). 2. Background technology [0002] The importance of faults in geological research is self-evident. For example, active deep fault zones are generally earthquake-prone seismic zones (such as the Pacific Ocean seismic zone and the Sichuan 521 seismic zone). Gravity anomalies in exploration geophysics (referred to as geophysical prospecting) can generally reflect such deep and large fault zones, which appear as gravity anomaly gradient zones. This kind of fault gravity anomaly has obvious spatial structure, that is, linear, and has a very long direction (for example, tens of axioms or ...

AI Technical Summary

Problems solved by technology

Due to the lack of consideration of the spatial structure characteristics of geophysical gravity anomalies, this leads to a large difference between the regional anomaly values ​​obtained by applying them (conventional methods) and the real regional anomaly values

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