Ocean median ridge region magnetic anomaly graph construction method and system based on direction constraint

Abstract

The invention provides a method and a system for constructing a magnetic anomaly graph of an ocean median ridge region based on direction constraint, and belongs to the field of geomagnetism and ocean magnetic force measurement, and the method comprises the steps: obtaining the total magnetic field intensity abnormal data of each measuring line of the ocean median ridge region; establishing shallow layer and deep layer equivalent sources of the ocean median ridge area; determining constraint conditions according to an ocean crust age model of an ocean median ridge region, the total magnetic field intensity abnormal data on each measuring line and a shallow equivalent source; based on the constraint condition and the inversion objective function, a precondition conjugate gradient method is adopted for inversion, and equivalent source physical property distribution (namely magnetization intensity) is obtained; performing forward modeling prediction on the magnetic field abnormal data of the blank area according to the equivalent source physical property distribution to obtain total magnetic field intensity abnormal data of the blank area; and finally, according to the abnormal data of the total magnetic field intensity on the blank area and each measuring line, determining the magnetic anomaly graph of the whole area of the ocean median spine, thereby improving the reliability of the magnetic anomaly graph of the whole area of the ocean median spine.

Description

technical field [0001] The invention relates to the field of geomagnetism and marine magnetometry, in particular to a method and system for constructing a magnetic anomaly map in a mid-ocean ridge region based on direction constraints. Background technique [0002] The marine magnetic anomalies provide extremely important evidence for ocean evolution, and can reflect the detailed information of plate tectonics. For example, the magnetic anomaly measured in the mid-ocean ridge region clearly records the history of ocean floor expansion. However, only sparsely distributed survey lines have been completed in the marine survey work in most regions, and the large gap between survey lines is likely to cause ambiguity in cognition of magnetic anomalies, especially the extension characteristics of magnetic strips. Faced with the above problems, the establishment of a magnetic anomaly map of the whole region has become an urgent need. [0003] To build the magnetic anomaly map of t...

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