Discrete Wavelet Transform for Multiple Decomposition of Gravity Anomalies

The Wavelet-based multi-scale analysis is a powerful tool for multiple decomposition of potential field data. Discrete wavelet transform generates low-order wavelet details that keep invariant scales with the total order number; while the change in the total order number can only increase wavelet details of high orders and the degree of smoothness of the final approximation. Thus, one can combine wavelet details based on regional geology to decompose gravity anomalies, producing anomalies correlated to certain geological sources. Applying the traditional frequency spectrum analysis techniques, one can estimate the everage depth of sources for every wavelet detail, and obtain the statistic correlation between the decomposed wavelet details and the source depth. A typical example for triple decomposition of local anomalies is given by using gravity data obtained from the Chinese continental scientific drilling site. An example for triple decomposition of gravity data from an Australian continental margin area is also presented.