Fractal structure of marine measuring networks

Summary This paper deals with the fractal character of several distribution points measuring the Earth's total magnetic field (ETMF) during some marine surveys that we carried out in the Gulf of Pozzuoli and around the island of Ischia (Naples, Italy). Previous studies evaluated the fractal dimension of networks constituted by fixed measuring stations. The examined distributions display a ?fractal scaling? regime on 3–4 decades of distances with fractal dimensions of 1.80 and 1.54. These values characterize the whole investigated area covered by the distribution of experimental data. Linked to fractal dimension is the possibility of reconstructing the field and the capacity to reveal sparse and intense phenomena (e.g. magnetic anomalies) with a low fractal dimension. In distributions with large areas without measuring points, Shannon's theorem is no longer applicable in 2D. The fractal evaluation enables a spatial limit to record the phenomena to be defined and therefore establishes the minimum wavelength recordable of the magnetic field.