RTP_Melo_Barbosa_SBGf_2019.pptx (5.62 MB)
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Reduction to the pole in Fourier domain – good and bad filtering of real data in Brazil

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posted on 2019-08-23, 11:32 authored by Felipe F. MeloFelipe F. Melo, Valeria C. F. BarbosaValeria C. F. Barbosa
Reduction to the pole (RTP) is a popular filter that
simulates how the magnetic data would be if both the
geomagnetic field and the magnetization of the source
were vertical. This process locates the horizontal position
of the source through the maximum amplitude of the
reduced-to-the-pole anomaly; therefore, it assists in the
geologic interpretation. To perform properly the RTP is
necessary the knowledge of the magnetization directions
of the source and the ambient field. However, the
magnetization direction of the source is rarely known.
Other issue in RTP is its instability at low latitudes; at these
locations, the traditional RTP results are useless. We
analyze the RTP results of simulated magnetic data at
different latitudes, generated by sources with induced and
remanent magnetizations. These synthetic tests closely
resemble real data from Brazil. Then, we apply the RTP to
total-field anomalies in distinct locations from south to north
part of Brazil. These locations encompass data from mid to
low latitudes: Dom Feliciano Belt, Goiás Alkaline Province
and Carajás Mineral Province. The reduced-to-the-pole
anomalies of these datasets exemplify good and bad
filtering of real data in Brazil.


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