Recent MAGSAT results

Meyer, et al. have improved their original global crustal model and made a spherical harmonic analysis of the resulting magnetic field to n=50. The Z contours at 400 Km altitude from a field model composed of the first 15 degrees and order of their model and the terms n=16 to 29 from the MAGSAT model M051782 are presented. The main point to consider from such representations is that the lower order terms appear to contribute components comparable in magnitude to those of higher order. Thus, one should allow in making tectonic interpretations of global maps of anomalies such as those published by Langel, that there are likely continental scale (or smaller) features that have been removed along with the core field by the subtraction of the terms n=1 to 13 of the observed field. Planning for the analysis of data to be accrued by GRM should thus address this problem.