Figure 6. The point distribution of the MGH-50 and MGH-2000
gravimetric network
The covered area (the area of the country) is approximately 93000
km2, the number of stations is more than 900 for both
the MGH-50 and the MGH-2000 networks, the gravity interval of the
country is approximately 350 mGal. The distance between gravimetric
stations is roughly 10 km, thus it provides a nice coverage of the
country for capturing the relevant features of the gravity field.
For historical reasons, however, most stations of the MGH-50 network
have been perished, accordingly, most points of the MGH-2000 are newly
established stations. In fact, there are only 13 identical stations of
the two networks (see common points in Figure 6). Apart from the change
of the gravity by time (which is not striking due to the moderate
tectonics of the area), the two networks are meant to present two
independent description of the same phenomenon, that is the gravity
field of Hungary.
Based on the gravity values of MGH-50 and MGH-2000 networks, gravity has
been interpolated onto a common grid, and the difference of the two
grids is displayed in Figure 7. Even though the difference between them
is in the range of some mGals, there are striking outliers reaching even
the 100 mGal value. This is very much, which cannot be interpreted
neither with the temporal variations of the gravity field nor with
observation errors. This difference is obviously a consequence of the
different sampling of the gravity field.