Moscow has argued that seismic measurements based on vibrations in the earth are more accurate.
Both sides also made seismic measurements far from the test site of tremors in the earth.
Magnitude measurements are more sophisticated now, reflecting a change in technology and experience with seismic measurements.
The underlying structure can still be explored through magnetic, gravity and seismic geophysical measurements.
The official said that more work needed to be done, including new seismic measurements to better map the fields.
This, he says, would help improve the accuracy of seismic measurements.
The detonation is intended to check the accuracy of the American scientists' seismic measurements.
The Soviet side has emphasized a different approach in which seismic measurements are made from outside the test site.
The epicenters of over 4,000 earthquakes can be identified from seismic measurements taken since 1974.
Up to now, most verification has been done by "national technical means" - that is, through our own satellite observation or seismic measurements.