Mass transports on the surface impart a space motion to the earth. The shift induced by seasonal atmospheric pressure variations is calculated. The magnitude of the displacement is approximately 1.61 cos [(sun -9 ø)]1 mm where (sun) is the sun's longitude measured from the beginning of the year. The motion is thus too small to be detected at present. Deformations of a model earth caused by atmospheric loading are estimated. The seasonal distortions over parts of Asia and Greenland approach the l cm measuring goal of the new laser ranging techniques and exceed it over the Antarctic continent. They are not generally significant in other parts of the globe. The results are depicted in contour form on world maps for each of the four seasons. Pilot studies for the effect on the location of the geocenter of seasonal variations in air-mass, groundwater, and sea-level were carried out by Stolz [1976a, b]. The composite shift amounts to only a few millimeters, which is somewhat below the accuracy objective of the above-mentioned new techniques. The problem bothered Schumann [1903] early this century. Giving the newly discovered Kimura term as possible evidence, Schumann [1903] investigated whether a 5-m geocenter displacement, caused by periodic or secular mass transports on the crust, could be detected from the then existing complex of latitude observatories. His conclusion was that the network geometry was not sensitive enough to resolve the shift. The Kimura term was again taken as likely evidence for geocenter motion by Munk and MacDonald [1960] and by Sugawa et al. [1973]. Initial estimates for the component of the term attributable to a shift of the geocenter were made by Paper number 9B0154.

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