The pioneer work in Japan stimulated surveys in many other part of the world, most frequently in regions of active seismicity where such research has obvious practical value. In the USSR, instance, peated surveys of part of the Caucasus have disclosed marked differential displacement, with certain blocks being elevated at about 4 mm yr and a number of marginal basins subsiding at about the same rate. The pattern is very of that recorded in Japan, but the rates of movement are on the whole rather some of the most striking results of geodetic levelling come from California where over 80 000 km of repeated traverses have defined quite clearly regions of both elevation and depression Repeated surveys in the Los Angeles area have disclosed considerable variations in the rates at which local hill ranges are being uplifted, among the fastest is the Tehachapi (for location see Fig. 4.5) which is rising at 15 mm yr-1. Even more dramatic was the discovery of the Palmdale Bulge on the San Andreas fault which was at first thought to have been uplifted by 200 mm in little more a year, possibly as than followed precursor to a major earthquake. However, no and some doubt has been on the accuracy of this that Yet the of year and the interval between surveys can be reduced to less than a results still obtained. separate displacements California have detected annual vertical figures plex ranging from zero to 26 mm. high that decadal Two or two sites suggest movement is probably pulsatory and that decadal averages may conceal a very episodic motion.