Comparison in 1931 of the findings of field investigation in 1930 of the earthquakes of February 25 and March 1 of that year in the Imperial Valley, California, with disturbances to leveling found in the 1931 retracement of precise leveling surveyed in 1926-1927, and 1928, by the U. S. Coast and Geodetic Survey led to the conclusion that there was no discernible correlation except in one instance, and that doubtful.

Occurrence of the 1940 earthquake with disclosure of a surface fault offset necessitates review and reconsideration. The revised conclusion is that two of the disturbances to leveling found in 1931 may probably be correlated with activity on this fault zone, but that the disturbances are quite as likely due to secondary effects caused by shaking as to primary surface warping or tilting and probably more so.

The necessity of frequently repeated precise surveys is emphasized.

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