Abstract
The data for the mean sea levels at Lagos (Lisbon), Portugal, during the period from October 1908 to December 1958, were taken from Publication Scientifique, Monthly and Annual Mean Height of Sea Levels. The investigation was made with the intention of finding some evidences, if there exist abnormally large changes in the height of yearly mean sea levels preceding the occurrence of great earthquakes similarly ac :n the cases of the Kwanto Earthquake in 1923, the Nankaido Earthquake in 1946, the Niigata Earthquake in 1964 and others in Japan, concerning the problem of predicting the occurrence of great earthquakes. The analysis was made similarly as in the cases of San Fransisco[2] and Los Angeles [3] in United States of America, as there are no data for sea water density and barometric pressure in my hand.
