[en] To check up the validity of an assumption on the constancy of potassium specific radioactivity Asub(k) in seawater, 14 samples selected from the Pacific Ocean in 1982 at different depths and geographic coordinates have been investigated. The Asub(k) mean value in these samples is shown to coincide with the potassium aspecific activity in terrestrial rocks. However some deviations related to sampling latitude and deoth have been observed. The deviations are associated with the entries of cosmic and volcanic substances