The electromagnetic field induced by long and intermediate water waves (e.g., tsunami) is dependent on the time variation and spatial variation of the water motion and on the earth's electrical conductivity structure. The water motion is approximated by a plane progressive wave on a nonrotating flat infinite ocean of uniform depth....
Larsen, J. C.. 1971. "The electromagnetic field of long and intermediate water waves." Journal of Marine Research 29, (1). https://elischolar.library.yale.edu/journal_of_marine_research/1200