pure and applied geophysicsMarch 1976, Volume 114, Issue 2, pp 163–164 | Cite asIntroductory remarksAuthorsAuthors and affiliationsS. SaxovArticle 17 Downloads This is a preview of subscription content, log in to check access.Copyright information© Birkhäuser Verlag 1976Authors and AffiliationsS. Saxov11.AarhusDenmark