Period 01 : (1) The time interval between passages, at a fixed point, of a given phase of a roughly periodic oscillation, or more specifically, of a simple harmonic wave. It is the reciprocal of frequency. (2) See geologic period
Intergovernmental Oceanographic Commission IOC technical series 37, Tsunami Glossary (A glossary of terms and acronyms used in the tsunami literature - English), , United Nations Educational, Scientific and Cultural Organization UNESCO, Paris, France 1991. http://unesdoc.unesco.org/images/0008/000885/08853 8eb.pdf, (ND/ Tsunami Sci - Brit) {590}