A unit of angular measure; one radia^ is that angle whose intercepted arc on a circle is equal in length to the radius of the circle. Thus, ;r radians equals 1800. See also: degree (2)
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}