The Ground Shock Estimation calculates the vibration waves traveling through the ground while taking into account amplitude and the fact that vibration waves can take the form of a sin wave.
Resource:
"Formulae for Ammunition Management." International Ammunition Technical Guideline. 1st ed. New York: UN, 2013. 2-3.UN SaferGuard. United Nations Office for Disarmament Affairs (UNODA), 20 May 2013. Web. 12 June 2015. <http://www.un.org/disarmament/convarms/Ammunition>.
This equation, Ground Shock Estimation, references 1 page