Presentation title
/12/2006 31/12/2006 03/01/2007 06/01/2007 6 © Copyright QinetiQ limited 2006 www.QinetiQ.com Ground level neutron increases for 23 February 1956 Impulsive event: no advance warning! Leeds 4581% (highest on record) Ottawa 2802% Chicago 1976% Wellington 575% Increases at Mexico and Peru indicated