 Complete the following phrase:  The implications for civil defense of numerous surface bursts of high yield hydrogen bomb explosions on Pacific Proving Ground islands such as those of Ivy Mike in 1952 and Castle Bravo 15 Mt in 1954 were described in a 1957 report on The Effects of Nuclear Weapons, edited by Samuel Glasstone. A section in that book entitled Nuclear Bombs and the Weather states: The dust raised in severe volcanic eruptions, such as that at 