December 13, 2012 | 1 A few seconds after the beginning of the
directed blast, life within roughly ten kilometers (6.2 miles)
of Mount St. Helens within the blast zone was about to be
extinguished. “Directed blasts,” Rick Hoblitt, Dan Miller, and
James Vallance wrote in their 1981 paper on the blast deposits,
“typically devastate large areas… and kill essentially all
above-ground life within these areas.” Human and animal,
arthropod and avian, tree, bush and flower, all perished.
Between its kinetic and heat energy, the directed blast released
the equivalent of 24 megatons of energy in a few short moments.
This is one megaton short of the theoretical yield of the
largest hydrogen bombs the United States ever created; the first
nuclear bombs to destroy a city were only 15 and 21 kilotons,
respectively – orders of magnitude smaller. Instruments
measuring the blast saw “amplitude variations comparable to
those caused by detonation of nuclear devices in the 1-10 mt
[megaton] range.” There are words for eruptions