Observations of temporary plant stress induced by the surface shock of a 1-kt underground chemical explosion

Abstract

The Non-Proliferation Experiment (NPE) involved carefully monitoring a 1-kt chemical underground explosion using extensive seismological measurements and low-altitude overhead imagery. Lawrence Livermore National Laboratory has conducted a study to determine whether the multispectral overhead imagery acquired during the NPE can be combined with other techniques to locate the ground zero (GZ) of an underground nuclear explosion within the seismic error ellipse. This report describes the use of such overhead images to detect the changes in plant metabolisms, normally referred to as plant stress, that appear to have been induced by the surface accelerations caused by the NPE underground explosion. The metabolic condition of the plants on the surface above the explosion point was determined using a published plant stress measuring methodology to analyze the multispectral images taken from a low-flying aircraft. The surface areas that experienced accelerations greater than 0.2 g show measurable plant stress, within 56 hours of the underground explosion, in all of the plant species. The pattern of the plants` stress generally follows the pattern of the measured surface acceleration. Seven days after the explosion, the levels of apparent plant stress had relaxed to about one-third what they were 56 hours after the explosion, while the patternmore » of the apparent plant stress remained the same.« less