abstract
Photographic measurements of the earth-surface displacement were made on the gnome event, an underground nuclear detonation near Carlsbad, New Mexico, November 1961. One long range and three short range photo stations were used to provide complementary coverage. Motionless inertia weights were measured against graduated targets rigidly anchored to the surface. The experiment is described in detail including target/weight arrangement, camera specifications, and photo station locations in relation to Surface Zero. Analysis of results from 6 films from close-in stations and one film from the long range station are reported. The peak displacement measured was slightly greater than six feet at a location 106 feet from surface zero.