Seismic moment seismic moment tensor formula_8 (a symmetric tensor, but not necessarily a double couple tensor), the seismic moment is Seismic moment Seismic moment is a quantity used by seismologists to measure the size of an earthquake. The scalar seismic moment formula_1 is defined by the equation formula_2, where formula_1 thus has dimensions of torque, measured in newton meters. The connection between seismic moment and a torque is natural in the representation of seismic sources as a pair of force couples. Seismic moment is not a measure of energy. The relations between seismic moment, potential energy drop and radiated energy are indirect
Seismic vibrator measured in pound-force. To transmit a maximum force to the ground and prevent the shaker from bumping, part of the weight of the vibrator is applied to the shaker. Seismic vibrator A seismic vibrator is a truck-mounted or buggy-mounted device that is capable of injecting low-frequency vibrations into the earth. It is one of a number of seismic sources used in reflection seismology. The ‘Vibroseis’ exploration technique (performed with vibrators) was developed by the Continental Oil Company (Conoco) during the 1950s and was a trademark until the company's patent lapsed. Today, seismic vibrators are used to perform about half of