Seismic Detection with Mini Seismometer

The development of very small, versatile, rugged, low power, low noise, one or three-axis short-period seismometers is needed to monitor nuclear detonations. Specifications include total sensor size less than 1 cubic inch, low power consumption, low sensor self noise below the USGS Low Earth Noise Model, and dynamic range of at least 120 dB over a frequency band of 0.2 to 40 Hz. However, all commercially available high performance seismometers are large, heavy, and consume high power. Users therefore must choose between using instruments with significantly lower performance characteristics or reducing the size of the network. This situation is untenable, given the DOE responsibility to deploy detection systems for nuclear treaty monitoring and the current tight budget climate. This project will develop a new type of seismometer based on liquid inertial masses and electrochemical transducers. The approach involves the further miniaturization of a medium-period seismometer while maintaining low self noise and low power consumption. In Phase I, the concept was proven by building a working prototype, which was the size of a quarter. Phase II will improve sensor specifications and reduce the size. Commercial Applications and other Benefits as described by the awardee: The new seismometer should provide invaluable information on near-field and remote earthquakes, dynamic processes in the mantle, offshore oil exploration, and the behavior of structures subjected to seismic activity. With respect to the latter, engineers would be better able to understand the nonlinear behavior and failure modes of structures that are susceptible to collapse or significant damage, leading to improved designs and building codes.