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 at least 120 dB over a frequency band of 0.2 to 40 Hz. However, all commercially-available high performance seismometers are large and 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 is an untenable situation, given the DOE responsibility to deploy detection systems for nuclear treaty monitoring and the current tight budget climate. The solution of the problem involves the design of 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 with low-power consumption. Commercial Applications and other Benefits as described by the awardee: In addition to the application for nonproliferation, the new seismometer would 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. Data from structures that are susceptible to collapse, or to significant damage would enable engineers to better understand their nonlinear behavior and failure modes. In turn, this understanding would lead in turn to improved designs and building codes, and the identification of those structures that need to be reinforced.