Low-Noise Borehole Triaxial Seismometer

72139-A low-noise, low-power broadband borehole seismometer is required for use in networks of seismic stations for monitoring underground nuclear explosions. This project will apply the latest technology from surface broadband instrumentation to the borehole application, leading to three prototype instruments that will be suitable for noise and stability testing at a seismically quiet site. In Phase I, research and theoretical modeling was conducted to demonstrate the feasiblity of using one instrument to cover the full bandwidth and noise targets. Phase II will develop two prototype borehole seismometers, plus one test unit designed for special noise tests. Extensive factory and field tests will be conducted to verify the seismic noise level and other parameters. A complete production drawing package will be produced. Commercial Applications and Other Benefits as described by awardee: A low cost, low-power, low-noise borehole triaxial seismometer should open the technology to more customers. For example, research programs are often prohibited from using borehole instruments because of the very high cost. A new surface instrument for very long period seismic signals could be a possible spin-off.