This proposal seeks funding to develop a down-hole vertical strain sensor using an optical fiber approach. The proposed sensor will increase robustness by deploying only optical components down-bore ? keeping electronic components at the sediment-water or above-ground level. Additionally, the fiber will be deployed outside the borehole casing. The strainmeter will be deployed at the Piñon Flat Observatory (PFO) to compare data with existing strain-measuring instrument packages. A goal of this development is to extend the useful measurement frequency range. Strain is an integral part of understanding fundamental tectonic processes in the surface crust. An existing borehole at PFO will be used and data will be compared and validated against horizontal strain volume from existing sensors. The interferometric processing system has already been developed. Two main intellectual goals are sought: 1) to improve and evaluate the prototype instrument design and performance, and 2) to thoroughly test the assumption vertical strain can be related to horizontal strain through existing models. The management plan has the PIs and two other PI-level personnel receiving 0.5 month per year salary support. Two development techs and a graduate student will receive 3 month per year salary and tuition/fee support. A research project assistant will receive one month per year salary support. The remaining funds support supply and instrumentation acquisition and general logistical costs. The project will support a graduate student and results will directly impact the field of geodesy and has societal relevance in natural hazard monitoring.
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