1887

Abstract

Summary

It is generally difficult to obtain a reliable single-event source mechanism with a sparse surface array, mainly due to the typically low signal/noise ratio and poor azimuthal coverage. In this study, we propose an inversion procedure to estimate the focal mechanism of composite microseismic events - i.e., a set of events interpreted to share a common focal mechanism - recorded using a sparse surface network. Our method uses polarities of P-wave first motion together with Sh/P amplitude ratios. Sensitivity analysis using synthetic data indicates that reliable focal solutions can be obtained if both the amplification factor on Sh/P ratio is within the range of 0.25 ∼ 1.0, and > 50% polarities are correctly picked. We apply our approach to a set of 13 microseismic events recorded during hydraulic-fracture stimulation of the Marcellus Shale formation in West Virginia and Pennsylvania, USA. Similar to previous studies of this area, we obtain a focal mechanism comprised of northwest or northeast trending strike-slip faulting accompanied by a minor thrust-faulting component.

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/content/papers/10.3997/2214-4609.201700749
2017-06-12
2024-03-29
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References

  1. Got, J. L., Frechet, J. and Klein, F. W.
    [1994] Deep fault plane geometry inferred from multiplet relative relocation beneath the south flank of Kilauea. Journal of Geophysical Research, 99(B8), 15375–15386.
    [Google Scholar]
  2. Hicks, E. C., Bungum, H. and Lindholm, C. D.
    [2000] Stress inversion of earthquake focal mechanism solutions from onshore and offshore Norway. Norsk Geologisk Tidsskrift, 80, 235–250.
    [Google Scholar]
  3. Kamei, R., Nakata, N. and Lumley, D.
    [2015] Introduction to microseismic mechanisms. The Leading Edge, Special Section: Microseismic source mechanisms, 876–880.
    [Google Scholar]
  4. Lee, M., Davis, T. and Maxwell, S.
    [2014] Source mechanism characterization of microseismic data at Pouce Coupe Field, Alberta, Canada. Unconventional Resources Technology Conference, 15101517.
    [Google Scholar]
  5. Michael, A. J.
    [1987] Use of focal mechanism to determine stress: a control study. Journal of Geophysical Research, 92(B1), 357–368.
    [Google Scholar]
  6. Moorkamp, M., Jones, A. G. and Eaton, D. W.
    [2007] Joint inversion of teleseismic receiver functions and magnetotelluric data using a genetic algorithm: Are seismic velocities and electrical conductivities compatible?Geophysical Research Letter, 34, L16311.
    [Google Scholar]
  7. Sato, T., Kasahara, J., Taymaz, T., Ito, M., Kamimura, A., Hayakawa, T. and Tan, O.
    [2004] A study of microearthquake seismicity and focal mechanisms within the Sea of Marmara (NW Turkey) using ocean bottom seismometers (OBSs). Tectonophysics, 391, 303–314.
    [Google Scholar]
  8. Šílený, J., Hill, D. P., Eisner, L. and Cornet, F. H.
    [2009] Non-double-couple mechanisms of microearthquakes induced by hydraulic fracturing. Journal of Geophysical Research, 114(B8), B08307.
    [Google Scholar]
  9. Vavryčuk, V.
    [2015] Inversion for the composite moment tensor. Bulletin of the Seismological of Society of America, 105(6), 3024–3035.
    [Google Scholar]
  10. Zhang, H., Eaton, D. W., Li, G., Liu, Y. and Harrington, R. M.
    [2016] Discriminating induced seismicity from natural earthquakes using moment tensors and source spectra. Journal of Geophysical Research, 121(2), 972–993.
    [Google Scholar]
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