EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Effects of Cracks and Fluids on Post-Seismic Healing

Alison Malcolm1, Somayeh Khajehpour Tadavani2, and Kristin Poduska2
Alison Malcolm et al.
  • 1Earth Sciences, Memorial University of Newfoundland, St John's, Canada (
  • 2Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St John's, Canada

It is now well established that large seismic events change the surrounding velocities, and that these velocities slowly recover over time.  Precisely which mechanisms control the recovery process are less well understood.  We present the results of laboratory experiments to better characterise what properties of the underlying material control the recovery process.  We do this by mixing two waves, one which perturbs the velocity of the sample (as an earthquake does in field data) and one which senses the change in velocity (as in changing noise correlations).  This is an inherently nonlinear experiment as we mix two waves and measure the effects of this wave mixing.  Within our experiments, we vary the properties of the samples to understand which are most important in controlling the nonlinear response.  We focus on two mechanisms.  The first is fractures and how changes in fracture properties change the nonlinear response.  The second is fluids, in particular the effect of low saturations on the nonlinear response.  By changing the fluids and fractures we can turn on and off the nonlinear mechanism, helping us to move toward a better understanding of the underlying mechanisms of these wave-wave interactions.

How to cite: Malcolm, A., Khajehpour Tadavani, S., and Poduska, K.: The Effects of Cracks and Fluids on Post-Seismic Healing, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9991,, 2020

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Presentation version 1 – uploaded on 30 Apr 2020
  • CC1: Comment on EGU2020-9991, Eric Larose, 01 May 2020

    excellent presentation, nice slides, thanks !

    • AC1: Reply to CC1, Alison Malcolm, 04 May 2020

      Thank you Eric!  Just let us know if you have any questions or suggestions!

  • AC2: Comment on EGU2020-9991, Alison Malcolm, 05 May 2020

    I will be in the splinter room from 3:45-4 pm after I visit some other rooms  

    If you would like to chat another time, please let me know here or

    • AC3: Reply to AC2, Alison Malcolm, 05 May 2020

      link to splinter room is not showing up, here it is again:

      • AC4: Reply to AC3, Alison Malcolm, 05 May 2020

        OK it is