Dix Seismo Lab Seminar

  What controls how big an earthquake can get? In this talk, I will present two special cases that may shed light on the process of earthquake growth and arrest: on-fault aftershocks and induced seismicity. I will show that while aftershocks can nucleate anywhere (on or off-fault), they only grow to be as large or larger than the mainshock if they nucleate outside the mainshock rupture. Stress decrease acts as a barrier to growth. For induced seismicity, the question is whether induced earthquakes are confined within the perturbation that triggered them. In this case, the answer appears to be no. While stress relaxation limits earthquake propagation, stress increase (on an already stressed tectonic fault network) does not.