Yingcai Zheng, Professor at U. Houston and former MIT Earth Resources Laboratory researcher, presents "How to trigger earthquakes and volcanic eruptions by a propagating seismic wave" at ERL.

Live video of this talk will be available on ERL's Youtube Channel.

"In earthquake seismology, it is a well-established phenomenon that seismic waves excited by a large earthquake, after traveling thousands of kilometers, can trigger earthquakes/volcanic eruptions in regions where fluids are abundant. Since the incident wave stress perturbation is so small (~ kPa), it’s difficult to explain how the triggering can happen. Traditionally, people thought that the crust is in a critically stressed state and only a tiny stress perturbation is needed to trigger earthquakes. Zheng (2018) identified a pressure surge phenomenon (PSP) using numerical modeling. In the PSP, an incident wave can interact with a fluid-filled fracture and drive the fluid pressure in the fracture to > 2 orders of magnitude relative to the incident stress. This pressure magnification factor depends on frequency of the incident wave and fracture geometry. PSP may be the mechanism for the frequently observed earthquake triggering by passage of seismic waves. in this talk, I will discuss the PSP phenomenon and its implications and likely uses in many geophysical and geomechanical conditions."