Shear traction is an equivalent concept to the shear stress. While the shear stress acting on faults is produced by the tectonic stress, the shear traction is produced by the solitary waves of couple stress (colored lines on the figure above). Tectonic waves cause daily oscillations of the shear traction in all tectonic zones worldwide and are responsible for triggering most of the earthquakes (colored circles on the figure above). Increased shear traction means an increased global triggering potential (PG), which is a quantitative measure of how likely the tectonic waves are to interact with unstable tectonic faults.
The most seismically active are slow tectonic waves with velocities below 200 km/day. Tectonic waves also have different Cosserat characteristic lengths, which is a concept equivalent to the wavelength in ordinary linear seismic waves. Our models calculate the waves with the characteristic lengths between 10.000 km (blue lines in the figure above) and 30.000 km (red lines in the figure above).
The shear traction can be calculated on a 1- or 0.1-degree scale based on the algorithms described by Žalohar (2018). The range of the normalized values of the shear traction is between 0 and 1.
- Žalohar, J., 2018. The Omega-Theory; A New Physics of Earthquakes. Elsevier, 558 pp.