Proportional to depth? Do you mean the solid earth tides? The ocean loading tides can be ten times larger near the coast, and certainly do not extend down to the center of the Earth in a linear way.

You claim thermoelastic stresses can match tidal stresses in amplitude in your other recent post. So you're claiming thermoelastic stresses extend down to seismogenic depths, 10+ km? That's radically different than the few meters most have found. You must be postulating heat sources distributed throughout the Earth, rather than the effect of temperature at the surface, which can't spread one thousandth that far.

Maybe I'm missing the depths you define as "lower" and "upper" layers. Are we talking meters or kms?