Low velocity zones in the Earth crust and them petrophysical features
As low velocity zones result from temperature destruction of rocks uncompensated by pressure at 5-20 km depths, changes in T at these depths can lead to change in intensity of the thickness of these zones and rate of decrease in Vp within them. Crustal thermobaric zones are shown to increase, decrease and disappear depending on ∂T/∂Н, ∂Р/∂Н, λ, Т. Instability of the crustal thermobaric zones of low velocity result in their episodic occurrence in the crust and their vertical and horizontal migration depending on temperature fluctuations in the crust.