Caprock leakage threshold ($\Delta \rho gh\cos \theta =\Delta p_{\mathrm{entry}}$)

A buoyant current beneath an overlying low-permeability cap can enter it when current overpressure exceeds the capillary entry threshold. The plateau criterion compares $\Delta \rho gh\cos \theta$ to that threshold. Cold and warm portions can have different depths and mobilities, giving distinct onset injection rates. These onset criteria do not determine the depleted current after leakage begins.