ELECTROMAGNETIC FAULT FOR EARTHQUAKE LIGHTNING

A density of bound charges, q, which cancel piezoelectric polarization , appears at a fault zone upon the disappearance of piezoelectricity d ue to the release of seismic stress, sigma. q is described as dq/dt = -alpha d sigma/dt - q/epsilon rho, where alpha, epsilon and rho are th e piezoelectric coeflicient, the dielectric constant and the resistivi ty of the earth, respectively. A model of a fault with length 2a and d isplacement time tau gives q = [alpha sigma(o) epsilon rho tau(beta/a) /(tau-epsilon rho)l(e(-t/tau)-e(-t/epsilon rho)) using the velocity of s-waves, beta and the stress along the fault plane, sigma(o). The int ensity of earthquake lightning (EQL) and its spatial distribution are calculated based on the excitation of molecules by electrons accelerat ed under an electric field using the assumed q, taking atmospheric pol arization into account.