A Dark Discharge Model of Earthquake Lightning
A model of dark discharge in the atmosphere before a large earthquake was proposed to elucidate the mechanism of generation of earthquake lightning and related electroatmospheric phenomena. Change in seismic stress releases piezo-compensating, bound charges due to changes in the piezoelectric polarization of quartz grains in granitic rocks, which produces an intense electric field at the fault zone. The excited or ionized molecules by free electrons accelerated under the electric field produce luminous phenomena in the atmosphere. Both Maxwell and Druyvesteyn distributions of the electron energy under the induced electric field were considered to estimate the rate of ionization and excitation of N2 and O2 molecules. An electric field and spatial distribution of earthquake lightning (EQL) were calculated based on the induced charges in the piezoelectric process which accompanies an earthquake. The intensity of emission from the excitation state, B3Πg of N2 molecule was estimated at 3×1020 photons/m3 close to the fault zone. A nucleus of precipitation might also be formed in a supercooled atmosphere leading to the appearance of earthquake fog and clouds.
Japanese Journal of Applied Physics
- Pub Date:
- September 1998