Time-Varying Seismogenic Coulomb Electric Fields as a Probable Source for Pre-Earthquake Variation in the Ionospheric F2-Layer
The electric coupling between the lithosphere and the ionosphere is examined. The electric field is considered as a timevarying irregular vertical Coulomb field presumably produced on the Earth’s surface before an earthquake within its epicentral zone by some micro-processes in the lithosphere. It i...
Main Authors: | , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Korean Space Science Society (KSSS)
2017-12-01
|
Series: | Journal of Astronomy and Space Sciences |
Subjects: | |
Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2017/v34n4/OJOOBS_2017_v34n4_251.pdf |
Summary: | The electric coupling between the lithosphere and the ionosphere is examined. The electric field is considered as a timevarying irregular vertical Coulomb field presumably produced on the Earth’s surface before an earthquake within its epicentral zone by some micro-processes in the lithosphere. It is shown that the Fourier component of this electric field with a frequency of 500 Hz and a horizontal scale-size of 100 km produces in the nighttime ionosphere of high and middle latitudes a transverse electric field with a magnitude of ~20 mV/m if the peak value of the amplitude of this Fourier component is just 30 V/m. The time-varying vertical Coulomb field with a frequency of 500 Hz penetrates from the ground into the ionosphere by a factor of ~7×105 more efficient than a time independent vertical electrostatic field of the same scale size. The transverse electric field with amplitude of 20 mV/m will cause perturbations in the nighttime F region electron density through heating the F region plasma resulting in a reduction of the downward plasma flux from the protonosphere and an excitation of acoustic gravity waves. |
---|---|
ISSN: | 2093-5587 2093-1409 |