Geoscience Reference
In-Depth Information
POTENTIAL OF ELECTRIC FIELD (kV)
60
−
2
−
4
−
8
8
4
0
2
2
30
−
2
4
0
−
4
0
0
4
−
4
0
−
30
2
4
4
−
−
2
0
8
−
8
−
2
−
60
60
90
120
150
180
210
240
Magnetic longitude (deg . )
ELECTRIC FIELD (mV/m)
0.00
3.00
6.00
9.00
12.00
60
30
0
−
30
−
60
60
90
120
150
180
210
240
Magnetic longitude (deg . )
23.06.1986
11:00 UT
H=175 km
Fig. 4.13
Model-calculated electric field potential (
top
) and horizontal electric field vectors
(
bottom
) generated by the background and additional (seismogenic) sources for two earthquake
epicenters indicated by the markers
Namgaladze et al. (
2009a
,
b
) presented simulations in first approximation prov-
ing that NmF2 and TEC disturbances observed before earthquakes can be generated
by the vertical drift of the F2-region ionospheric plasma under the influence of a
zonal electric field of seismogenic origin. In case of TEC enhancements in mid-
latitudes and deepening of the equatorial anomaly trough, this field is directed to
the east and induces an electromagnetic drift of the plasma across the geomagnetic
field with velocity directed straight upward over the magnetic equator and upward
and poleward at mid-latitudes. The pattern of spatial distribution of the seismogenic
