Geoscience Reference
In-Depth Information
• observations for satellite orbits over earthquake sources at different latitudes;
• observations for satellite orbits above areas with light, moderate, strong, and
major
• earthquakes in different tectonic structures of the planet;
• angular distances of ∆λ≤25
◦
between the earthquake epicenter and the closest
point of the satellite orbit;
• seismic events in magnetically quiet days (the average geomagnetic activity
index K
p
≤ 5);
• exclusion of events at the beginning or in the end of the orbit when there are
calibrations and other operations that made the data unreliable;
• elimination of intervals with clear instrumental effects; and
• exclusion of orbits that do not contain terminator crossing.
The second task is to select the seismic data. We consider that it is necessary to take
in account the seismic situation 15 days before and after the monitoring for regions
with strong seismic activity and 5 days before and after the monitoring for relatively
quiet seismic regions. The earthquake data and related details for the same period are
based on USGS website.
DATA PROCESSING AND OBSERVATIONS OF THE QUASI-STATIC
ELECTRIC FIELD
New specialized software is used for the processing of experimental data about quasi-
static electric fields. We present our last results from observations of the quasi-static
electric field on board INTERCOSMOS-BULGARIA-1300 satellite in the upper ion-
osphere (h = 800-900 km) above earthquake sources in the Southern and Northern
Hemisphere at different latitudes. In the topic, the arrows indicate the moments when
the satellite passed at the closest distance ∆λ from the earthquake epicenter. The data
are presented as a function of the Universal time (UT), satellite altitude (ALT), the
geographic latitude and longitude (LAT, LONG), and the invariable latitude (Inv LAT).
South Atlantic Ocean
Five days before and after the passing of satellite (orbits 184, 198) and 5 days before
and after the passing of satellite (orbits 305, 347, 348, 403) the seismic manifesta-
tions in the region is shown in Figure 1a. Two events EQ
1
and EQ
46
(see Table 1) oc-
curred near the Scotia Sea in the southern Atlantic Ocean. The territory is a complex
area of marginal basins bordered by the Southern America and the Antarctic Plates.
The boundary motion between the cited two large plates represents predominately
left lateral strike-slip. The small Scotia microplate is twisted between the both plates
as a result of their horizontal movements (Earthquake Summary Poster, 2006). Two
earthquakes EQ
49
and EQ
60
with magnitudes M 5.1 occurred in the area of South Mid-
Atlantic Ridge (see Table 1). The ridge represents an oceanic rift that separates the
Southern American Plate from the African one in the South Atlantic Ocean. According
to plate tectonics, this ridge runs along a divergent boundary (The Mid-Atlantic Ridge,
2008). On the background of the trend in the quasi-statistic electric field we observe
