To increase the understanding of the physical properties of
precursor Seismic Electric Signals (SESs).
A detailed experimental study will be performed at three remote
sites in Greece, that have been found to be sensitive for
SES-collection. It will be accompanied by a laboratory
investigation of the emission of precursory phenomena.
Continuous measurements of the variations of the three components
of the electrotelluric field will be carried out at the following
three stations: One in North-western Greece (Ioannina area), one
in Northern Greece and one close to Athens. At each station,
twelve electric dipoles will operate with lengths ranging between
fifty meters and several kilometers. The horizontal components
of the earth's magnetic field will be also measured at two of
these stations. Furthermore radioelectric disturbances in the
atmosphere (but close to the surface of the earth) will be
continuously monitored at one of the stations. Seismic
measurements will also be made by installing one z-component
seismometer at each station. Also a detailed experimentation
will be carried out in Ioannina area in order to find in that
area four additional regions (stations) more or less equally
sensitive for SES collection to that of the already determined
Magnetic and gravity mapping of the three SES sensitive stations
will be made accompanied by a study of the geoelectric structure
involving deep and shallow electric soundings. Furthermore,
ELF-VLF multi-electrode array type MT-surveys close to two SES
sensitive stations will be carried out.
The laboratory experiments will investigate the form and other
properties of the electrical (and electromagnetic) precursors
emitted from rock samples subjected to an uniaxial stress
(with various rates). Acoustic emission will be also recorded at
various distances from the samples.
A data base will be created that will contain the SESs collected
during a continuous two year period. A study, of whether the
ratio of the SES vertical component in respect to the horizontal
ones is correlated with the epicentral area of the impending
earthquakes, will be made. The connection of the SES sensitivity
of a station to a specific geophysical property (e.g. gravity or
magnetic anomaly) and/or geological feature will be investigated.
The possible correlation between the SES- characteristics and the
earthquake source properties will be studied.
Funding SchemeCSC - Cost-sharing contracts
750 02 Uppsala