The
earthquake event occured in the Grevena Prefecture of
Northern Greece at 11:47 local time on the 13th May 1995.
The mainshock, measuring 6.6 on the Richter scale, caused
over 100 million US dollars' worth of damage over an
area of 3,500 km2. There were fortunately
no deaths as the event occured on a Saturday when schools
and offices were empty.
Two ERS SAR scenes (16-Nov-93 and 09-Nov-95) and a 100m
resolution DEM were used to create a differential interferogram.
Due to the relatively long temporal separation and the
vegetated nature of the ground cover, image coherence
was not ideal, only 23% being the highest in the mountainous
regions where ground cover had not changed significantly.
The interferometric results were validated by ground-truth
collected by geodetic survey. A coseismic model derived
and interpolated from GPS measurements of trigonometric
survey monuments enabled prediction of the location of
the main fault (some 2km below the surface). This model
coincided extremely well with the differential interferogram,
which was then used to map the displacement field and
the fault system more accurately.
