The Spitak
earthquake in 7 December 1988 wasn’t exclusive in the seismology
by its main characteristics and other peculiar features. It was
devastating tectonic earthquake of earth’s crust. On average at
least 15-20 such earthquakes occur on the Earth every year.
The Spitak earthquake is one of the most investigated earthquakes
in the world. The specialists had analyzed the main reasons of
the disaster and made steps on arranging the seismic risk assessment
and seismic protection on the bases of this analysis.
Like other strong earthquakes, the Spitak earthquake has its definite
features. It had started on December 7, 1988 at 7.41.22.7 GMT
(11.41.22.7 local time). The epicenter by the records of seismographs
has the following coordinates: latitude 40.92°N,
longitude 44.23°E.
The depth of the hypocenter, measured by various methods and means,
varies from 2.5km to 10-15km. It is natural as the earthquake
source as a spatial, geological body came out to the earth’s surface
at the Dzorashen-Halavar area and in subsurface it extended at
least about 15-20km depths. The magnitude of the earthquake was
7.0. The intensity at the epicenter was 10 value on MSK-64 intensity
scale. The Spitak earthquake belongs to the group of earthquakes
called “the whole cycle earthquake” i.e. there were foreshocks,
the earthquake and aftershocks.
The
earthquake hit 40 % of the territory of Armenia, densely populated
region with 1 ml people. The affected area, where the intensity
of the earthquake was > 8, involved 30002 km area. 21
towns and 342 villages were destructed, 514.000 people were left
without shelter, 20.000 people were injured and 12500 people were
hospitalized. Number of victims was about 25.000. Particularly
in Gyumri (15.000-17.000) and in Spitak (4000) number of victims
was more than anywhere else.
17% fund of dwellings were destroyed, the work of 170 industrial
companies were halted, the great losses were caused to villages
and agro industrial complexes as well as to the architectural,
historical and cultural monuments, 917 public buildings were destroyed.
The
unexpected disaster took unawares the organizations and agencies
that were called to work in emergency. The rescue activities were
systemized only two or three days later. From the first second
the earthquake strike, the population carried out restless rescuing
works. Anyhow the absence of their experience and sometimes the
lack of basic knowledge on actions in emergency caused real difficulties
for the efficiency of rescue operations. Even there were cases
when the public unawareness brought to life losses. Also there
was a need of rescue equipment.
With the efforts of population and the rescuers 45.000 dead or
alive people were brought out from the rubble and 12.5000 people
were hospitalized.
The
main reasons of the losses are various. Noteworthy among them
are as follows:
1. The seismic risk of the territory of Armenia was underestimated.
The intensity of 1988 earthquake was assessed in Spitak 10, in
Gyumri and Stephanavan 9 and in Vanadzor 8-9 value on MSK-64 intensity
scale.
2. The special governmental committee studying disaster subsequences
found out that definite mistakes in construction designing were
made.
3. The quality of construction was inadequate. The construction
technologies were violated and the materials didn’t correspond
to the standards.
4. Governmental bodies weren’t able to control the situation in
time and arrange the rescue works. Many structures weren’t ready
to resist the disaster.
Overwieving the main reasons of great losses, there is a need
to raise public awareness. It is necessary to learn from past
tragedy as the made mistakes are uncountable and the persons who
made those mistakes are inexcusably numerous.
