Armenia
Earthquake of 1988
On December 7, 1988, at 11:41 a.m. local
time a magnitude 6.9 earthquake shook northwestern Armenia and was followed four minutes later by a magnitude 5.8
aftershock. Swarms of aftershocks, some as large as magnitude
5.0, continued for months in the area around Spitak.
The earthquakes hit an area 80 km in diameter comprising the towns of Leninakan, Spitak, Stepanavan,
and Kirovakan in the Armenian Soviet Socialist Republic.
The region is part of a broad seismic
zone stretching from Turkey to the Arabian
Sea near India. Here, the Arabian land mass is slowly colliding with the Eurasian
plate and thrusting up the Caucasus
Mountains in the north. The
earthquake occurred along a fairly small thrust fault running
northwest-southeast, apparently right under Spitak.
During the earthquake, the Spitak section to the
northeast of the fault rode up over the southwest side. Geologists have located
a 1.6 meter-high, 8-km long scarp just southeast of Spitak
where fault movement broke the surface.
The earthquake epicenter was located in
the Lesser Caucasus highlands, 80 km south of the main range of the Caucasus Mountains. Historically, this area has experienced damaging earthquakes.In 1899 and 1940 damaging earthquakes occurred
within 100 km of the 1988 epicenter. These events had magnitudes of 5.3 and 6.0
respectively. In 1920 a 6.2 magnitude earthquake that killed forty people
occurred north of Spitak. In 1926 an earthquake of
about magnitude 5.6 occurred 20 km southwest of Leninakan and reportedly caused more than 300 deaths and extensive
damage.
Despite its moderate size, the deaths and
damage that the December 1988 earthquake caused made it the largest earthquake
disaster since the 1976 magnitude 7.8 earthquake in Tangshan, China that killed more than 240,000 people. The Town of Spitak (population 25,000) was nearly leveled and more than half
of the structures in the City of Leninakan (population 250,000) were damaged or destroyed. Damage also
occurred in Stepanavan and Kirovakan
and other smaller cities. Direct economic losses were put at $14.2 billion (U.S.) at the United Nations official exchange rate. Twenty-five
thousand were killed and 15,000 were injured by the earthquake. In addition
517,000 people were made homeless. However, 15,000 people were rescued. Most of
these rescues were made within the first few hours following the disaster.
Many factors contributed to the magnitude
of the disaster, including freezing temperatures, time of day, soil conditions,
and inadequate building construction. A large number of medical facilities were
destroyed, killing eighty percent of the medical professionals. In this
earthquake both design deficiencies and flawed construction practices were
blamed for the large number of building collapses and resulting deaths. Many of
the modern multi-storied buildings did not survive. Soil conditions also
contributed to building failures. The high death rate may in part be attributed
to the way the buildings fell apart. When concrete floor panels about three
feet wide collapsed into compact rubble piles, little open space was left where
trapped people might survive. The proportion of survivors among people trapped
in the rubble of multi-storied buildings was approximately 3.5 times higher for
the ground floor than for higher floors. The collapse of a large number of
apartments which had many occupants on upper floors added to the number of
fatalities.
While
the earthquake exposed the flaws in the construction, it also exposed the good
in people around the world. The cooperation of international teams in rescue
efforts, the willingness of groups everywhere to contribute financial aid, and
especially the undaunted determination of the Armenians themselves to rebuild
their cities and their lives are worthy of commendation.
Source:
http://www.ngdc.noaa.gov/cgi-bin/seg/m2h?seg/haz_volume2.men+MAIN+MENU
Last edited 11/30/98
by Thuy Trinh and Andrew Beavers