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Earthquake Damage, Armenian SSR, December 7, 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 including the towns
of Leninakan, Stepanavan, Kirovakan, and Spitak (Republic of Armenia). 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 became 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 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. International
teams cooperated in rescue efforts and people around the world contributed financial
aid. With undaunted determination, Armenians began to rebuild their cities and their
lives.
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