Part II can be found here. Part III can be found here.
The Earthquake
On December 7th, 1988 at 11:41 local time, a large earthquake devastated Shirak and Lori Marzes in northwestern Armenia. The city of Spitak was reduced to rubble, while the cities of Gyumri (then Leninikan) and Vanadzor (then Kirovakan) sustained serious damage as well. Seismologists for USGS measured the earthquake as having a magnitude of 6.8 on the Richter scale.i For a contemporary comparison, the recent earthquake that occurred in January of 2010 in Haiti had a magnitude of 7.0.ii Because of the way magnitudes are calculated using base-10 logarithmic scale, each increase of whole number depicts an increase of approximately 31 times the energy released.iii The largest recored earthquake happened in 1960 in Chile and had a magnitude of 9.5.iv
The reason that Spitak was hit the hardest by the earthquake is because the epicenter was located along a small fault line directly under the city.vi Geologists have determined the focal point of the earthquake to be ten kilometers beneath the surface. The type of fault that broke the surface here is defined as a dip-slip fault by the United States Geological Service. In this instance, the fault is termed reverse because the rock above the fault moves up as opposed to down. A thrust fault is a reverse fault with a dip less than 45 degrees.vii A small flash animation demonstrating the movement of a thrust fault by USGS can be found here. Four minutes after the original shock, the area was assaulted with an aftershock with a magnitude of 5.8. Five days later, on December 12th, 1988, the Director of the Soviet Institute of the Physics of the Earth said at least 191 aftershocks were registered after the initial earthquake.viii
The direct economic cost of the earthquake was placed at $14.2 billion (US) based on the exchange rates of the day. Much of this cost occurred in Spitak which was close to being completely destroyed. Gyumri incurred a large portion of this cost as well. More than half of the buildings in Gyumri were destroyed or damaged. Stepanavan, Vanadzor, and other small cities and villages in the northwestern part of the country also sustained damage.ix Exact numbers according to USGS are, 314 buildings were destroyed, 641 needed demolishing, 1,264 needed strengthening and repairs. Of all the buildings, after the earthquake only 712 (less than twenty five percent) were inhabitable.x
This area of the world is no stranger to powerful movements of earth. In 893 an earthquake occurred that cost an estimated twenty thousand lives. In 1667 another eighty thousand were killed. In more recent history, devastating earthquakes have been recorded in 1894, 1899, 1914, 1920, and 1926. The movement of the Arabian Plate has also affected Georgia and Turkey. Turkey was hit with a 7.3 magnitude earthquake that is responsible for 5,000 deaths and another in 1983 which was registered as having a magnitude of 6.9 and killed 1,300 people.xi
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