Damghan Earthquake
by On December 22, 856, an earthquake of magnitude 8 struck the city of Damghan, at that time the capital of the area we now know as Iran.
Typically, a flat roof is very heavy. It consists of some kind of boarding on which two feet of earth is laid. A flat roof is always preferred because it provides a cool place in which to sleep during the hot summer months and can also be used for drying crops. In mountain villages, a common sight in a country that has one third of its land area higher than ten thousand feet above sea level, houses are built with stones and held in place with a clay mortar. Where slopes are steep the roof of one house becomes the ground floor and outdoors of the next home above it. On lower elevations homes are built close together with very little space between them. When a home is damaged, the repair work rarely tries to make the place stronger and, therefore, better able to withstand the next earthquake.
The concept of making buildings as earthquake resistant as possible was unknown until recently. Heavy rainfall still destroys hundreds of homes in the course of a few hours. The idea of changing both the appear ance and shape of a home to make it better able to resist an earthquake began to appear for the first time in the second half of the twentieth century.
There is one group of Iranians who have no need to make their homes earthquake resistant-the nomadic tribes who need homes that can be dismantled and remounted in a short time as they move from place to place. Their homes are yurts and they are perfect examples of earthquake resistant homes. These structures are dome-shaped, circular, tents made of collapsible walls of willow poles, known as yurts. The roof of a yurt is domed and both roof and walls are covered with a kind of felt made from animal wool. Dried grass and strips of leather are used for holding the structure together. In summer, the felt sides are rolled up to admit air and, in winter, extra sheets of felt are added to the outside for warmth. The whole structure can be taken apart and reassembled in an hour, a vital feature for nomadic life. A yurt can provide a comfortable home for at least fifty years.
Liked it
