Abstract
On June 23, 2001, an earthquake of magnitude 8.3 occurred at 1100 Kms south of Lima and about 250 Krns to the west of Arequipa . The four hundred year-old city of Arequipa, whose historical downtown was declared World Cultural Heritage by UNESCO, is known as the "White City" because most of the city is built with a volcanic stone called "sillar". This kind of stone exhibits a mostly white-gray color. Churches, monasteries and houses are built completely with this stone, which gives the city its characteristic appearance. The cathedral of Arequipa, located in the city's main square, is the most important neo-classical monument of Peru. It has a 100 m-long faqade and two towers at the top of the building having a height of 28 m. Due to the ef