World Bulletin/News Desk
Earthquakes pose a serious threat to Istanbul's historic monuments, an expert warned on Monday.
With its large number of historic monuments, and being located in one of the most seismically active regions in the world, the preservation of these monuments is clearly at risk, said Resat Oyguc, chairman of the Workshop on Seismic Risks of Historic Structures, which gave a conference on Monday.
"It is in well-known that earthquakes have caused significant damage to Istanbul's historic structures for centuries," Oyguc said. "The city is struck by a medium intensify earthquake every 50 years and experiencing a high earthquake every 300 years."
Istanbul is located on the North Anatolian Fault, one of the largest active faults in the world. Within the last 2000 years, more than 30 earthquakes with magnitudes larger than 7 have occured in the region.
The most recent one, Izmit earthquake, occurred in 1999: It had a magnitude of 7.4, and 18,000 people died in the quake. The epicenter was about 11 kilometers (7 miles) south of the city of Izmit, and some 80 kilometers (49.5 miles) away from Istanbul.
The Izmit earthquake not only damaged the historic monuments and structures but also hit many libraries and museums such as the Museum of Turkish and Islamic Arts, the Topkapi Palace Museum, Beyazit Library, Suleymaniye Library, the Dolmabahce Palace Museum and the Istanbul Painting and Sculpture Museum.
"Istanbul still falls behind many large cities in the world with regard to the preservation and the performance-based evaluation of its historic monuments." Oyguc said.
"Let's take example of the Hagia Sophia, one of the most well known historic monuments in the world as well as being one of the oldest historic structures of Istanbul.
"It is important to have access to exact engineering information in order to understand the structure itself as well as its vulnerabilities. Because accurate engineering is the first step to develop efficient conservation proposals for the transmission of the monument to future generations," Oyguc explained.
The Hagia Sophia mosque was built in the 6th century -- it was then a church. The building has suffered much from numerous earthquakes during its long history.
The building almost collapsed due to an earthquake in 557, just 20 years after it was built. Hagia Sophia was also exposed to another devastating earthquake in 1346. It is currently in the process of being restored.
Buildings like Hagia Sophia are retrofitted -- provided with new parts from stronger materials -- to protect them during earthquakes, but the process can damage the structures, according to Beste Alperat, from Faculty of Architecture of Middle East Technical University.
"However, retrofit practises may damage or destroy the significant features of such buildings," Alperat warns.
"Those who are working on the restoration must ensure that the architectural and engineering, cultural and social values of historic buildings are protected" she added.
Last Mod: 04 Kasım 2014, 00:09