The sirch (Kerman, Iran) earthquake of 28 July 1981—A field investigation

On 28 July 1981 at 17:22 UTC, the Kerman province of southern Iran was shaken by the largest and the most destructive earthquake in its history. Its surface-wave magnitude was about 7.2. The epicenter of the earthquake was located about 45 km southeast of the city of Kerman, the capital of the Kerman province. The shock killed nearly 3,000 people, left more than 31,000 homeless, and destroyed virtually all buildings in the epicentral region within a radius of 30 km. The hardest hit place was the town of Sirch where about 2,000 people died out of a population of 3,500.Surface fractures were observed in several areas, and the earthquake was apparently associated with a fresh surface normal faulting. The maximum vertical displacement was about 1 m. The maximum width of the fracture was 0.5 m. Also, extensive landsliding and numerous rockfalls were observed within the area of maximum damage.Most houses in the epicentral area are of adobe construction, made of sundried clay brick walls, and heavy domed roofs or vaults with clay or mud mortar. Most casualties were due to the collapse of these adobe buildings. However, the performance of unreinforced or reinforced brick buildings, historical monuments, steel buildings, and other types of structures during the earthquake is also discussed in this paper.