THE ADANA EARTHQUAKE (TURKEY) - SEISMOTECTONIC FRAMEWORK, GEODYNAMIC PHENOMENA, IMPACT ON THE STRUCTURED ENVIRONMENT

The earthquake of Adana in Southern Turkey occurred on 27 June 1998 and caused extensive damage to the building environment. Approximately 150 people were killed and thousands were injured. Instrumental data give that the shock measured 6.2 (Ms) and was due to the reactivation of a sinistral strike-slip fault. The reported focal mechanism solution is in general accordance with the regional geotectonic setting, and was also confirmed by our observations on surficial seismic ruptures. Numerous ground fractures were located in and around Yakapinar. These were caused either by the seismic motion itself and/or were due to ground failure. Liquefaction and soil settlement were also observed in the same area, in the outcrops of the fluvial deposits of Ceyhan River, between Yakapinar and Abdioglu. Of prime interest is the damage caused by the earthquake to the inhabited areas within the meizoseismal area, and in particular in Adana, Ceyhan and smaller villages and settlements as Abdioglu, Yakapikaz, Misis, and so forth. The building environment is diverse, including various construction types. There were the older stone and brick masonry houses, together with modern ones; the former are usually small and highly vulnerable to earthquakes, while the latter have been built to meet certain earthquake-design standards. Every construction type suffered certain forms of damage, according to the quality of construction materials used, its age and the overall quality of construction.