UC Santa Cruz

High-resolution seafloor and sub-surface data were acquired as part of a site survey in Iskenderun Bay, SE Turkey to characterize the geohazards at the location of the proposed drilling site. A 3km×3km geophysical study reveals a pockmark field which trends NE and NNE, similar to the trend of major fault systems in the area. The pockmarks, with an average diameter of 35m, reach their highest density in the northern part of the detailed survey area, with 13features/km2. Acoustic anomalies in the seismic records (acoustic turbidity, blanking, enhanced reflectors) below the proposed drilling site indicated potential shallow gas beneath it. The local seismic anomalies (amplitude and frequency) parallel to stratigraphy were assigned a low gas risk. As a result of the active neotectonics in the area, the pockmark field presented a potential hazard for drilling at the original location. The geohazard study resulted in moving the proposed drilling site eastward to an area of fewer pockmarks, less sub-surface seismic anomalies, and thus a location interpreted as a lower geohazard environment.