Seismic-Based Characterization of Marine Geohazards in the Offshore Region of Pakistan

The accurate identification of offshore geotechnical hazards is essential for the structural reliability and design optimization of offshore energy infrastructure in tectonically complex continental margins. The offshore domain, which hosts critical energy, pipeline, and foundation infrastructure, is often characterized by significant subsurface uncertainties tied to seabed instabilities, buried mass transport deposits (MTDs), and overpressure zones. To address these geotechnical risks, this study applies a high-resolution seismic stratigraphic interpretation framework to marine seismic data from the Offshore Indus Basin. This passive-margin yet tectonically reactive setting exhibits rapid sedimentation, fluid anomalies, slump scars, and folded turbidites. This study integrates sub-seabed seismic sequence stratigraphy, facies analysis, and structural mapping to delineate zones of high geotechnical vulnerability, such as under-consolidated muds, slump-prone structural packages, channel fill units, and detachment surfaces. Seismic facies and termination geometries were correlated with gas-prone layers, potential liquefiable units, and shear-weak zones. The results identify spatial hazard domains across three interpreted zones: (1) a shelf-to-slope transition zone with mixed stability and localized liquefaction risk; (2) collapsed and deformed slope sectors exhibiting rotated slumps and overpressure signatures; and (3) a deeply disturbed mass-transport complex with embedded gas zones and faulted strata. These mapped domains provide critical structural constraints for foundation siting, slope stabilization design, and long-term operational resilience in marine underground engineering. This study bridges seismic stratigraphy and geomechanical hazard assessment to support safer subsurface infrastructure design.