Seismic characterization of inland and coastal sabkhas using VP, VS, seismic anisotropy, and attenuation

Sabkhas represent abundant topographic environments along the Arabian Gulf and are increasingly relevant to hydrocarbon exploration and urban development. Their complex geological and hydrogeological settings significantly control near-surface seismic properties, influencing seismic velocity contrasts, attenuation ($${{Q}_{P}}^{-1}$$), and anisotropy. This study presents the first integrated application of P-wave velocity ($${V}_{P}$$), S-wave velocity ($${V}_{S}$$), $${{V}_{P}/V}_{S}$$ ratio, seismic anisotropy, and $${{Q}_{P}}^{-1}$$ attenuation analysis in sabkha environments, applied to the mature coastal sabkha of Abu Dhabi (CSAD) and the immature inland sabkha of Jayb Uwayyid (SJUW). Seismic refraction and multichannel analysis of surface waves (MASW) were used to obtain $${V}_{P}$$ and $${V}_{S}$$, compute the $${{V}_{P}/V}_{S}$$ ratio, and estimate seismic anisotropy and attenuation. Three distinctive zones were delineated in both sabkhas using the produced tomograms. The shallowest dry zone with $${V}_{P}$$​<428 m/s, $${V}_{S}$$ <261 m/s and ratios of 1-2 with a thickness of 1-5 m, respectively, a transition partially saturated zone with $${V}_{P}$$​<1900 m/s, $${V}_{S}$$ <760 m/s and ratios of 1.5-2.5 extend up to 8 m in CSAD and 6 m in SJUW, a fully saturated zone, extending below the partially saturated zone, is defined by higher velocities ($${V}_{P}$$>1900 m/s, $${V}_{S}$$>760 m/s) and ratios increasing toward ~2–4.5 with depth. $${{Q}_{P}}^{-1}$$ values reach up to 0.05 in both sabkhas, aligning with the hydrological zones, indicating fluid-related attenuation driven by seawater-brine interactions at CSAD and artesian upwelling at SJUW from continental brines. The uppermost parts of CSAD elevated velocities reflect a lithified hardground layer, while its elevated anisotropy marks its complex sedimentary and hydrological evolution. These results highlight the complexity of mature CSAD associated with elevated stratigraphy and hydrological conditions that affect the seismic signal.