Application of Joint Inversion of Seismic and Gravity Data for Geological Characterization of Near Surface Zone

A comprehensive research on developing P-wave near-surface velocity models conducted during classic seismic data processing enabled not only a calculations of reliable values of static corrections, but also obtaining a detailed geological characterization of the shallow deposits and structures. Such a solution was possible to obtain by application of joint inversion of seismic refraction and gravity data and aimed to deal with complex geological and hydrogeological conditions of the Polish Lowlands. The presence of large thickness of glacial and post-glacial deposits typical for this region became an essential challenge for the presented experimental seismic study. This Quaternary formation comprises problematic for seismic acquisition unconsolidated material: gravel, sand and clay, which are additionally characterized by remarkable lateral and vertical lithological heterogeneity. In order to improve the quality of near-surface interpretation, it was inevitable to support the traditional interpretation methods, mainly seismic refraction tomography, with incorporation of the other, independent geophysical data. High-quality seismic data together with gravity anomaly gave an opportunity for the wider application of the joint inversion method to near-surface imaging for groundwater aquifers and mineral deposits prospection.