Near-Surface Investigation of Basalt Lava Flows using MASW Technique at Katraj Ghat Pune, India

Summary This study utilizes Multichannel Analysis of Surface Waves (MASW) to image the near- surface basalt units and characterize their seismic properties. Seismic survey was conducted in the Katraj Ghat region near Pune, located in the western Indian state of Maharashtra, where approximately 100 meters of volcanic stratigraphy is exposed. The results show that the shear wave velocities range from 0.15 km/s to 2.2 km/s, with notable low-velocity zones associated with weathered basalt units, such as the red bole layer. These low-velocity zones correlate well with field observations and shows relatively high porosity, which is significant for groundwater studies. Additionally, the low shear modulus of these units suggest weaker rock strength, making them important considerations in geotechnical applications for infrastructure projects. The MASW method proves effective in imaging the basalt layers and offers a powerful tool for seismic characterization of volcanic regions, with potential applications in groundwater management, hazard mitigation, and CO2 sequestration studies.