Gold Exploration, Groundwater, Geotechnical investigation, Image the ground and subsurface

What Is MASW?

Multichannel Analysis of Surface Waves (MASW) measures the shear-wave velocity (Vs) of the ground by analysing the dispersion of surface waves generated at the ground surface. The result is a 1D, 2D, or 3D profile of shear-wave velocity — directly reflecting the stiffness and dynamic properties of subsurface soils and rock.

The Science in Plain English

When you hit the ground with a sledgehammer, surface waves radiate outward. Different frequencies travel at different speeds depending on the stiffness of the soil — slower in soft material, faster in stiff or rocky ground. MASW records these waves using a line of geophones, then uses the frequency-velocity relationship to calculate shear-wave velocity with depth.

What Shear-Wave Velocity Tells You

Shear-wave velocity (Vs) is a direct measure of soil stiffness. Engineers use it for seismic site classification (Vs30), settlement estimation, rippability assessment, and detection of soft or voided zones. Most importantly, MASW gives you a continuous profile along a survey line — not just at a single borehole.

Case Study — Rock Depth for Pipe Jacking in Singapore

Before a pipe jacking operation in Singapore, the design team needed to know where shallow rock would be encountered along the alignment. A Groundsearch MASW survey identified depth to rock continuously — revealing two zones where bedrock was unexpectedly shallow, allowing TBM specification to be adjusted before excavation. MASW gives geotechnical teams a tool that bridges the gap between scattered boreholes at a fraction of the drilling cost.

Learn More About MASW Surveys