MASW Seismic Surveys for Subsurface Site Characterization

 Multi-Channel Analysis of Surface Waves (MASW) is a seismic method used to characterize subsurface conditions by measuring shear-wave velocity (Vs) with depth. MASW provides continuous subsurface profiles without drilling, making it an efficient tool for geotechnical investigations, site characterization, seismic site classification, and early-stage project planning. 

 MASW surveys produce continuous two-dimensional subsurface profiles along survey alignments, allowing engineers to visualize changes in material stiffness and stratigraphy both with depth and laterally across a site. Unlike point measurements from borings, MASW subsurface profiling identifies variability between borings, detects soft zones, fill, and buried features, and improves confidence in overall site characterization. This continuous profiling capability helps reduce uncertainty early and supports more informed engineering and design decisions. 

• Shear-wave velocity (Vs) profiles with depth and along survey lines
• Identification of stiffness contrasts related to soil and rock properties
• Delineation of soft zones, fill, and zones of weathering or disturbance
• Mapping of depth to competent material or bedrock
• Detection of lateral changes in stratigraphy and subsurface conditions
• Identification of anomalous zones that may indicate faulting, fracturing, or voided ground
• Seismic site classification (Vs30) to support building design and code compliance (IBC / ASCE 7)
•  Rippability and excavation assessment

 MASW is widely used for site characterization because it provides rapid, continuous subsurface profiling while minimizing field time and logistical complexity. Compared to methods that require extensive layouts, dense electrode arrays, or intrusive access, MASW surveys can often deliver decision-ready subsurface information more efficiently. This allows engineers and owners to evaluate subsurface conditions earlier in the project lifecycle, reduce uncertainty, and manage risk at lower overall cost. MASW is particularly effective for projects where schedule, access, and budget are critical considerations.