Ipswich sits at the head of the Orwell estuary, roughly 11 metres above ordnance datum with underlying strata shaped by Cretaceous chalk, Crag sand, and London Clay — a layered sequence where velocity contrasts can catch out a standard borehole programme. Seismic tomography fills that gap, producing continuous P-wave velocity sections that reveal bedrock topography, fracture zones, and buried channels invisible to discrete sampling. The technique transmits a seismic pulse from a sledgehammer or weight-drop source and records arrival times across a geophone spread; MASW complements the dataset where shear-wave stiffness governs foundation response, and seismic refraction provides the baseline velocity model for tomographic inversion. Across the borough, from the Waterfront regeneration parcels to infrastructure corridors near the A14, the method reduces exploratory risk and anchors ground models in measured wave-speed data.
Seismic velocity sections resolve buried chalk pinnacles and silt-filled hollows that single boreholes routinely miss — a critical edge on Ipswich's variable drift geology.
