Ð The geology of Lisbon is very diversi®ed, with a predominance of cretaceous rocks (basalt and limestone) in the western zone, while east and south it is covered by progressively thicker Tertiary deposits with diverse lithologies (sands, clays, silts, sandstones and limestones) and dierent geotechnical properties. Lisbon also contains several narrow long valleys, ®lled with thin alluvial deposits. A set of new geological pro®les was drawn, along the east±west direction, 500 meters spaced. These pro®les were based on the existing geological maps and complemented with new information collected from recent geotechnical boreholes. Theoretical modeling, using the Thomson±Haskell 1-D approach, was performed for 314 geological columns chosen from these pro®les according to a regular grid 500 meters long. The physical parameters were obtained from specialized literature, seismic experiments and laboratory tests. The results are presented as contour maps for the peak frequencies and for the corresponding ampli®cation factors. These results are compared with the microzonation map obtained by microtremor analysis and with the damage distribution observed in past earthquakes.

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The surface‐wave method using a multistation approach is a powerful field test as it is fast, robust and cost‐effective for geotechnical zonation of large areas. A case study is presented to illustrate the application of the method for the geotechnical characterization of an area located at Póvoa de Santa Iria, where Miocene bedrock is covered by thick Quaternary terraces and soft alluvial deposits. The results are analysed along with other relevant data: boreholes with standard penetration test data, resonant‐column tests on undisturbed samples and other available geological and geotechnical data.