A terrain-following coordinate ocean circulation model is used tostudy different mechanisms of flow amplification at a shelf-edgesubmarine bank. The work is motivated by repeated hydrographicsurveys which revealed strong currents and anomalous densitystructures at Porcupine Bank, located at the shelf edge west ofIreland. Both steady and periodic forcing are investigated forweak, moderate and strong stratification. The resulting time-meanflows differ significantly in strength and structure and suggestthat flow rectification through resonant amplification of diurnaltrapped waves is the main process to explain the observed densityand current fields.