Karst subsidence in South-Central Apulia, Southern Italy

Abstract
Subsidence in the karst of Apulia (Southern Italy), one of the classical karst areas of Italy, is described in this paper. The carbonate rocks that make up the geological structure of the Apulia region are affected by subsidence, which is of different type and intensity depending upon geological, topographical, and hydrogeological conditions. In particular, we discriminate between inland subsidence and coastal subsidence. Inland subsidence is generally restricted to the presence of individual cavities, either empty or partly or totally filled with deposits produced by dissolution of soluble rocks underground. Locally, such subsidence can cause severe effects on anthropogenic structures above. The coastal plains of Apulia, particularly the southernmost part (Salento Peninsula), show interesting karst subsidence. Here the main feature is the development of compound sinks extending for several thousands of square metres, or the formation of individual, mostly circular, dolines along the coastline. Occurrence of one or the other of the above features seems to depend upon topographical conditions, and also upon their relationship with sea level oscillations.