Factors controlling natural subsidence in the Po Plain

Abstract

Understanding the causes and mechanisms of land subsidence is crucial, especially in densely populated coastal plains. In this work, we calculated subsidence rates (SR) in the Po coastal plain, averaged over the last 5.6 and 120 kyr, providing information about land movements on intermediate (103–105 years) time scales. The calculation of SR relied upon core-based correlation of two lagoon horizons over tens of km. Subsidence in the last 120 kyr appears to be controlled mainly by the location of buried tectonic structures, which in turn controlled sedimentation rates and location of highly compressible depositional facies. Numerical modelling shows that subsidence in the last 5.6 kyr is mainly due to compaction of the Late Pleistocene and Holocene deposits (uppermost 30 m).