A Global Evaluation of Lithology‐Dependent Marine Sediment Compaction Parameters and Their Uncertainties

Abstract Tectonic subsidence, sea level, and paleoclimate reconstructions using marine records rely on accurate decompaction of the sediment column. Over time, increased overburden pressure from burial decreases sediment porosity with depth. The porosity‐depth relationship is lithology‐dependent and can be represented by an exponential function determined by initial porosity at the seafloor and compaction decay length. While site‐specific compaction parameters are useful for most studies, these are often unrepresentative due to an insufficient number of measurements. Existing, commonly applied parameter estimates are based upon a handful of spatially restricted sites and lack meaningful uncertainty constraints. We compiled a global porosity data set consisting of 31,808 moisture and density measurements from 280 scientific ocean drilling sites visited during 60 Integrated Ocean Drilling Program and International Ocean Discovery Program (IODP) expeditions between 2009 and 2024. Using bootstrapping techniques, we resampled and fit porosity measurements 10,000 times using nonlinear least squares to obtain compaction parameters and uncertainties both globally and independently for sites in the Pacific, Atlantic, Indian, and Southern Oceans. Measurements from samples dominated by a single lithology (>75%) were used to obtain lithology‐dependent parameters. Average compaction behavior for marine sediments can be described with an initial porosity of 66.3±2.0% and a decay length of 1399±120 m. Our results confirm the lithology‐dependence of these parameters and indicate that sediment compaction behavior is consistent across ocean basins. These globally‐applicable parameters and uncertainties are a valuable resource for evaluating sediment decompaction and will enable error quantification in subsequent analyses of basin evolution and sedimentation.