GeoWarp: Warped spatial processes for inferring subsea sediment properties
Conference
Format: IPS Abstract
Keywords: enviromental, geostatistics
Session: Invited Session 8A - Bayesian Models And Methods In Environmental Applications
Wednesday 4 December 1 p.m. - 2:30 p.m. (Australia/Adelaide)
Abstract
For offshore structures like wind turbines, subsea infrastructure, pipelines, and cables, it is crucial to quantify the properties of the seabed sediments at a proposed site. However, data collection offshore is costly, so analysis of the seabed sediments must be made from sparse measurements. Furthermore, the structure of the seabed sediments exhibits both nonstationarity and anisotropy.
To address these issues, we propose GeoWarp, a hierarchical spatial modeling framework for inferring the 3-D geotechnical properties of subsea sediments. GeoWarp decomposes the seabed properties into a region-wide vertical mean profile (modeled using B-splines), and a nonstationary 3-D spatial Gaussian process. Nonstationarity and anisotropy are accommodated by warping space in three dimensions and by allowing the process variance to change with depth.
We apply GeoWarp to measurements of the seabed made using cone penetrometer tests (CPTs) at six sites on the North West Shelf of Australia. We show that GeoWarp captures the complex spatial distribution of the sediment properties and, through cross-validation, show that its predictive performance is superior to other state-of-the-art methods.