CitcomSVE: A Three‐Dimensional Finite Element Software Package for Modeling Planetary Mantle's Viscoelastic Deformation in Response to Surface and Tidal Loads. (4th October 2022)

• Record Type: Journal Article
• Authors: Zhong, Shijie; Kang, Kaixuan; A, Geruo; Qin, Chuan
• Is Part Of: Geochemistry, geophysics, geosystems. Volume 23:Number 10(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-04
• Subjects: numerical modeling -- glacial isostatic compensation -- tidal deformation -- parallel computing; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 550.5
• DOI: 10.1029/2022GC010359
• Languages: English
• ISSNs: 1525-2027

Abstract

Abstract: This article presents a comprehensive benchmark study for the newly updated and publicly available finite element code CitcomSVE for modeling dynamic deformation of a viscoelastic and incompressible planetary mantle in response to surface and tidal loading. A complete description of CitcomSVE's finite element formulation including calculations of the sea‐level change, polar wander, apparent center of mass motion, and removal of mantle net rotation is presented. The 3‐D displacements and displacement rates and the gravitational potential anomalies are solved with CitcomSVE for three benchmark problems using different spatial and temporal resolutions: (a) surface loading of single harmonics, (b) degree‐2 tidal loading, and (c) the ICE‐6G GIA model. The solutions are compared with semi‐analytical solutions for error analyses. The benchmark calculations demonstrate the accuracy and efficiency of CitcomSVE. For example, for a typical ICE‐6G GIA calculation with a 122‐ky glaciation‐deglaciation history, time increment of 100 years, and ∼50 km (or ∼0.5°) surface horizontal resolution, it takes ∼4.5 hr on 96 CPU cores to complete with about 1% and 5% errors for displacements and displacement rates, respectively. Error analyses shows that CitcomSVE achieves a second order accuracy, but the errors are insensitive to temporal resolution. CitcomSVE achieves the parallel computational efficiency >75% for using up to 6, 144 CPU cores on a parallel supercomputer. With its accuracy, computational efficiency and its open‐source public availability, CitcomSVE provides a powerful tool for modeling viscoelastic deformation of a planetary mantle with 3‐D mantle viscous and elastic structures in response to surface and tidal loading problems. Plain Language Summary: As high‐quality geodetic observations of Earth's surface deformation and gravity anomalies in response to tidal and surface loads (e.g., deglaciation) become readily available, and as powerful parallel supercomputers are more accessible, modeling dynamic deformation of the Earth's mantle with realistic 3‐D mantle viscoelastic rheology becomes both necessary and feasible. However, such modeling studies require an accurate, efficient and robust numerical modeling software package. This study presents a newly updated and publicly accessible finite element code CitcomSVE that can perform such modeling studies. This study describes the finite element formulation in CitcomSVE including calculations of other important geophysical processes such as sea level change, polar wander and apparent motion of Earth's center of mass. Three different benchmark calculations are performed at different spatial and temporal resolutions, and numerical errors are determined by comparing CitcomSVE solutions with semi‐analytical solutions. The benchmark calculations demonstrate that CitcomSVE is highly accurate and efficient and can be applied for modeling glacial isostatic compensation and tidal loading problems. Key Points: The newly updated and publicly available CitcomSVE is highly accurate and efficient for modeling GIA and tidal loading problems CitcomSVE achieves second order accuracy in spatial resolution but its solutions are insensitive to time resolution CitcomSVE achieves >75% parallel computing efficiency for using up to 6, 144 CPU cores