We have developed a 2-D/3-D arbitrary lagrangian-eulerian (ALE) finite-element code, SULEC, based on known techniques from literature. SULEC is successful in tackling many of the problems faced by numerical models of lithosphere and mantle processes, such as the combination of viscous, elastic, and plastic rheologies, the presence of a free surface, the contrast in viscosity between lithosphere and the underlying asthenosphere, and the occurrence of large deformations including viscous flow and offset on shear zones. The aim of our presentation is (1) to describe SULEC, and (2) to present a set of analytical and numerical benchmarks that we use to continuously test our code. SULEC solves the incompressible momentum equation coupled with the energy equation. It uses a structured mesh that is built of quadrilateral or brick elements that can vary in size in all dimensions, allowing to achieve high resolutions where required. The elements are either linear in velocity with constant pressure, or quadratic in velocity with linear pressure. An accurate pressure field is obtained through an iterative penalty (Uzawa) formulation. Material properties are carried on tracer particles that are advected through the Eulerian mesh. Shear elasticity is implemented following the approach of Moresi et al. [J. Comp. Phys. 184, 2003], brittle materials deform following a Drucker-Prager criterion, and viscous flow is by temperature- and pressure-dependent power-law creep. DOI: https://doi.org/10.21420/8Z3S-ZZ03 Cite model as: GNS Science. (2012). SULEC geodynamic finite-element code. GNS Science. https://doi.org/10.21420/8Z3S-ZZ03

A gravity map of the New Zealand region has been created from onshore observations and satellite altimetry. Onshore gravity is Bouguer Gravity Anomaly from the GNS database (http://dx.doi.org/10.21420/DRDW-VC72). Data were processed as described in the Terrestrial gravity section of McCubbine et al. (2017). Offshore gravity (and onshore outside of mainland NZ) is Free Air Gravity Anomaly Sandwell and Smith 1 minute land and ocean gravity grid v29 (2020).

A gravity map of the New Zealand region has been created from onshore observations and satellite altimetry. Onshore gravity is free-air Gravity Anomaly from the GNS database (http://dx.doi.org/10.21420/DRDW-VC72). Data were processed as described in the Terrestrial gravity section of McCubbine et al. (2017). Offshore gravity (and onshore outside of mainland NZ) is Free Air Gravity Anomaly Sandwell and Smith 1 minute land and ocean gravity grid v29 (2020).