# Underworld Code

Read about the underworld software and applications A collection of 18 posts

## Configuring and Installing PETSc for Underworld

The following is compatible with Ubuntu 20.04 under Windows 10/11 WSL 2 (Windows Subsystem for Linux). PETSc, the Portable, Extensible Toolkit for Scientific Computation is the main dependency required for building Underworld. In the following, I will describe my current workflow for configuring and installing PETSc on Linux.

## Underworld 2.11 Scaling

How does Underworld scale on a HPC? In this post we showcase how Underworld 2.11 scales across two of Australia's premiere HPC systems. Gadi - https://nci.org.au/our-systems/hpc-systemsMagnus - https://pawsey.org.au/systems/magnus/The reference model chosen for this scaling showcase is a extended

## How to install Underworld on Mac OSX (Apple Silicon M1)

The new generation of Apple Mac comes with the new Apple Silicon (M1) chip which has an Arm architecture (as opposed to the older generation that had i386 Intel processor). This brings all manner of troubles and requirements for the development of codes.

## Scaling in Underworld

To test scalability we run weak scaling tests on various HPC machines to check the numerical framework remains robust when pushing for higher fidelity models.

## Here comes Conda...

Sharing a workflow environment is also paramount if we want to make sure that reproducibility can be effectively tested. An environment management system such as conda allows us to do so.

## Underworld 2.10

Underworld 2.10 has dropped... kidding this is a benchmark model proposed by Schmalholz, 2011, A simple analytical solution for slab detachment.

## Underworld's lightweight cloud for online classrooms.

We built a cheap-and-cheerful solution with persistent storage and a binder-like access to notebooks in a repository that is aimed at serving a single classroom. The zero-to-server time is just a few minutes and there is minimal manual configuration.

## Underworld 2.9

The Underworld 2.9 release is available from Github, as a docker container and via zenodo (doi:10.5281/zenodo.3964957) it is also available through pip install for the first time

## JOSS publication - Underworld 2

A new paper by John Mansour and others has just been published in the Journal of Open Source Software. Mansour, J., Giordani, J., Moresi, L., Beucher, R., Kaluza, O.,  Velic,  M., Farrington, R., Quenette, S., Beall, A., 2020, Underworld2:  Python  Geodynamics Modelling for Desktop, HPC and Cloud, Journal of Open

## Underworld Release 2.8

Version 2.8 of Underworld has been released recently. As with all major releases, this release brings numerous new features, enhancements and bug fixes. A summary of changes may be found within the usual CHANGES.md file. As is also usually the case, numerous API changes have been necessary or

## Viscoelasticity in Underworld2

Viscoelastic materials exhibit the properies of both solids and liquids, with deformation rates dependent on both the viscous stress and elastic stress rate.  In a Maxwell viscoelastic material the strain rate $D$ is proportional to the sum of the stress $\tau$ and the stress rate $\dot\tau$, D_

## Craton Formation and the Onset of Plate Tectonics

(they don't make them like they used to ... ) Cratons are anomalously-strong regions of the continents that have largely resisted tectonic forces for billions of years. How such strong zones could be forged in a hot, low-viscosity, low stress,  early-Earth has been a long-standing puzzle for geologists. Adam Beall, Katie Cooper

## Modelling Drips and Delamination with Underworld

Modelling the relative time-scales of the Rayleigh-Taylor Instability and delamination, using Underworld With Adam Beall, Cardiff University. Why model sub-continental gravitational instabilities?Within the plate tectonics framework, continents are generally considered to have a much lower density than the asthenosphere below and therefore avoid the kind of recycling that the

## Using physical units in Underworld

Using physical units and how to appropriately scale a model is a top question users ask when beginning with Underworld. The equations Underworld solves are stated in a physically correct form, they remain valid as long as every material constant, geometry, time, etc., are expressed in the same system.  There

## Shear Bands with Dilatancy modelled with Underworld

In honour of Hans Mühlhaus' 70th birthday this month, here are some shear band simulations made with Underworld. We are investigating the role of dilatancy in the geometry of the shear bands for a box of material when a small trapdoor is opened. The extent to which large-scale deformation is

## Underworld2 Workshop at CIG 2016 Meeting

Underworld2 is a python-friendly version of the Underworld geodynamics code which provides a programmable and flexible front end to all the functionality of the code running in a parallel HPC environment. This gives signficant advantages to the user, with access to the power of python libraries for setup of complex