## 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.
Highlights

## COVID-19 lockdown leads to seismic noise “quiet period”

A new study by an international team of scientists found lockdown measures to stop the spread of COVID-19 led to a 50 per cent reduction in seismic noise around the world. The researchers, including Meghan Miller and Louis Moresi from ANU analysed datasets from over 300 seismic stations.

## Getting started: 60 seconds to Underworld

As the old truism states, the best way to learn is by doing. This guide can get you from zero to hero in 60 seconds - give or take.

## 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.

## Stress recovery in Underworld

Issues with intra-element discontinuities in PIC-FEMThe classical finite element method (FEM) has been widely used to simulate diverse problems in engineering. Unlike most engineering problems, geological simulations are dominated by emergence of geometrical structures due to the non-linear processes involved. For the structurally conforming FEM meshes, the large deformations result

## How to build Conda packages?

As mentioned, packages can be installed directly from our conda channel. You may however want to build your own package at some point in the future or you may want to fix some of ours by submitting a Pull Request on github (You are more welcome to do so...) The

## Getting started with Pull requests

Version control systems and online-communities such as Github have made contributing to the development of opensource software incredibly easy. That is assuming that people get over their initial fear of sharing their code!  In this short blog post I go through how to submit a pull request to one of

## 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.

## Stripy 2.0 released

Generating Voronoi diagrams and interpolating / smoothing with spline tensions are among a list of new features in Stripy 2.0

## Australian Seismometers in Schools - Noise monitoring dashboard

How we built a simple dashboard using Github actions with open source software and openly available (FAIR) data.

## Australian cities are quiet during lockdown. Earthquake scientists are making the most of it

Meghan S. Miller (ANU) Louis Moresi (ANU) Our responses to the COVID-19 pandemic have dramatically changed human activity all over the world. Sensitive instruments are detecting far less of the noise and vibration produced by humans in motion.

## Underworld publication news: Crustal thickness anomalies in stable continents.

The Underworld team would like to congratulate Bénédicte Cenki-Tok and co-authors at the University of Sydney and the University of Montpellier on their recent publication, B. Cenki-Tok, P.F. Rey, D. Arcay; Strain and retrogression partitioning explain long-term stability of crustal roots in stable continents. Geology doi: https://doi.org/

## 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

## An automated (zotero) bibliography in a webpage

How we added an auto-updating set of citations to underworld in our publications webpage. We need to curate all the publications that we can find that use the underworld geodynamics code and provide this information on our website. To avoid needless repetition, we take advantage of the fact that nearly

## 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_

## Alaska Moho Model (Reproducible research with containers)

Making your research reproducible means that you provide the entire workflow from data, through software and post-processing freely available. Not only can somebody repeat your experiments and verify them, they can build upon them. In lab-based disciplines, there are many further challenges, but in research that is predominantly based on

## Cite Underworld from Zenodo

Zenodo is a repository for immutable versions of software that are provided with a persistent DOI for the purposes of citation and reproducibility.   Underworld can be cited via a zenodo DOI. There is a master DOI for all releases (10.5281/zenodo.1436039) and releases after 2.6.0 are

## 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

## Underworld and Docker (part 2)

By the way, before you read this post, catch up with how we use docker by reading part 1 Docker allows us to distribute pre-built applications which are hosted in a virtual machine and are therefore platform independent. This simplifies things for us (only one platform we need to support)

## Underworld and Docker (part 1)

While huge improvements in usability have been achieved in Underworld2, the installation process is still unfortunately as painful as ever. This difficulty is in large part due to Underworld's numerous dependencies, and also the multiple platforms we try to support. Compounding this, the legacy of a individual user's machine often