2024 VBRc Virtual Workshop Materials

This repository contains example code and exercises for the 2024 VBRc workshop (July 15-18 2024).

Workshop Recordings

The talks and tutorials were recorded and are available for viewing at the following links:

• Day 1 - Welcome to the VBRc Virtual Workshop (5 minutes)
• Day 1 - Introducing the VBRc (18 minutes)
• Day 1 - Tutorial: Getting Started with the VBRc (77 minutes)
• Day 1 - Tutorial: Introduction to Anelasticity with the VBRc (74 minutes)
• Day 2 - Joseph Byrnes - Connecting the Upper Mantle to Volcanoes in the Western United States (52 minutes)
• Day 2 - Tutorial: Interpreting Seismic Observations with the VBRc (52 minutes)
• Day 3 - Josh Russell - Unlocking Pacific upper mantle state using the VBRc: What are the roles of mantle grain size and melt? (50 minutes)
• Day 3 - Lightning Talks(60 minutes)
• Day 3 - Harriet Lau & Chris Havlin - Introducing Apparent Viscosity (41 minutes)
• Day 3 - Harriet Lau - Inference of the Timescale-Dependent Apparent Viscosity Structure in the Upper Mantle Beneath Greenland (28 minutes)
• Day 4 - Chris Havlin - Open source, the VBRc and YOU! (70 minutes)
• Day 4 - Tutorial: Setting up your VBRc development environment and submitting pull requests (54 minutes)

Lightning talk session recording

The full lightning talk session recording is available at this link. To jump to a particular presentation:

• Oliver Boyd - The USGS National Crustal Model for Seismic Hazard Studies: link
• Ivan Rojas-Churkovic - Kinematic rupture parameters of two Earthquakes in southern Peru (2013, 2018): link
• Mingqi Liu - The effect of grain size reduction on the origin of the mid-lithospheric discontinuity link
• Leif Karlstrom - New perspectives on viscoelastic deformation and opportunities for interpretation of ground deformation timeseries: link
• Eva Golos - On the use of geophysical interpretive toolkits as mantle thermometers: link
• Keneni Godana - Exploring Mid-Ocean Ridge Dynamics Using VBRc: link
• Christian Salas - Seismic Body-Wave Velocity and Attenuation Tomography of the Crust and Upper Mantle Beneath Alaska: link
• Sam Ofori - Elecrical Conductivity (EC) and the VBRc: link
• Walid Ben Mansour - 3-D thermochemical tomography from probabilistic joint inversion of multi-observable geophysical datasets: link

Workshop Documents

Workshop documents are available in the public google drive including:

• Workshop schedule
• Presentation slides

Archived versions of the presentations are also available at https://doi.org/10.5281/zenodo.12823718

Repository Description

This repository contains starter code used during tutorials in the 2024 VBRc Virtual Workshop. It is organized by the day of the workshop:

Day 1 (day_1/) - Basic Usage of the VBRc

This directory contains scripts that introduce how the run the VBRc. The first four scripts are designed to be very simple entry points into running calculations:

• ex_01_basic_usage.m - setting up and running a calculation
• ex_02_adjusting_parameters.m - understanding how method parameters are set and modified
• ex_03_deformation_mech_map.m - using the VBRc to build a deformation mechanism map for steady state creep
• ex_04_asthenosphere_properties.m - calculating some mechanical properties at asthenospheric conditions

The final script, ex_05_anelastic_methods_melt.m, introduces the anelastic methods available in the VBRc and compares dependence on melt fraction between anelastic methods.

Day 2 (day_2/) - Interpreting Seismic Observations with the VBRc

This directory contains scripts and functions related to using the VBRc for interpreting seismic observations.

• ex_01_bayes_inference_0d.m : builds a 2D VBRc look up table and runs a gridded bayesian inference.
• ex_03_bayes_0d_mcmc_Tonly.m : a single-parameter (Temperature) markov-chain monte carlo (mcmc) inversion with Metropolis-Hastings (MH) sampling.

The final two scripts use a parametrized 1-d temerpature model to introduce depth-dependent simulation.

• ex_04_plot_model.m - calculates and plots the 1d model
• ex_05_bayes_1d_mcmc.m - ex_01_bayes_inference_0d.m modified to use the parametrized 1d model.

Note that each of these scripts have corresponding subdirectories in day_2 that include a number of helper functions.

Day 3 (day_3/) - Mechanical properties across very broad timescales

This directory contains an example of using the new theoretical andrade model in the VBRc (ex_1_generic_andrade.m) and an example of calculating the complex viscosity (ex_2_complex_viscosity.m).

Requirements

The code here requires the VBRc (https://vbr-calc.github.io/vbr/).