PATC: CHEESE Advanced Training on HPC for Computational Seismology
21 October 2020

Place: Online

Date: 21-23 October 2020

Time: 9:00-17:00

Description

Are you interested in numerical wave simulations but feel like there are too many codes and methods out there and don’t know which option is right for you? Or perhaps you just want to refresh your knowledge and gain some practical experience with the different possibilities? Either way, this fully virtual workshop is for you!

During three full days on 21- 23 October 2020, you will receive introductory hands-on tutorials for ExaHyPE, Salvus, SeisSol, and SPECFEM3D, which are four different high-performance computational seismology software packages focused on waveform modeling and inversion. The workshop will provide you with an overview of their similarities, differences, and areas of applicability. Unique and in-depth half-day practicals will be provided for each package, with computational resources provided by HLRS. Participants will also be encouraged to present their own work and/or motivation as a one-minute lightning-talk during the wrap-up session of the workshop.

This training event is hosted by ChEESE, the Center of Excellence for Exascale in Solid Earth and supported by the ENERXICO project.

The organizers look forward to seeing you in October!

Target Audience

Researchers and students of all levels interested in augmenting their science with numerical waveform and dynamic rupture simulations as well as full-waveform inversion.

Learning outcomes

- A basic introduction to waveform physics modeling
- Hands-on experience with four different wave propagation codes

Prerequisites

- Basic knowledge of computational seismology (e.g., familiarity with the elastic wave equation)
- Basic knowledge of Python and Jupyter notebooks
- Optional: basic programming skills (C/C++, only for the ExaHyPE course module)

Course lecturers

SPECFEM3D - Vadim Monteiller (CNRS), Amandine Sergeant (CNRS)
SeisSol - Alice-Agnes Gabriel (LMU Munich), Duo Li (LMU Munich) , Thomas Ulrich (LMU Munich)
Salvus - Lion Krischer (ETH Zurich), Michael Afanasiev (ETH Zurich)
ExaHyPE - Leonhard Rannabauer (TUM), Anne Reinarz (TUM and Durham University)

Agenda

Day 1: 21 October 2020

- Introduction

- ExaHyPE

Day 2: 22 October 2020

- SeisSol

- SPECFEM3D

Day 3: 23 October 2020

- Salvus 

- Wrap up

About the codes

ExaHyPE (“An Exascale Hyperbolic PDE Engine” www.exahype.org ) is a software engine for solving systems of first-order hyperbolic partial differential equations. As an “engine”, ExaHyPE provides well-defined numerical schemes (high-order discontinuous Galerkin) on a fixed mesh infrastructure, but lets users formulate the specific PDE. In this course you will learn how to do so by implementing the acoustic wave equation within ExaHyPE. We will also provide an outlook to more complicated seismic modeling based on ExaHyPE.

SeisSol (www.seissol.org ) is a software package for simulating wave propagation and dynamic earthquake rupture based on the arbitrary high-order accurate derivative discontinuous Galerkin method (ADER-DG). SeisSol employs fully adaptive, unstructured tetrahedral meshes to combine geometrically complex 3D geological structures with  nonlinear rheologies and frictional failure across fault systems.

SPECFEM3D  The software package SPECFEM3D  (https://github.com/geodynamics/specfem3d) simulates seismic wave propagation at the local or regional scale and performs full-waveform inversion or adjoint tomography-based upon the spectral-element method. It can, for instance, model seismic waves propagating in sedimentary basins or any other regional geological model following earthquakes. SPECFEM3D  simulates wave propagation for acoustic (fluid), visco-elastic (solid), coupled acoustic/visco-elastic models in any type of conforming mesh of hexahedra (structured or not). In this course, you will learn how to set up with SPECFEM3D different kinds of simulations relevant in seismology (eg:  Basin, subduction zone, volcano, etc.). You will learn how to use the internal mesher MESHFEM3D and how to perform forward modeling. We will also give an overview of the inversion capabilities of the SPECFEM3D package (gradient or sensitivity kernels based on adjoint computation, full waveform inversion).
 
Salvus is a high-performance and scalable software package that solves full-waveform forward and inverse problems using the spectral-element method in both two and three dimensions. In this course we will give an interactive overview of the full-waveform inversion (FWI) process, including data processing, adjoint-source generation, gradient computation, workflow management, and nonlinear model updates. At the conclusion of the session, participants should have the knowledge required to set up and solve realistic FWI problems of their own. 

Fees

This course is free to all participants.

Registration

Please register here: https://regi.hlrs.de/2020/CHEESE/registration/reginit

*You will receive a confirmation email upon registration. 

*An HLRS User Admission Form will be sent after the registration deadline. Please make sure to fill this in and send it back in order to receive the Zoom link to the course.

*Registration deadline is on Sunday, 4 October 2020.