Thorbecke, J.W.

His research started with the development of a new imaging method based on virtual focal points in the subsurface (called Common Focal Point technology). During this PhD project he started to write numerical algorithms to compute a seismic image in a reasonable compute time. At the end of this PhD he joined Cray and kept in close contact with the research carried out at the University of Delft. The combination between an efficient numerical implementation for new seismic methods is still the focus of his research at the TU-Delft and work at Cray.

Education:

October 1991 - October 1996 Ph.D., Delft University of Technology, Applied Physics: section Seismics and Acoustics.  (graduation January 1997).
January 1991 - August 1991 Leiden University, Philosophy,
September 1985 - January 1991 M.Sc., Delft University of Technology, Applied Earth Sciences: section Geophysics. (graduation January 1991).

Work

April 2009 - present, Cray (0.8) Pre-Sales - Application Engineer: . Benchmarking, optimisation and parallelization of scientific algorithms for Cray XC30 and CS300.
March 2002 - present, Delft University of Technology (0.2) Sr. Researcher: Marchenko, Seismic Interferometry, wave-equation modeling, Scientific computing, migration and inversion algorithms.
November 2008 - September 2009, Deltares Sr. Consultant: Optimisation and parallelization for hydrodynamics: Delft3Dflow.
March 2002 - June 2006, Cray, Application engineer: Optimized applications to Cray vector (X1E) and MPP (XT,XE).
May 2001 - February 2002, Jason Geosystems, Sr. Geoscientist: Parallelized sparse-spike inversion modules with MPI and PVM.
November 1996 - April 2001, Cray Research / Silicon Graphics / SGI, Geophysical applications engineer: Code optimisation, parallelization and porting to SGI/Cray hard- ware for geophysical, weather and scientific applications.

Expertise

Wavefield imaging and extrapolation, migration, modeling, interferometry, numerical algorithm design, parallelization, porting, writing and designing efficient algorithms for HPC.

Teaching

TG037: ‘Introduction to high performance computing’ GS credits: 3
TG136: ‘Programming with MPI’ GS credits: 2

Research

Senior researcher working on seismic interferometry, Marchenko algorithms, finite difference modeling, wavefield extrapolation, and geophysical algorithm design on Linux clusters.

• Parallel (MPI, and OpenMP and hybrid) programs written for Marchenko interation, Matrix eigenvalue/vector decomposition, seismic interferometry, multi dimensional deconvolution, least-squares inversion, and time and frequency correlation for continuously measured signals.
• Algorithm design, parallelization and optimization for large scale 4C passive seismic interferometry program running on MPP systems.
• 2D and 3D finite difference modeling for seismic interferometry.
• Project in 2008 on Seismic Interferometry sponsored by Statoil.
• Implemented 2D/3D recursive pre-stack depth migration algorithms parallelized with OpenMP and MPI.
• Research on reciprocity based relations between reflection and transmission operators.
• For the DELPHI consortium carried out research on matrix inversion of seismic data, local τ − p transform by means of a sparse non-linear conjugate gradient scheme, global inversion to Common Focal Point operators with CG, and multiple removal.
• Changed geophysical programs to run efficiently on a Linux cluster and implemented tools for seismic data processing.
• Reviewer for Geophysics, Geophysical Prospecting, Geophysical Journal International.
• Co-supervising MSc and PhD students.