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Thomas Jordan

University of Southern California



Small, Patrick and Gill, David and Maechling, Philip J. and Taborda, Ricardo and Callaghan, Scott and Jordan, Thomas H. and Olsen, Kim B. and Ely, Geoffrey P. and Goulet, Christine (2017): The SCEC Unified Community Velocity Model Software Framework, Seismological Research Letters, GeoScienceWorld, Vol 88, Num 5
D. Roten, K. B. Olsen, S. M. Day, and Y. Cui (2017): Quantification of Fault-Zone Plasticity Effects with Spontaneous Rupture Simulations, Pure and Applied Geophysics, Springer Nature, Vol 174, Num 9, pp3369-3391


D. Roten, Y. Cui, K. Olsen, S. Day, K. Withers, W. Savran, and P. Wang (2016): High-Frequency Nonlinear Earthquake Simulations on Petascale Heterogeneous Supercomputers, IEEE Press, Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis (SC '16), pp82:1--82:12, Salt Lake City, Utah, U.S.A.
Ricardo Taborda, Shima Azizzadeh-Roodpish, Naeem Khoshnevis, and Keli Cheng (2016): Evaluation of the Southern California Seismic Velocity Models Through Simulation of Recorded Events, Geophys. J. Int., Oxford University Press (OUP), Vol 205, Num 3, pp1342--1364
W.H. Savran, and K.B. Olsen (2016): Model for Small-Scale Crustal Heterogeneity in Los Angeles Basin Based on Inversion of Sonic Log Data, Geophys. J. Int., Oxford University Press (OUP), Vol 205, Num 2, pp856--863


Yigit Isbiliroglu, Ricardo Taborda, and Jacobo Bielak (2015): Coupled Soil-Structure Interaction Effects of Building Clusters During Earthquakes, Earthquake Spectra, Earthquake Engineering Research Institute, Vol 31, Num 1, pp463--500


M. Böse, R. W. Graves, D. Gill, S. Callaghan, and P. J. Maechling (2014): CyberShake-Derived Ground-Motion Prediction Models for the Los Angeles Region with Application to Earthquake Early Warning, Geophysical Journal International, Oxford University Press (OUP), Vol 198, Num 3, pp1438--1457
D. Roten, K. B. Olsen, S. M. Day, Y. Cui, and D. Fäh (2014): Expected Seismic Shaking in Los Angeles Reduced by San Andreas Fault Zone Plasticity, Geophys. Res. Lett., Wiley-Blackwell, Vol 41, Num 8, pp2769--2777
Doriam Restrepo, and Jacobo Bielak (2014): Virtual Topography: A Fictitious Domain Approach for Analyzing Free-Surface Irregularities in Large-Scale Earthquake Ground Motion Simulation, International Journal for Numerical Methods in Engineering, Wiley-Blackwell, Vol 100, Num 7, pp504--533
Efecan Poyraz, Heming Xu, and Yifeng Cui (2014): Application-Specific I/O Optimizations on Petascale Supercomputers, Procedia Computer Science (14th Annual International conference on Computational Science, ICCS 2014), Elsevier BV, Vol 29, pp910--923, Cairns, Australia
En-Jui Lee, Po Chen, Thomas H. Jordan, Phillip B. Maechling, Marine A. M. Denolle, and Gregory C. Beroza (2014): Full-3-D Tomography for Crustal Structure in Southern California Based on the Scattering-Integral and the Adjoint-Wavefield Methods, J. Geophys. Res. Solid Earth, Wiley-Blackwell, Vol 119, Num 8, pp6421--6451
F. Wang, and T. H. Jordan (2014): Comparison of Probabilistic Seismic-Hazard Models Using Averaging-Based Factorization, Bulletin of the Seismological Society of America, Seismological Society of America (SSA), Vol 104, Num 3, pp1230--1257
Heming Xu, Yifeng Cui, James H. Dieterich, Keith Richards-Dinger, Efecan Poyraz, and Dong Ju Choi (2014): Aftershock Sequence Simulations Using Synthetic Earthquakes and Rate-State Seismicity Formulation, Earthquake Science, Springer Science + Business Media, Vol 27, Num 4, pp401--410


Jun Zhou, Yifeng Cui, Efecan Poyraz, Dong Ju Choi, and Clark C. Guest (2013): Multi-GPU Implementation of a 3D Finite Difference Time Domain Earthquake Code on Heterogeneous Supercomputers, Procedia Computer Science (13th annual International Conference on Computational Science, ICCS 2013), Elsevier BV, Vol 18, pp1255--1264, Barcelona, Spain
Ricardo Taborda, and Jacobo Bielak (2013): Ground-Motion Simulation and Validation of the 2008 Chino Hills, California, Earthquake, Bulletin of the Seismological Society of America, Seismological Society of America (SSA), Vol 103, Num 1, pp131--156
Y. Cui, A. Chourasia, Z. Shi, S. M. Day, P. J. Maechling, T. H. Jordan, E. Poyraz, K. B. Olsen, J. Zhou, K. Withers, S. Callaghan, J. Larkin, C. Guest, and D. Choi (2013): Physics-Based Seismic Hazard Analysis on Petascale Heterogeneous Supercomputers, Association for Computing Machinery (ACM), Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis (SC '13), Denver, Colorado, U.S.A.
Y. Cui, E. Poyraz, J. Zhou, S. Callaghan, P. Maechling, T.H. Jordan, L. Shih, and P. Chen (2013): Accelerating CyberShake Calculations on the XE6/XK7 Platform of Blue Waters, Institute of Electrical & Electronics Engineers (IEEE), 2013 Extreme Scaling Workshop (XSW 2013), Boulder, Colorado, U.S.A.
Zheqiang Shi, and Steven M. Day (2013): Rupture Dynamics and Ground Motion from 3-D Rough-Fault Simulations, J. Geophys. Res. Solid Earth, Wiley-Blackwell, Vol 118, Num 3, pp1122--1141


D. Roten, K. B. Olsen, and J. C. Pechmann (2012): 3D Simulations of M 7 Earthquakes on the Wasatch Fault, Utah, Part II: Broadband (0-10 Hz) Ground Motions and Nonlinear Soil Behavior, Bulletin of the Seismological Society of America, Seismological Society of America (SSA), Vol 102, Num 5, pp2008--2030
Y. Cui, K.B. Olsen, J. Zhou, P. Small, A. Chourasia, S.M. Day, P.J. Maechling, and T.H. Jordan (2012): Development and Optimizations of a SCEC Community Anelastic Wave Propagation Platform for Multicore Systems and GPU-Based Accelerators, Seismological Research Letters, Seismological Society of America (SSA), Vol 83, Num 2, pp396


En-Jui Lee, Po Chen, Thomas H. Jordan, and Liqiang Wang (2011): Rapid Full-Wave Centroid Moment Tensor (CMT) Inversion in a Three-Dimensional Earth Structure Model for Earthquakes in Southern California, Geophysical Journal International, Oxford University Press (OUP), Vol 186, Num 1, pp311--330


Philip J. Maechling (2017): Physics-Based Modeling of High-Frequency Ground Motions and Probabilistic Seismic Hazard Analysis, 2017 Blue Waters Annual Report, pp78-79


Thomas Jordan (2016): Physics-Based Strong Ground Motion Simulations, 2016 Blue Waters Annual Report, pp70-73


Thomas Jordan (2015): Earthquake System Science Research, 2015 Blue Waters Annual Report, pp44-46

Blue Waters Symposium a success

May 28, 2014

The symposium, held May 13-15 in Champaign, Ill., gathered many of the country’s leading supercomputer users to share what they have learned using Blue Waters and discuss the future of supercomputing. On May 13, 2014, Blue Waters supercomputer users and many of the NCSA staff who support their work converged in Champaign, Ill., for the second annual Blue Waters Symposium. The ensuing three days were filled with what many of them would later refer to as a wonderful variety of science talks and opportunities for networking and collaboration.


2015 Blue Waters Symposium highlights successes, looks to the future of supercomputing

May 29, 2015

The 2015 Blue Waters Symposium, held May 10-13 at Oregon's beautiful Sunriver Resort, brought together leaders in petascale computational science and engineering to share successes and methods. Around 130 attendees, many of whom were Blue Waters users and the NCSA staff who support their work, enjoyed presentations on computational advances in a range of research areas—including sub-atomic physics, weather, biology, astronomy, and many others—as well as keynotes from innovative thinkers and leaders in high-performance computing. Over the three days of the symposium, 58 science teams from across the country presented on their work on Blue Waters.


NSF awards time on Blue Waters to seven new projects

Oct 1, 2014

The National Science Foundation (NSF) has awarded 14 new allocations on the Blue Waters petascale supercomputer at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign. Seven of the awards are for new projects.


Los Angeles basin jiggles like big bowl of jelly in cutting-edge simulations

Aug 26, 2015

Earthquakes occur on a massive scale and often originate deep below the surface of the Earth, making them notoriously difficult to predict. The Southern California Earthquake Center (SCEC) and its lead scientist, Thomas Jordan, use massive computing power made possible by the National Science Foundation (NSF) to improve our understanding of earthquakes. In doing so, SCEC is helping to provide long-term earthquake forecasts and more accurate hazard assessments.


Preparing for the big one

Apr 21, 2010

The northern reaches of the San Andreas Fault have seen their share of major earthquakes in the last century. The 1906 San Francisco killed more than 3,000 people, and a 1989 quake near Santa Cruz postponed the World Series. The other end of the fault near Los Angeles, meanwhile, hasn't seen a major earthquake since 1680. But there is a high probability of a rupture over the next two decades. A team of more than 30 earthquake scientists, computer scientists, and other specialists are very interested in that next earthquake—what it might look like, what sort of damage it might cause, and what might be done to mitigate the damage. Led by the Southern California Earthquake Center (SCEC), they plan to use the Blue Waters sustained-petascale supercomputer at NCSA to model it.


Do the wave

Dec 4, 2014

Earthquake risk is a thorny subject scientifically and in society. In 2012, an Italian judge sentenced six Italian scientists and engineers and one government official to six years in prison for downplaying the risk of an impending earthquake in L’Aquila, Italy, in 2009. The charge was manslaughter. The judge held the scientists responsible for 29 of the 309 deaths because he said the scientists failed to properly analyze and explain the earthquake threat in the days leading up to the 6.3-magnitude quake. ... "It's incredible that scientists trying to do their job under the direction of a government agency have been convicted for criminal manslaughter," said geoscientist Tom Jordan to Science magazine when the verdict was handed down. "We know that the system for communicating risk before the L'Aquila earthquake was flawed, but this verdict will cast a pall over any attempt to improve it. I'm afraid that many scientists are learning to keep their mouths shut." Jordan is not one of those quiet scientists. At the Southern California Earthquake Center (SCEC) where Jordan is the lead scientist, the SCEC PressOn project aims to improve long-term earthquake prediction (on the decadal time scale) and modeling as a step toward more specific and accurate earthquake hazard assessments.


SCEC Improves Understanding of Earthquake Hazards with Supercomputers, Achieves Societal Impacts

Nov 18, 2015

Decision-makers from various sectors now have better knowledge to assess and mitigate earthquake risk owing to high-performance computing research by the Southern California Earthquake Center (SCEC), headquartered at the University of Southern California. On Thursday at the 2015 International Conference for High Performance Computing, Network Storage, and Analysis ("Supercomputer 2015") in Austin, Texas, SCEC Director Tom Jordan will present an invited talk on the societal impacts of SCEC's research and development in using supercomputers. "By using the nation's largest supercomputers, we can now forecast with more accuracy and detail the strong shaking that will come from large earthquakes in Southern California," stated Tom Jordan, Director of SCEC.


How will Blue Waters benefit science?

Jan 13, 2010

The Blue Waters supercomputer is one of the most powerful supercomputers in the world for open scientific research when it comes online at Illinois in 2011. How will scientists and engineers across the country use this tremendous resource? How will their research be advanced by a supercomputer that can do 1 quadrillion calculations every second? Many scientists are working now with the Blue Waters team so they are ready to use the massive sustained-petaflop supercomputer when it comes online in 2011. These teams will use Blue Waters to improve our understanding of everything from the Earth's climate to earthquakes.


10 ways advanced computing catalyzes science

Nov 18, 2015

When researchers need to compare complex new genomes, or map new regions of the Arctic in high-resolution detail, or detect signs of dark matter, or make sense of massive amounts of functional MRI data, they turn to the high-performance computing and data analysis systems supported by the National Science Foundation (NSF). High-performance computing (or HPC) enables discoveries in practically every field of science -- not just those typically associated with supercomputers like chemistry and physics, but also in the social sciences, life sciences and humanities. The Southern California Earthquake Center (SCEC) and its lead scientist Thomas Jordan use massive computing power to simulate the dynamics of earthquakes. In doing so, SCEC helps to provide long-term earthquake forecasts and more accurate hazard assessments.


Advances in Computational Research Transform Scientific Process and Discovery

Mar 25, 2013

Not every scientific discovery originates in the lab, or from the field. Scientists increasingly are turning to powerful new computers to perform calculations they couldn't do with earlier generation machines, and at breathtaking speed, resulting in groundbreaking computational insights across a range of research fields. .... Last October, NSF inaugurated Yellowstone, one of the world's most powerful computers, based at NCAR in Cheyenne, Wyo., and later this month will dedicate two additional supercomputers, Blue Waters, located at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, and Stampede, headquartered at the Texas Advanced Computing Center 9TACC) at The University of Texas at Austin. ... "The computer is excellent in permitting us to test a hypothesis," says Klaus Schulten, a professor of physics at the University of Illinois at Urbana-Champaign, who uses large-scale computing to study the molecular assembly of biological cells, most recently HIV, the virus that causes AIDS. "But if you want to test a hypothesis, you need to have a hypothesis."


San Diego State Researchers Advance 3D Earthquake Simulation

Jan 24, 2018

Working with data from the Lander earthquake that shook Southern California in 1992, a team of researchers from San Diego State University has advanced earthquake simulation capability by improving a widely-used wavefield simulation code and adapting it for improved 3D modeling and for use on high-end HPC systems. Their research delivered new insight into strike-slip earthquakes such as the Lander earthquake which was magnitude 7.3 and leveled homes, sparked fires, cracked roads and caused one death.


Amazing geoscience

Mar 28, 2018

Thomas Jordan and his team at the Southern California Earthquake Center are delivering seismic intelligence for better earthquake preparedness.