Exciting developments in earthquake science have benefited from new observations, improved computational technologies, and improved modeling capabilities. Designing realistic supercomputer simulation models for the complete earthquake generation process is a grand scientific challenge due to the complexity of phenomena and range of scales involved from microscopic to global.

The present volume - Part II - incorporates computational environment and algorithms, data assimilation and understanding, model applications and iSERVO. Topics covered range from iSERVO and QuakeSim: implementing the international solid earth research virtual observatory by integrating computational grid and geographical information web services; LURR (Load-Unload Response Ratio) described in six papers involving this promising earthquake forecasting model; pattern informatics and phase dynamics and their applications, which was also a highlight in the Workshop; computational algorithms, including continuum damage models and visualization and analysis of geophysical datasets; evolution of mantle material; the state vector approach; and assimilation of data such as geodetic data, GPS data, and seismicity and laboratory experimental data.

Exciting developments in earthquake science have benefited from new observations, improved computational technologies, and improved modeling capabilities. Designing realistic supercomputer simulation models for the complete earthquake generation process is a grand scientific challenge due to the complexity of phenomena and range of scales involved from microscopic to global.

The book is divided into two parts: The present volume - Part I - focuses on microscopic simulation, scaling physics, dynamic rapture and wave propagation, earthquake generation, cycle and seismic pattern. Topics covered range from numerical developments, rupture and gouge studies of the particle model, Liquefied Cracks and Rayleigh Wave Physics, studies of catastrophic failure and critical sensitivity, numerical and theoretical studies of crack propagation, developments in finite difference methods for modeling faults, long time scale simulation of interacting fault systems, modeling of crustal deformation, through to mantle convection.

Exciting developments in earthquake science have benefited from new observations, improved computational technologies, and improved modeling capabilities. Designing models of the earthquake generation process is a grand scientific challenge due to the complexity of phenomena and range of scales involved from microscopic to global. Such models provide powerful new tools for the study of earthquake precursory phenomena and the earthquake cycle.

Through workshops, collaborations and publications, the APEC Cooperation for Earthquake Simulations (ACES) aims to develop realistic supercomputer simulation models for the complete earthquake generation process, thus providing a "virtual laboratory" to probe earthquake behavior.

Part II of the book embraces dynamic rupture and wave propagation, computational environment and algorithms, data assimilation and understanding, and applications of models to earthquakes. This part also contains articles on the computational approaches and challenges of constructing earthquake models.

In the last decade of the 20th century, there has been great progress in the physics of earthquake generation; that is, the introduction of laboratory-based fault constitutive laws as a basic equation governing earthquake rupture, quantitative description of tectonic loading driven by plate motion, and a microscopic approach to study fault zone processes. The fault constitutive law plays the role of an interface between microscopic processes in fault zones and macroscopic processes of a fault system, and the plate motion connects diverse crustal activities with mantle dynamics. An ambitious challenge for us is to develop realistic computer simulation models for the complete earthquake process on the basis of microphysics in fault zones and macro-dynamics in the crust-mantle system. Recent advances in high performance computer technology and numerical simulation methodology are bringing this vision within reach. The book consists of two parts and presents a cross-section of cutting-edge research in the field of computational earthquake physics. Part I includes works on microphysics of rupture and fault constitutive laws, and dynamic rupture, wave propagation and strong ground motion. Part II covers earthquake cycles, crustal deformation, plate dynamics, and seismicity change and its physical interpretation. Topics covered in Part I range from the microscopic simulation and laboratory studies of rock fracture and the underlying mechanism for nucleation and catastrophic failure to the development of theoretical models of frictional behaviors of faults; as well as the simulation studies of dynamic rupture processes and seismic wave propagation in a 3-D heterogeneous medium, to the case studies of strong ground motions from the 1999 Chi-Chi earthquake and seismic hazard estimation for Cascadian subduction zone earthquakes.

In the last decade of the 20th century, there has been great progress in the physics of earthquake generation; that is, the introduction of laboratory-based fault constitutive laws as a basic equation governing earthquake rupture, quantitative description of tectonic loading driven by plate motion, and a microscopic approach to study fault zone processes. The fault constitutive law plays the role of an interface between microscopic processes in fault zones and macroscopic processes of a fault system, and the plate motion connects diverse crustal activities with mantle dynamics. An ambitious challenge for us is to develop realistic computer simulation models for the complete earthquake process on the basis of microphysics in fault zones and macro-dynamics in the crust-mantle system. Recent advances in high performance computer technology and numerical simulation methodology are bringing this vision within reach. The book consists of two parts and presents a cross-section of cutting-edge research in the field of computational earthquake physics. Part I includes works on microphysics of rupture and fault constitutive laws, and dynamic rupture, wave propagation and strong ground motion. Part II covers earthquake cycles, crustal deformation, plate dynamics, and seismicity change and its physical interpretation. Topics in Part II range from the 3-D simulations of earthquake generation cycles and interseismic crustal deformation associated with plate subduction to the development of new methods for analyzing geophysical and geodetical data and new simulation algorithms for large amplitude folding and mantle convection with viscoelastic/brittle lithosphere, as well as a theoretical study of accelerated seismic release on heterogeneous faults, simulation of long-range automaton models of earthquakes, and various approaches to earthquake predicition based on underlying physical and/or statistical models for seismicity change.

Vol. 157, 2000 spanning across disciplines and national boundaries gives cause for optimism. New participation in ACES to extend its existing synergies is welcomed. We wish to thank the scientific participants of The APEC Cooperation for Earthquake Simulation (ACES) and the contributors to this book. We express appreciation to the Australian, Chinese, Japanese and USA governments for supporting the establishment of ACES. We gratefully acknowledge funding support by the Australian government's Department of Industry, Science and Resources, The University of Queensland, Japan's Science and Technology Agency through its Research Organisation for Information Science and Technology, the Chinese Ministry of Science and Technology, and the National Science Foundation of China. We acknowledge with appreciation additional workshop sponsorship pro vided by SGI (Silicon Graphics). Special thanks to QUAKES team members (Tracy Paroz, David Place, Steffen Abe, Dion Weatherley and Steven Jaume) and Kim Olsen who provided assistance to the Editors. Peter Mora would also like to thank Evelyne Meier. REFERENCES I-st ACES Workshop Proceedings (1999), ed. Mora, P. (ACES, Brisbane, Australia, ISBN 1 86499 121 6), 554 pp. APEC Cooperation for Earthquake Simulation: http: //quakes. earth. uq. edu. au/ACES ACES Inaugural Workshop: http: //quakes. earth. uq. edu. au/ACES_ WS Raul Madariaga Peter Mora QUAKES Laboratoire de Geologie Department of Earth Sciences Ecole Normale Superieur The University of Queensland 24 Rue Lhomond 4072 Brisbane, Qld F-75231 Paris, Cedex 05 Australia France mora@earth. up. edu. au madariag@geologie. ens."