The present volume contains a total of 23 papers centred on the research area of Seismic Assessment and Rehabilitation of Existing Buildings. This subject also forms the core of Project SfP977231, sponsored by the NATO Science for Peace Office and supported by the Scientific and Technical Research Council of Turkey [ TUBIT AK ]. Most of these papers were presented by the authors at a NATO Science for Peace Workshop held in Izmir on 13 - 14 May, 2003 and reflect a part of their latest work conducted within the general confines of the title of the NATO Project. Middle East Technical University, Ankara, Turkey serves as the hub of Project SfP977231 and coordinates research under the project with universities within Turkey, e. g. Istanbul Technical University and Kocaeli University, and with partner institutions in Greece and the Former Yugoslav Republic of Macedonia: A few articles have also been contributed by invited experts, who are all noted researchers in the field. Altogether, the contents of the volume deal with a vast array of problems in Seismic Assessment and Rehabilitation and cover a wide range of possible solutions, techniques and proposals. It is intended to touch upon many of these aspects separately below. Earthquakes constitute possibly the most widely spread and also the most feared of natural hazards. Recent earthquakes within the first six months of 2003, such as the Bingol Earthquake in Turkey and the Algerian earthquake, have caused both loss of life and severe damage to property.

This book will appeal to specialist engineers with enquiring minds and, in a broader sense, to all who live in buildings, especially those in a seismically active region. While the continual development of building codes permits the design of new construction to resist earthquake loads more effectively, a major problem is that buildings which may once have conformed to past seismic codes become structurally unacceptable according to today's codes and need upgrading or retrofitting'. Poor construction methods also result in buildings that do not conform to any codes. Existing vulnerable' buildings that require strengthening in earthquake-prone countries immensely outnumber all recent construction.
The health' of buildings thus requires assessment and rehabilitation. Seismic assessment ranges from the cataloguing of danger symptoms' in individual buildings to structural analyses involving finite element procedures and refined statistical analyses incorporating expert systems, stochastic processes and predictions from available databases. Structures have to be rendered fit for earthquakes, and this book goes a long way towards showing why and how, offering the results of cutting-edge research in the area and presenting innovative methods that enable system improvement while the structure remains in use.

What is the first thing that ordinary people, for whom journalists are the proxy, ask when they meet a seismologist? It is certainly nothing technical like "What was the stress drop of the last earthquake in the Imperial Valley?" It is a sim ple question, which nevertheless summarizes the real demands that society has for seismology. This question is "Can you predict earthquakes?" Regrettably, notwithstanding the feeling of omnipotence induced by modem technology, the answer at present is the very opposite of "Yes, of course". The primary motivation for the question "Can you predict earthquakes?" is practical. No other natural phenomenon has the tremendous destructive power of a large earthquake, a power which is rivaled only by a large scale war. An earth quake in a highly industrialized region is capable of adversely affecting the econ omy of the whole world for several years. But another motivation is cognitive. The aim of science is 'understanding' nature, and one of the best ways to show that we understand a phenomenon is the ability to make accurate predictions.

Geophysicists use seismic signals to image structures in the Earth's interior, to understand the mechanics of earthquake and volcanic sources, and to estimate their associated hazards. Keiiti Aki developed pioneering quantitative methods for extracting useful information from various portions of observed seismograms and applied these methods to many problems in the above fields. This volume honors Aki's contributions with review papers and results from recent applications by his former students and scientific associates pertaining to topics spawned by his work. Discussed subjects include analytical and numerical techniques for calculating dynamic rupture and radiated seismic waves, stochastic models used in engineering seismology, earthquake and volcanic source processes, seismic tomography, properties of lithospheric structures, analysis of scattered waves, and more. The volume will be useful to students and professional geophysicists alike.

This book provides the reader with a holistic approach to earthquake modeling and prediction. The lithosphere is studied as a hierarchical nonlinear dissipative system in which the predictability of earthquakes, aftershock activities and the variation of seismic activity are analyzed. More specialized models taking into account regional aspects are investigated. The reader will learn to pose the problem of earthquake prediction using a successive step-by-step approach, narrowing down the time interval, territory and magnitude range where a strong earthquake can be expected. The book is written for researchers in geophysics and applied mathematics but may also serve as an advanced textbook for graduate students wishing to enter the field.

This book deals with various theoretical and practical methods for real-time automatic signal processing in local (and regional) seismic networks and associated software developments, including extraction of small seismic signal from noisy observation by piecewise modeling and self-organizing state space modeling, determination of arrival time of S wave by locally multivariate stationary AT modeling, automatic interpretation of seismic signal by combining cumulativ sum and simulative annealing (CUSUM-SA), AR-filtering for local and teleseismic events, the currently high sensitivity seismic network running in Japan (Hi-net), PC-based computer package for automatic detection and location of earthquakes, real-time automatic seismic data-processing in seismic network running in eastern Sicily (Italy), the SIL (South Iceland Lowland) seismological data acquisition system and routine analysis in Iceland and Sweden.

In 1999, two earthquakes occurred in the Istanbul-Marmara region of Turkey and the Athens-Corinth region of Greece, and an increased risk of further events caused great concern among the earth science community. This book presents and discusses the latest results from studies of the Izmit-D zce and Athens earthquakes and assesses the data that are available and relevant to the geology, seismology, tectonics, geodesy and other fields related to earthquake studies and to evaluate earthquake hazard potential.

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.

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 1999, two earthquakes occurred in the Istanbul-Marmara region of Turkey and the Athens-Corinth region of Greece, and an increased risk of further events caused great concern among the earth science community. This book presents and discusses the latest results from studies of the Izmit-D zce and Athens earthquakes and assesses the data that are available and relevant to the geology, seismology, tectonics, geodesy and other fields related to earthquake studies and to evaluate earthquake hazard potential.

Vlastislav Cerveny Ivan Psencik Academy of Sciences of the Czech Charles University Republic Faculty of Mathematics & Physics Geophysical Institute Dep. of Geophysics Bocni II, 1401 Ke Karlovu 3 14131 Praha 4 12116 Praha 2 Czech Republic Czech Republic e-mail: ip@ig. cas. cz e-mail: vcerveny@seis. karlov. mff. cuni. cz (c) Birkhauser Verlag, Basel, 2002 Pure appl. geophys. 159 (2002) 1403-1417 I Pure and Applied Geophysics 0033-4553/02/081403-15 $ 1. 50 + 0. 20/0 Coupled Anisotropic Shear-wave Ray Tracing in Situations where Associated Slowness Sheets Are Almost Tangent l P. M. BAKKER Summary- For shear waves in anisotropic media a frequency-dependent transport equation is derived, which involves coupling of both shear modes if the slowness vector points in adirection for which the associated slowness surfaces are (almost) tangent. This is achieved by averaging the Hamiltonians for both uncoupled shear modes. No assumption on weak anisotropy is made, and the shear polarisation is perpendicular to the P-wave polarisation for the actual slowness direction instead of an isotropically approximated P-wave polarisation. These are the main differences compared with the so-called zero-order quasi-isotropic approach. Key words: Anisotropy, ray tracing, shear wave. J. Introduction Reliable modelling of polarisations for shear waves in anisotropic media is relevant in the context of imaging mode-converted (OBCjOBS) data in cases where not only poSY, but also poSH conversions take place. In such situations it may be necessary to use the polarisation direction for consistent continuation of the different wave modes and for appropriate imaging.

In September 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data center, and onsite inspections, to verify compliance. The problem of identifying small-magnitude banned nuclear tests and discriminating between such tests and the background of earthquakes and mining-related seismic events, is a challenging research problem. Because they emphasize CTBT verification research, the 12 papers in this special volume primarily addresses regional data recorded by a variety of arrays, broadband stations, and temporarily deployed stations. Nuclear explosions, earthquakes, mining-related explosions, mine collapses, single-charge and ripple-fired chemical explosions from Europe, Asia, North Africa, and North America are all studied. While the primary emphasis is on short-period, body-wave discriminants and associated source and path corrections, research that focuses on long-period data recorded at regional and teleseismic distances is also presented Hence, these papers demonstrate how event identification research in support of CTBT monitoring has expanded in recent years to include a wide variety of event types, data types, geographic regions and statistical techniques.

This new edition of the classic text by Aki and Richards has at last been updated throughout to systematically explain key concepts in seismology. Now in one volume, the book provides a unified treatment of seismological methods that will be of use to advanced students, seismologists, and scientists and engineers working in all areas of seismology.

requiring the adaptation of probabilistic maps to design ground motions; and (d) the generalization of design parameters to locations where there is little seismic history. Maximum displacements, velocities, and, based on the European Build ing Code EC8, design ground acceleration maps have thus been produced by ZivCic et al. for Slovenia, Marku ic et al. for Croatia, Bus et al. for Hungary, and Radulian et al. for Romania. The last two contributions in the volume are dedicated to studies of local site effects that could affect the microzonation of large urban areas. Moldoveanu et al. employed a technique based on the modal summation and finite dif ferences to calculate the expected ground motion in the capital city of Bucha rest due to large intermediate-depth Vrancea earthquakes. Their results outline that the presence of alluvial sediments and the possible variation of event scenario require the use of all three components of motion for a reliable determination of the seismic input. The study of Marmureanu et al., more limited in scope, offers a laboratory analysis of the attenuation effects for sur face layers. The authors confirm that seismic attenuation in sedimentary layers is a function of the strain levels induced by large earthquakes, and find that the quality factor is nearly constant over a relatively wide frequency range, between 7 and 100 Hz."

In many past and recent earthquakes it has been shown that the local conditions and, in particular, the local geology have a great influence on the observed seismic ground motion and, consequently, on the damage distribution in housing, industrial stock, and life-lines. Seismic microzoning is the usual procedure to have these local effects taken into account for engineering design and land-use planning, being a useful tool for earthquake risk mitigation. This volume presents a collection of papers mainly originated from a workshop on Seismic Microzoning, organized during the 23rd General Assembly of the European Geophysical Society (EGS) in Nice, France in April 1998. The workshop dealt with various geophysical tools for analysing the effects of the local soils of subsurface geology on seismic ground motion, namely the methods using experimental data such as microtremors, and the theoretical/numerical 1-D and 2-D modelling methods. Additional contributions discussing techniques for characterising soil properties, microzoning applications to several urban areas, and others were added to the volume to broaden this important topic.

This volume presents summaries of recent research results on the related subjects of source processes and explosion yield estimation, which are important elements of any treaty verification system. The term Source Processes, in the context of nuclear test monitoring, refers to a wide range of research topics. In a narrow definition, it describes the complex physical phenomena that are directly associated with a nuclear explosion, and the catastrophic deformation and transformation of the material surrounding the explosion. In a broader sense, it includes a host of topics related to the inference of explosion phenomena from seismic and other signals. A further widening of the definition includes the study and characterization of source processes of events other than nuclear, such as earthquakes and, in particular, mining explosions. This latter research is especially important relative to the question of identifying and discriminating nuclear explosions from other seismic events. Explosion Yield Estimation deals with the corresponding inverse problem of inferring explosion source characteristics through analyses of the various types of seismic signals produced by the explosion. This is a complex technical task which has been the focus of some of the most contentious treaty monitoring debates. The current compilation of eight articles on Source Processes and six articles on Explosion Yield Estimation gives a good representation of state-of-the-art research currently being conducted in the broad area of seismic source characterization in the context of nuclear test monitoring.

On September 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data center (IDC), and on-site inspections to verify compliance. Seismic methods play the lead role in monitoring the CTBT. This volume concentrates on the measurement and use of surface waves in monitoring the CTBT. Surface waves have three principal applications in CTBT monitoring: to help discriminate nuclear explosions from other sources of seismic energy, to provide mathematical characterizations of the seismic energy that emanates from seismic sources, and to be used as data in inversion for the seismic velocity structure of the crust and uppermost mantle for locating small seismic events regionally. The papers in this volume fall into two general categories: the development and/or application of methods to summarize information in surface waves, and the use of these summaries to advance the art of surface-wave identification, measurement, and source characterization. These papers cut across essentially all of the major applications of surface waves to monitoring the CTBT. This volume therefore provides a general introduction to the state of research in this area and should be useful as a guide for further exploration.

On September 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data center (IDC), and on-site inspections to verify compliance. Successful monitoring of a CTBT requires that we detect and identify all nuclear explosions. Since many events of concern will be too small to be detected teleseismically, this capability requires the use of regional-distance seismograms. The complexity of regional seismograms presents many technical challenges for a monitoring program. This issue focuses on problems associated with regional wave propagation through complex media. It includes papers that investigate regional variations of elastic and anelastic properties of Eurasia, the blockage of regional phases by sedimentary basins, methods for modeling regional wave propagation and for calibrating seismic wave paths in order to extract amplitude variations and source parameters. These papers illustrate the research and development necessary for acquiring an understanding of regional wave propagation which in turn provides the foundation for operational tools used to monitor a CTBT.

Vol. t59. 2002 J damaged zone on the rock mass. Collins el al. examine the benefits of employing small-scale microseismic and acoustic emission systems to investigate the temporal fracture mechanics of microcrack formation associated with a tunnel sealing experiment at the Underground Research Laboratory nuclear waste test site in Canada. They associate microseismic events with clusters of acoustic emissions and outline that both types of sources are generally characterized by deviatoric failure components. Using the same experimental setup, Hazzard el al. employed a bonded- particle model to simulate shear microfraclures induced by the lunnel excavation. Comparing Ihe modeling results with information provided by the moniloring of microseismicity and acoustic emissions, the authors identify similarities in both the presence of foreshocks associated with macro-slip events, and the pallerns of energy release during loading. Hildyard and Young allempt to model the seismic wave interaction with fractured rock surrounding underground openings, through exper- iments such as a rockbursl simulation, in situ events generating acoustic emissions, and laboratory fractures. Their results highlight that realistic wave modeling around openings requires the presence of a stress-dependent fracture stiffness coupling the surfaces of the fracture. Ultrasonic attenuation tomography and enhanced velocity tomography were studied by D~bski and Young for an earlier laboratory experiment of thennally induced fractures in granite.

In September 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data centre (IDC), and on-site inspections, to verify compliance. This volume contains research papers focusing on seismic ecent location in the CTBT context. The on-site inspection protocol of the treaty specifies a search area not to exceed 1000 square km. Much of the current research effort is therefore directed towards refining the accuracy of event location by including allowances for three-dimensional structure within the Earth. The aim is that the true location of each event will lie within the specified source zone regarding postulated location. The papers in this volume cover many aspects of seismic event location, including the development of algorithms suitable for use with three-dimensional models, allowances for regional structure, use of calibration events and source-specific station corrections. They provide a broad overview of the current international effort to improve seismic event location accuracy, and the editors hope that it will stimulate increased interest and further advances in this important field.

Volcanic eruptions are fascinating manifestations of the Earth's dynamic inte rior which has been cooling for the past several billion years. The planets of the solar system originated some 4.5 billion years ago from the same gas and dust cloud created by the big bang. Some of the gas collapsed by the gravitational force to form the Sun at the center, while the whirling disk of gas and dust around the Sun subsequently cooled and lumped together to form larger and larger lumps of materials or planetesimals. These planetesimals collided fre quently and violently and in the process liberated heat that melted the material in them. With time this material gradually cooled and formed the planets of the solar system. During the second half of the twentieth century the theory of plate tectonics of the Earth became established and demonstrated that our planet is covered with six large and many small plates of the lithosphere. These plates move over a highly viscous lower part of the Earth's upper mantle and contain the continental and oceanic crusts. The lower mantle extends below the upper mantle until it meets the core that is more than half the diameter of the entire globe (12,740 km). The inner core consists mostly of iron and its temperature is about 5000 kelvin, whereas the liquid outer core is turbulent, rotates faster than the mantle, consists primarily of iron, and is the source of the Earth's magnetic field.

PERTH Western Australia March 2000 Increasingly explorationists are seeking to find new ore deposits in poorly prospected areas, be they geographically remote, such as in the Arctic, or geologically remote, such as those under sedimentary cover. Modern prospecting techniques, including low-detection-level geochemistry and the use of advanced geophysical instrumentation have greatly assisted explorers but fundamental to any soundly based exploration program remains an understanding of the geological framework of ore deposits. This allows the development of deposit models on macroscopic and mesoscopic scales. This book by Dr. Franeo Pirajno draws on his extensive and wide global experience. To set the scene for a discussion of ore deposit generation Franeo details the Earths internal structures and mantle dynamics. He then explores the impact of mantle plumes on the crust and in particular their role in the production of magmatic environments, and in continental scale rifting. This includes a descriptive section on magmatic provinces around the globe, which highlights the importance of plumes. Any study of Earth processes needs to take into account the effects of extraterrestrial bombardment, and in particular the results from the impacts of large bolides. The effects of these impacts on the atmosphere and on life have now been recognised as profound. It is likely that the effect ofthese impacts on the Earth's crust is as equally profound.

There are few books and long review articles on water reservoir induced seismicity, mining induced seismicity and even on volcanic seismicity but the subjects of induced seismicity following fluid extraction and nuclear explosion and seismicity associated with tidal stress in Earth have not received significant attention though there are research papers in relevant literature. Thus an attempt has been made to discuss all the known forms of induced seismicity in the present book and to bring out common features of the different phenomena causing induced seismicity. The book has six main chapters namely 2, 3, 4, 5, 6 and 7, the first and last chapters, namely 1 and 8 being introduction and overview of all forms of induced seismicity. Material in Chapters 2 and 3 is rather recent though water reservoirs and petroleum extraction processes have been in existence over many decades. But, literature on chapters 4 and 5 is available since last one century or so as volcanic process and mining operation affect nearby human habitation and mining severely due to induced seismicity associated with mining in particular. However, literature on possible induced seismicity due to tidal stress is fairly old, the same following nuclear explosion is naturally recent.

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."