Yujiro Ogawa – författare

Accretionary prisms in convergent margins are natural laboratories for exploring initial orogenic processes and mountain building episodes.  They are also an important component of continental growth both vertically and laterally. Accretionary prisms are seismically highly active and their internal deformation via megathrusting and out-of-sequence faulting are a big concern for earthquake and tsunami damage in many coastal cities around the Pacific Rim. The geometries and structures of modern accretionary prisms have been well imaged seismically and through deep drilling projects of the Ocean Drilling Program (and recently IODP) during the last 15 years. Better understanding of the spatial distribution and temporal progression of accretionary prism deformation, structural and hydrologic evolution of the décollement zone (tectonic interface between the subducting slab and the upper plate), chemical gradients and fluid flow paths within accretionary prisms, contrasting stratigraphic and deformational framework along-strike in accretionary prisms, and the distribution and ecosystems of biological communities in accretionary prism settings is most important in interpreting the evolution of ancient complex sedimentary terrains and orogenic belts in terms of subduction-related processes.  This book is a collection of interdisciplinary papers documenting the geological, geophysical, geochemical, and paleontological features of modern accretionay prisms and trenches in the northwestern Pacific Ocean, based on many submersible dive cruises, ODP drilling projects, and geophysical surveys during the last 10 years. It also includes several papers presenting the results of systematic integrated studies of recent to ancient on-land accretionary prisms in comparison to modern analogues.  The individual chapters are data and image rich, providing a major resource of information and knowledge from these critical components of convergent margins forresearchers, faculty members, and graduate and undergraduate students.  As such, the book will be a major and unique contribution in the broad fields of global tectonics, geodynamics, marine geology and geophysics, and structural geology and sedimentology. 

Submarine mass movements represent major offshore geohazards due to their destructive and tsunami-generation potential.  This potential poses a threat to human life as well as to coastal, nearshore and offshore engineering structures. Recent examples of catastrophic submarine landslide events that affected human populations (including tsunamis) are numerous; e.g., Nice airport in 1979, Papua-New Guinea in 1998, Stromboli in 2002, Finneidfjord in 1996, and the 2006 and 2009 failures in the submarine cable network around Taiwan. The Great East Japan Earthquake in March 2011 also generated submarine landslides that may have amplified effects of the devastating tsunami. Given that 30% of the World’s population live within 60 km of the coast, the hazard posed by submarine landslides is expected to grow as global sea level rises. This elevated awareness of the need for better understanding of submarine landslides is coupled with great advances in submarine mapping, sampling and monitoring technologies. Laboratory analogue and numerical modeling capabilities have also developed significantly of late. Multibeam sonar, 3D seismic reflection, and remote and autonomous underwater vehicle technologies provide hitherto unparalleled imagery of the geology beneath the oceans, permitting investigation of submarine landslide deposits in great detail. Increased and new access to drilling, coring, in situ measurements and monitoring devices allows for ground-thruth of geophysical data and provides access to samples for geotechnical laboratory experiments and information on in situ strength and effective stress conditions of underwater slopes susceptible to fail. Great advances in numerical simulation techniques of submarine landslide kinematics and tsunami propagation, particularly since the 2004 Sumatra tsunami, have also lead to increased understanding and predictability of submarine landslide consequences.This volume consists of the latest scientificresearch by international experts in geological, geophysical, engineering and environmental aspects of submarine mass failure, focused on understanding the full spectrum of challenges presented by submarine mass movements and their consequences.