Studies of convection in geophysical flows constitute an advanced and rapidly developing area of research that is relevant to problems of the natural environment. During the last decade, significant progress has been achieved in the field as a result of both experimental studies and numerical modelling. This led to the principal revision of the widely held view on buoyancy-driven turbulent flows comprising an organised mean component with superimposed chaotic turbulence. An intermediate type of motion, represented by coherent structures, has been found to play a key role in geophysical boundary layers and in larger scale atmospheric and hydrospheric circulations driven by buoyant forcing. New aspects of the interaction between convective motions and rotation have recently been discovered and investigated. Extensive experimental data have also been collected on the role of convection in cloud dynamics and microphysics. New theoretical concepts and approaches have been outlined regarding scaling and parameterization of physical processes in buoyancy-driven geophysical flows. The book summarizes interdisciplinary studies of buoyancy effects in different media (atmosphere and hydrosphere) over a wide range of scales (small scale phenomena in unstably stratified and convectively mixed layers to deep convection in the atmosphere and ocean), by different research methods (field measurements, laboratory simulations, numerical modelling), and within a variety of application areas (dispersion of pollutants, weather forecasting, hazardous phenomena associated with buoyant forcing).

This book presents a historical perspective on plate tectonics. In doing so it discusses the foundations of rigid plate tectonics and the limitations of this approach. This classic approach explains the data at a level of 95 % precision. The authors explain data anomalies as a result of the discrepancies between spatial geodetical data and rigid kinematics in oceans. Data and its interpretation from various disciplines are pulled together in this book.

This book is devoted to the quantitative physical modeling of subduction and subduction-related processes. It presents a coherent description of the modeling method (including similarity criteria, and a novel applied experimental technique), results from model experiments, theoretical analysis of results on the basis of continuum mechanics, and their geodynamic interpretation. Subduction is modeled in general as well as applied to particular regions using both 2-D and 3-D approaches, with both slab-push and slab-pull driving forces. The modeling covers all stages from subduction initiation to death', different regimes of subduction producing back arc extension and compression, blocking of subduction and jumps of subduction zone, arc-continent collision and continental subduction. This work is for geologists and geophysicists interested in geodynamics of the convergent plate boundaries and in mechanics of the lithosphere.

Marine protected areas (MPAs) have an important role in marine conserva tion programmes around the world. Although most have been established relatively recently when compared with protected areas on land, there is considerable expertise on their identification, setting up and management. Some techniques have been adapted from those used on land. Others are novel, and unique to marine conservation. The chapters in this book give an insight into this fast developing field where experiment and innovation work alongside techniques which have been tried and tested. The guiding princi ples behind key stages in the setting up and management of MP As are described, and case studies illustrate how they have worked. While it is most encouraging to read about the successes, the case studies also point to difficulties which have been encountered. Not all of the examples are new or recent but, together, they illustrate what is happening in this field.

In recent years, research on acoustic remote sensing of the ocean has evolved considerably, especially in studying complex physical and biological processes in shallow water environments. To review the state of the art, an international workshop was held at Carvoeiro, Portugal, in March 1999, bringing together leading international researchers in the field. In contrast to much of the recent theoretical work, emphasis was placed on the experimental validation of the techniques. This volume, based on presentations at this workshop, summarizes a range of diverse and innovative applications. The invited contributions explore the use of acoustics to measure bottom properties and morphology, as well as to probe buried objects within the sediment. Within the water column, sound is applied to imaging of oceanographic features such as currents and tides or monitoring of marine life. Another key theme is the use of sound to solve geometric inverse problems for precise tracking of undersea vehicles. Audience: This volume should be useful both to the novice seeking an introduction to the field and to advanced researchers interested in the latest developments in acoustic sensing of the ocean environment. The workshop was sponsored by the Fundacao para a Ciecia e a Tecnologia (Portuguese Foundation for Science and Technology).

This volume reflects the present state of the study of the Mediterranean as carried out by the Italian scientific community. The multidisciplinary character of the papers creates different "transversal" reading and clustering possibilities that the informed reader is free to design and undertake autonomously.

Experts in the field offer the first comprehensive review of the tectonics and magmatism of backarc basins, covering their initial rift stage to mature spreading. Complete with numerous illustrations, each of the twelve chapters focuses on a young, active backarc basin of the circum-Pacific-where volcano-tectonic processes are best studied because of their activity. Key themes in this volume include volcano-tectonics setting; cause and location; rift magmas; and hydrothermal activity. Researchers also present models of the dynamic processes occurring in backarc basins.

Solid-solution equilibria of marine evaporites are important in a wide range of science and technology. However, the data had not yet been summarized in a form that is at the same time comprehensive and permits to understand how the quinary seawater system builds up from its bounding systems. Thus the goal of the present volume is at the same time scientific and educational. The understanding of solid-solution equilibria of the various systems with respect to dissolution, precipitation and transformation of solids, their application to the evolution of brines, and a fast access to data is a necessary requirement for any modelling, especially in Geoscience. Another goal is to show the avail ability of data. Unfortunately, though solubility data are numereous there are substantial gaps, especially with respect to high temperatures. But also up to about 100 0 C data are missing for some of the systems so that they cannot be described entirely. Based on the present volume further work on the solubili ties of the minerals of marine evaporites may be promoted. The data have been viewed and collected over several years by the first author. The second author entered the preparation of the volume when it was realized that besides graphics and tables a fast access to data was required. Although both authors are responsible for the whole volume, responsibility is weighted somewhat differently for the various parts."

Seafloor investigation has long been a feature of not only seismology but also of acoustics. Indeed it was acoustics that produced depth sounders, giving us the first capability of producing both global and local maps of the seafloor. Subsequently, better instrumentation and techniques led to a clearer, more quantitative picture of the seabed itself, which stimulated new hypotheses such as seafloor spreading through the availability of more reliable data on sediment thickness over ocean basins and other bottom features. Geologists and geophysicists have used both acoustic and seismic methods to study the seabed by considering the propagation of signals arising from both natural seismic events and man-made impulsive sources. Although significant advances have been made in instrumentation, such as long towed geophysical arrays, ai r guns and ocean bot tom seismometers, the pic ture of the seafloor is still far from complete. Underwater acoustics concerns itself today with the phenomena of propagation and noise at frequencies and ranges that require an understanding of acoustic interaction at both of its boundaries, the sea surface and seafloor, over depths ranging from tens to thousands of meters. Much of the earlier higher frequency (>1 kHz) work included the characterization of the seafloor in regimes of reflection coefficients which were empirically derived from surveys. The results of these studies met with only limited success, confined as they were to those areas where survey data existed and lacking a physical understanding of the processes of reflection and scattering.

Opening Speech of the ICEDIVE 84 Conference by His Royal Highness Prince Bertil of Sweden I am very pleased to be invited to open the International Conference ICEDIVE 84, dealing with medical and technical problems of diving and related underwater activities in arctic conditions. Until recent times, the arctic was considered astrange and remote area of minor importance. However, in a world with diminishing natural resources, arctic areas have become a region of global importance because of their enormous resources and strategie position. Certain experts believe that more than 50% of oil reserves are "sleeping" in these northern areas which are cold, harsh and hostile to man. Operations in arctic areas are extremely difficult, expensive, and demand high levels of technical, scientific and physiological achievement. One should recall for example, that Alaskan oil investment onIy became economically viable after the 1973-1974 price explosion. Recent political/military troubles in the Gulf have increased interest in the development of polar resources. This conference is unique as it is the first time that medical and technical specialists interested in the problem of diving in arctic conditions have met in an international forum. Development of the arctic resources is a matter of international urgency, and it pleases me that scientists from the USA, Canada, the USSR, Australia and Europe have gathered here in Stockholm to present their experience and to discuss problems in this field.

This book grew out of lectures on geophysical fluid dynamics delivered over many years at the Moscow Institute of Physics and Technology by the author (and, with regard to some parts of the book, by his colleagues). During these lectures the students were advised to read many books, and sometimes individual articles, in order to acquaint themselves with the necessary material, since there was no single book available which provided a sufficiently complete and systematic account (except, perhaps, the volumes on Hydrophysics of the Ocean, Hydrodynamics of the Ocean, and Geodynamics in the ten-volume Oceanology series published by Nauka Press in 1978-1979; these refer, however, specifically to the ocean, and anyway they are much too massive to be convenient for study by students). As far as we know, no text corresponding to our understanding of geophysical fluid dynamics has as yet been published outside the Soviet Union. The present book is designed to fill this gap. Since it is customary to write the preface after the entire book has been completed, the author has an opportunity there to raise some points of possible criticism by the reviewers and readers. First of all, note that this work presents the theoretical fundamentals of geophysical fluid dynamics, and that observational and experimental data (which in the natural sciences are always very copious) are referred to only rarely and briefly.

There is now an awareness within the industry, particularly as oil companies direct considerable resources towards developing diverless production systems, that a fully integrated approach to equipment design and intervention is necessary to achieve an acceptable system. The requirement for an integrated approach to equipment design and intervention is applicable not only to diverless depths but to all subsea structures, equipment and intervention techniques in whatever depth. Fortunately the inherent dexterity of the diver does not impact so severely on design as other intervention techniques. However the benefits of an integrated approach are still applicable and the use of such simple "diver aids" as cutting guides and subsea markings installed prior to the installation of jackets and subsea equipment can have a significant impact on the cost of intervention. This paper examines the requirements and limitations in designing subsea equipment for Remotely Operated Vehicle (ROV) intervention. For the oil company embarking on the development of a diverless production system, be it totally diverless because of the envisaged water depth or primarily diverless with the possibility of diver back up, the intervention techniques adopted will strongly influence the final system design. The necessity to undertake an extensive development programme to produce the optimum intervention system is very costly, requires long lead times and comprehensive testing particularly where novel solutions are adopted. It is a daunting prospect for even the most progressive of oil companies.

When, in 1966, the Gennan Research Society directed the attention of oceanographers in the Federal Republic of Ger many to problems of marine pollution, I was not enthusiastic. Emphasis on this problem area meant that other important research plans had to be postponed. But the lectures at the Third International Oceanographic Congress, September 1970, in Tokyo, and at the FAO Conference on Marine Pollution and its Effects on Living Resources and Fishing, December 1970, in Rome, convinced me that research on problems of marine pollution is a social obligation, and that the oceanographer has to take a stand. I issued public warnings about the continuing use of pesticides and had to defend myself against protests by the fishing industry and many colleagues who were, in Novem ber 1970, unaware of the extent of the threat. Thus, I was required by my profession to acquire an overview of the prob lems of ocean pollution. In 1971 I only needed to familiarize myself with some one hundred bibliographical items. In the interim, the flood of data has risen dramatically, and in the year 1975, no fewer than 868 publications under the heading of "Marine Pollution" were reported (Table 1). It is, therefore, more and more diffi cult to distinguish new results of scientific research from the many repetitions and variations, and I fear that from year to year my efforts to illustrate the actual status of the problem at a given moment will be subject to more gaps."

The monograph presented to foreign readers has been prepared by the famous Soviet investigators of processes of geochemistry and sedimentation in the Mediterranean Sea. For more than 20 years E.M. Emelyanov has examined the recent sedimentation of the Mediterranean Sea and K.M. Shimkus has studied the Quaternary and the earlier sedi mentation of the area. The authors, scientific workers from the P.P. Shirshov Institute of Oceanology, USSR Academy of Sciences (Atlantic and Southern Depart ments), took part not only in numerous cruises on oceanographic vessels of the USSR, but in the study of cores of the deep-sea drilling on R/V "Glomar Challenger." A great number of scientific papers and some books devoted to the processes of sedimentation and geochemistry of the Mediterranean Sea were written by them. Although the scientific interests of the authors are not only limited to these questions, I should like to emphasise these aspects of their scientific activity when introducing this book. The Mediterranean Sea is a suitable natural laboratory for solving a number of principal problems of marine sedimentation and lithogenesis."

The impetus for the conference held at Bombannes, France in May, 1982 arose out of a Scientific Committee on Oceanic Research (SCOR) Working Group on "Mathematical Models in Biological Oceanography." This group was chaired by K.H. Mann and held two meetings in 1977 and 1979. At both meetings it was felt that, although reductionist modelling of marine ecosystems had achieved some successes, the future progress lay in the development of holistic ecosystem models. The members of the group (K.H. Mann, T. Platt, J.M. Colebrook, D.F. Smith, M.J.R. Fasham, J. Field, G. Radach, R.E. Ulanowicz and F. Wulff) produced a critical review of reductionist and holistic models which was published by the Unesco Press (Platt, Mann and Ulanowicz, 1981). One of the conclusions of this review was that, whether holistic or reductionist models are preferred, it is critically important to increase the scientific effort in the measurement of physiological rates for the computation of ecological fluxes. The Working Group therefore recommended that an international meeting should be organized which would attempt to bring together theoretical ecologists and biological oceanographers to assess the present and future capability for measuring ecological fluxes and incorporating these data into models. An approach was made to the Marine Sciences Panel of the NATO Science Committee who expressed an interest in funding such a meeting. They awarded a planning grant and a planning group was formed consisting of M.J.R. Fasham, M.V. Angel, T. Platt, R.E.

Primary productivity in the sea accounts for 30% of the total global annual production. Holistic understanding of the factors determining marine productivity requires detailed knowl edge of algal physiology and of hydrodynamics. Traditionally studies of aquatic primary productivity have heen conducted hy workers in two major schools: experimental laboratory biology, and empirical field ecology. Here an attempt was made .to hring together people from both schools to share information and con cepts; each author was charged with reviewing his field of exoer tise. The scope of the Symposium is broad, which we feel is its strength. We gratefully acknowledge financial support from the Depart ment of Energy, the United States Environmental Protection Agency, the National Oceanic and Atmospheric Administration, including the NMFS Northeast Fisheries Center and the MESA New York Bight Project. Thanks are due to Mrs. Margaret Dienes, with out whose editorial skills this volume could not have been pro duced, and to Mrs. Helen Kondratuk as Symposium Coordinator. Finally, we wish to record our indebtedness to Dr. Alexander Hollaender for his tireless efforts and valuable advice in sup porting all aspects of this Symposium."

The oceans are vast with t, Yo-thirds of our planet being covered by a thick layer of water, the depth of which can be likened to flying above the earth's surface at an altitude of 30,000 feet (9,800 m). Good to play in, essential for life but deadly to breathe, water is important to all organisms on the planet, and the oceans form its major reservoir containing approximately 97 per cent of all freely available surface water. In spite of this obvious importance mankind has still much to learn about this ocean environment. Study of the oceans has grown enormously since the eighteenth- and nineteenth-century voyages of scientific discovery, expanding greatly in the period post 1945. One of the subjects that has blossomed in this period has been the study of the ocean's surface, and in particular the study of sea level and related sea-surface changes. Indeed this topic may even be termed 'popular', as reflected in the growing number of general geo morphology, physical geology and oceanography texts which now give space to the subject."

Improvements in the design process as applied to ocean structures have received intense interest in recent years. Part of this interest stems from the growing realization that design on a purely deterministic basis is inadequate for structures sub ject to random loads, which are best described by statistical (or probability) methods. This book is an attempt to bridge the gap between present design practices and available analytical techni ques (which may be exploited to improve present procedures). The book itself is an outgrowth of a set of notes prepared for an intensive short course presented over the past three years by the Engineering Extension Division of the University of California at Los Angeles, California. The ensuing presentation is composed of four parts. The material begins with a review of the physical environment (winds, surface gravity water waves and currents) for which engineering type formulations are presented. Hindcasting and forecasting techniques using spectral concepts are included. Special problem areas are enumerated."

The three main missions of any organism--growing, reproducing, and surviving--depend on encounters with food and mates, and on avoiding encounters with predators. Through natural selection, the behavior and ecology of plankton organisms have evolved to optimize these tasks. This book offers a mechanistic approach to the study of ocean ecology by exploring biological interactions in plankton at the individual level. The book focuses on encounter mechanisms, since the pace of life in the ocean intimately relates to the rate at which encounters happen.

Thomas Kiorboe examines the life and interactions of plankton organisms with the larger aim of understanding marine pelagic food webs. He looks at plankton ecology and behavior in the context of the organisms' immediate physical and chemical habitats. He shows that the nutrient uptake, feeding rates, motility patterns, signal transmissions, and perception of plankton are all constrained by nonintuitive interactions between organism biology and small-scale physical and chemical characteristics of the three-dimensional fluid environment.

Most of the book's chapters consist of a theoretical introduction followed by examples of how the theory might be applied to real-world problems. In the final chapters, mechanistic insights of individual-level processes help to describe broader population dynamics and pelagic food web structure and function."

The Eighty-Second National Meeting of the American Institute of Chemical Engineers, held in Atlantic City, New Jersey, from August 29 through September 1, 1976, had as one of its themes the topic of transport processes. One of the sessions related to this theme was "Transport Processes in the Oceans" chaired by R. P. Shaw and R. J. Gibbs. This session was devoted to the study of transport processes and their hydrodynamic modeling in large water bodies such as oceans and lakes; transport of both dissolved and solid material was con sidered. The interest developed at the session led to the conclu sion that the papers presented there should be published as a set rather than dispersed among the various technical journals that rep resent the wide variety of technical affiliations of the authors. This variety, in fact, is typical of this particular field with con tributors identified as chemical engineers, civil engineers, environ mental engineers, mechanical engineers, oceanographers and applied mechanicians to name just a few. Such an interdisciplinary area re quires more effort in keeping abreast of developments than do the traditional areas, since new material may be developed and presented in a wide range of technical journals and professional meetings."

Deep-sea manganese nodules, once an obscure scientific curios ity, have, in the brief span of two decades, become a potential mineral resource of major importance. Nodules that cover the sea floor of the tropical North Pacific may represent a vast ore de posit of manganese, nickel, cobalt, and copper. Modern technology has apparently surmounted the incredible problem of recovering nodules in water depths of 5000 meters and the extraction of metals from the complex chemical nodule matrix is a reality. Both the recovery and the extraction appear to be economically feasible. Exploitation of this resource is, however, hindered more by the lack of an international legal structure allowing for recognition of mining sites and exploitation rights, than by any other factor. Often, when a mineral deposit becomes identified as an ex ploitable resource, scientific study burgeons. Interest in the nature and genesis of the deposit increases and much is learned from large scale exploration. The case is self evident for petrol eum and ore deposits on land. The study of manganese nodules is just now entering this phase. What was the esoteric field of a few scientists has become the subject of active exploration and research by most of the industrialized nations. Unfortunately for our general understanding of manganese nodules, exploration results remain largely proprietary. However, scientific study has greatly increased and the results are becoming widely available."

The era of the exploration of the World Ocean is not yet over: some areas still lack an adequate number of observations. The relationships between the physical, chemical and biological processes, which sustain the life on this planet, are not yet fully understood. In short, knowledge of the oceans is still far from satisfactory. This book covers an important period in the study of one of the last investigated areas of the World Ocean: the Ross Sea, Antarctica. During the 1990s, long-term experiments were conducted in this area as part of the Climatic Long-term Interaction for the Mass balance in Antarctica (CLIMA) project of the Italian National Programme for Antarctic Research (PNRA), providing a wealth of oceanographic information. This book is an outcome of the CLIMA field obser vations and international collaborations with the most important programmes in the Ross Sea-Southern Ocean area. It contributes to the st ldies of the spatial and temporal variability of Ross Sea water masses and circulation and their relation ship with the Southern Ocean circulation. A comprehensive review of historical data is offered, and new data sets are analysed. The studies presented in this book show that much progress has been achieved during the last decade, but large gaps in our understanding of the physical processes in the Ross Sea are still to be filled. However, these studies contribute significantly to the investigation of some specific aspects regarding the circula tion of the main water masses."

My work Geochemistry oj organic matter in the ocean first appeared in Russian in 1978. Since then much progress has been made in the exploration of various forms of organic matter in the ocean: dissolved, colloidal, organic matter sus pended in particles and that contained in bottom sediments and in interstitial waters. The appropriate evidence is found in hundreds of articles and several re view works, such as Andersen (1977), Biogeochimie de [a matiere organique a ['interjace eau-sedimentmarine (1980), Duursma and Dawson (1981). A great amount of new information has been obtained in the Soviet Union's scientific institutions on the composition and distribution in natural waters and bottom sediments of organic matter and its separate components playing a crucial role in the formation of the chemical and biological structure of the ocean and its productivity, in the biogeochemistry of the elements and geochemistry of organic matter in the Earth's sedimentary cover. The areas of exploration have expanded over the past four-and-a-half years to embrace many new, little-known regions, including the Arctic seas. In contrast to the three preceeding decades, the research has been focused on investigating the existing forms, the distribution and accumulation of organic matter in near continental oceanic zones between land and sea, and in river estuaries.

vi These categories seem to represent the basic breakdown by field of present-day research in this area. Though each paper has been classified into one of these categories (for conference organization purpose), many papers overlapped two or three areas. It is also interesting to note that not only are scientific results being communicated, but the latest techniques and the state-of-the-art tools of the trade (existing and in development) are also being presented. The forty-six papers presented at this conference represent the work of seventy scientists working at universities, government laboratories, and industrial laboratories in seven different countries . We would like to thank the contributors for their efforts and especially for their promptness in providing the editors with their final manuscripts. William A. Kuperman Finn B. Jensen La Spezia, Italy July 1980 CONTENTS GEOACOUSTIC PROPERTIES OF MARINE SEDIMENTS Attenuation of Sound in Marine Sediments . * 1 J. M. Hovem Directivity and Radiation Impedance of a Transducer 15 Embedded in a Lossy Medium . ** ****** G. H. Ziehm Elastic Properties Related to Depth of Burial, Strontium Content and Age, and Diagenetic Stage in Pelagic Carbonate Sediments . . * * . * * * . 41 M. H. Manghnani, S. O. Schianger, and P. D. Milholland Application of Geophysical Methods 'and Equipment to Explore the Sea Bottom . ** ***. * 53 H. F. Weichart The Acoustic Response of Some Gas-Charged Sediments in the Northern Adriatic Sea * * * * . * * * * 73 A.