The Sea Floor


Book Description

Man's understanding of how this planet is put together and how it evolved has changed radically during the last 30 years. This great revolution in geology - now usually subsumed under the concept of Plate Tectonics - brought the realization that convection within the Earth is responsible for the origin of today's ocean basins and conti nents, and that the grand features of the Earth's surface are the product of ongoing large-scale horizontal motions. Some of these notions were put forward earlier in this century (by A. Wegener, in 1912, and by A. Holmes, in 1929), but most of the new ideas were an outgrowth of the study of the ocean floor after World War II. In its impact on the earth sciences, the plate tectonics revolution is comparable to the upheaval wrought by the ideas of Charles Darwin (1809-1882), which started the intense discussion on the evolution of the biospere that has recently heated up again. Darwin drew his inspiration from observations on island life made during the voyage of the Beagle (1831-1836), and his work gave strong impetus to the first global oceanographic expedition, the voyage of HMS Challenger (1872- 1876). Ever since, oceanographic research has been intimately associ ated with fundamental advances in the knowledge of Earth. This should come as no surprise. After all, our planet's surface is mostly ocean.




Physics of Sound in Marine Sediments


Book Description

The phenomenon of sound transmissions through marine sediments is of extreme interest to both the United States civilian and Navy research communities. Both communities have conducted research within the field of this phenomenon approaching it from different perspectives. The academic research community has approached it as a technique for studying sedimentary and crustal structures of the ocean basins. The Navy research community has approached it as an additional variable in the predictability of sound trans mission through oceanic waters. In order to join these diverse talents, with the principal aim of bringing into sharp focus the state-of-the-science in the problems relating to the behavior of sound in marine sediments, the Office of Naval Research organized and sponsored an invited symposium on this subject. The papers published in this volume are the results of this symposium and mark the frontiers in the state-of-the-art. The symposia series were based on five research areas identified by ONR as being particularly suitable for critical review and for the appraisal of future research trends. These areas include: 1. Physics of Sound in Marine Sediments, 2. Physical and Engineering Properties of Deep-Sea Sediments, 3. The Role of Bottom Currents in Sea Floor Geological Processes, 4. Nephelometry and the Optical Properties of the Ocean I'laters, S. Natural Gases in Marine Sediments and Their Mode of Distribution. These five areas also form some of the research priorities of the ONR program in Marine Geology and Geophysics.




Coastal Sedimentary Environments


Book Description

Richard A. Davis The zone where land and sea meet is composed of a variety of complex environ ments. The coastal areas of the world contain a large percentage of its population and are therefore of extreme economic importance. Industrial, residential, and recreational developments, as well as large urban complexes, occupy much of the coastal margin of most highly developed countries. Undoubtedly future expan sion in many undeveloped maritime countries will also be concentrated on coastal areas. Accompanying our occupation of coasts in this age of technology is a dependence on coastal environments for transportation, food, water, defense, and recreation. In order to utilize the coastal zone to its capacity, and yet not plunder its resources, we must have extensive knowledge of the complex environ ments contained along the coasts. The many environments within the coastal zone include bays, estuaries, deltas, marshes, dunes, and beaches. A tremendously broad range of conditions is represented by these environments. Salinity may range from essentially fresh water in estuaries, such as along the east coast of the United States, to extreme hypersaline lagoons, such as Laguna Madre in Texas. Coastal environments may be in excess of a hundred meters deep (fjords) or may extend several meters above sea level in the form of dunes. Some coastal environments are well protected and are not subjected to high physical energy except for occasional storms, whereas beaches and tidal inlets are continuously modified by waves and currents.




The Sea Floor


Book Description

Man's understanding of how this planet is put together and how it evolved has radically changed during the last twenty years. This great revolution in geology now usually subsumed under the concept of Plate Tectonics and its ramifications - was an outgrowth of the study of the ocean floor. In its impact on the earth sciences, it is comparable to the revolution brought about by Charles Darwin (1809-1882) a century ago. The evolution of the biosphere was the focal point at that time. We are now discussing the evolution of the lithosphere, the uppermost 100 km of the Earth. Darwin drew his inspiration from observations made during the voyage of the Beagle, and his work gave strong impetus to the first global oceanographic expedition, the voyage of HMS Challenger (1872-1875). Ever since, oceanographic research has been intimately associated with fundamental advances in the knowledge of Earth. This should come as no surprise. After all, our planet's surface is mostly ocean. This booklet is the result of our conviction that to study introductory geology and oceanography and environment al science, one needs a summary of the tectonics and morphology of the sea floor, of the geologic processes active in the deep sea and in shelf seas, and of the climatic re cord in deep sea sedi ments. Our aim is to give abrief survey of these topics.







Arctic Ocean Sediments: Processes, Proxies, and Paleoenvironment


Book Description

Although it is generally accepted that the Arctic Ocean is a very sensitive and important region for changes in the global climate, this region is the last major physiographic province of the earth whose short-and long-term geological history is much less known in comparison to other ocean regions. This lack of knowledge is mainly caused by the major technological/logistic problems in reaching this harsh, ice-covered region with normal research vessels and in retrieving long and undisturbed sediment cores. During the the last about 20 years, however, several international and multidisciplinary ship expeditions, including the first scientific drilling on Lomonosov Ridge in 2004, a break-through in Arctic research, were carried out into the central Artic and its surrounding shelf seas. Results from these expeditions have greatly advanced our knowledge on Arctic Ocean paleoenvironments. Published syntheses about the knowledge on Arctic Ocean geology, on the other hand, are based on data available prior to 1990. A comprehensive compilation of data on Arctic Ocean paleoenvironment and its short-and long-term variability based on the huge amount of new data including the ACEX drilling data, has not been available yet. With this book, presenting (1) detailed information on glacio-marine sedimentary processes and geological proxies used for paleoenvironmental reconstructions, and (2) detailed geological data on modern environments, Quaternary variability on different time scales as well as the long-term climate history during Mesozoic-Tertiary times, this gap in knowledge will be filled. *Aimed at specialists and graduates *Presents background research, recent developments, and future trends *Written by a leading scholar and industry expert




Submarine Geomorphology


Book Description

This book on the current state of knowledge of submarine geomorphology aims to achieve the goals of the Submarine Geomorphology working group, set up in 2013, by establishing submarine geomorphology as a field of research, disseminating its concepts and techniques among earth scientists and professionals, and encouraging students to develop their skills and knowledge in this field. Editors have invited 30 experts from around the world to contribute chapters to this book, which is divided into 4 sections – (i) Introduction & history, (ii) Data & methods, (ii) Submarine landforms & processes and (iv) Conclusions & future directions. Each chapter provides a review of a topic, establishes the state-of-the-art, identifies the key research questions that need to be addressed, and delineates a strategy on how to achieve this. Submarine geomorphology is a priority for many research institutions, government authorities and industries globally. The book is useful for undergraduate and graduate students, and professionals with limited training in this field.




Sediments, Morphology and Sedimentary Processes on Continental Shelves


Book Description

The application of multibeam and sediment transport measurement technologies and the adoption of multi-faceted research methodologies have greatly advanced our understanding of the sedimentary processes on continental shelves in the last decade. This book uniquely blends cutting-edge research and state-of-the art review articles that take stock of new advances in multibeam mapping and sediment transport technologies, spatial analysis and modelling, and the applications of these advances to the understanding of shelf sediments, morphodynamics, and sedimentary processes. Case studies are also presented to illustrate the utilization of seabed property and process knowledge in habitat mapping and ocean management With its mix of papers focusing on technological advances, integration of shelf morphology and processes, and the application of these advances to coastal and ocean management, this Special Publication volume will serve as a milestone reference for professional marine scientists and as advanced text for students in marine geology, sedimentology and oceanography. This book is part of the International Association of Sedimentologists (IAS) Special Publications. The Special Publications from the IAS are a set of thematic volumes edited by specialists on subjects of central interest to sedimentologists. Papers are reviewed and printed to the same high standards as those published in the journal Sedimentology and several of these volumes have become standard works of reference.




Fine Sediment Dynamics in the Marine Environment


Book Description

Cohesive sediment, or mud, is encountered in most water bodies throughout the world. Often mud is a valuable resource, synonymous with fertile land, enriching the natural environment and used as an important building material. Yet mud also hinders navigation and consequently, dredging operations have been carried out since ancient times to safeguard navigation. Unfortunately, many mud deposits are now contaminated, endangering the eco-system and increasing the costs of dredging operations. The transport and fate of mud in the environment are still poorly understood and the need for basic research remains. This text contains the proceedings of the INTERCOH-2000 conference on progress in cohesive sediment research. It was the sixth in a series of conferences initially started by Professor Ashish Mehta in 1984 as a "Workshop on Cohesive Sediment Dynamics with Special Reference to the Processes in Estuaries". During these conferences the character of the first workshop has always been maintained, that is, small scale and dedicated to the physical and engineering aspects of cohesive sediments, without parallel sessions, but with ample time for discussions during and after the presentations, and followed by a book of proceedings containing thoroughly reviewed papers. INTERCOH-2000 was integrated with the final workshop of the COSINUS project. This project was carried out as a part of the European MAST-3 programme, and almost all European cohesive sediment workers were involved. INTERCOH-2000 focused on the behaviour and modelling of concentrated benthic suspensions, i.e. high-concentrated near-bed suspensions of cohesive sediment. Special attention was paid to: sediment - turbulence interaction; flocculation and settling velocity; high-concentrated mud suspensions; processes in the bed - consolidation; processes on the bed - erosion; field observations on mud dynamics; instrumentation; and numerical modelling.