| dc.description.abstract | 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 continents, 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 biosphere 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 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 book is the result of our conviction that to study introductory geology and oceanography
and environmental sciences, 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
record in deep-sea sediments.
Our aim is to give a brief survey of these topics. We have endeavored to write for all who
might be interested in the subject, including those with but little background in the natural
sciences. The decade of the 1980s was characterized by an increasing awareness of man’s
dependency on natural resources, including the ocean as a weather machine, a waste bin, and a
source of energy and minerals. This trend, we believe, will persist as resources become ever more
scarce and as the impact of human activities on natural cycles escalates in the coming decades.
An important part of this awareness will be an appreciation for the elementary facts and concepts
of marine geology, especially as they apply to processes within hydrosphere and atmosphere.
In what follows, we shall first give a brief overview of the effects of endogenic forces on
the morphology of the sea floor. Several excellent summaries for the general reader are
available for this topic, which is closely linked to the theory of continental drift, and has been
a focus of geologic discussion for the last three decades. For the rest, we shall emphasize the
exogenic processes, which determine the physical, chemical, and biological environment on
the sea floor, and which are especially relevant to the intelligent use of the ocean and to an
understanding of its role in the evolution of climate and life.
The results and ideas we report on are the product of the arduous labors of many dedicated
marine geologists. We introduce some particularly distinguished scientists by portrait (Fig. 0.1).
Of course, there are many more, and most of them are alive today. We have occasionally mentioned
the authors of important contributions. However, we did not find it possible in a book
like this to give credit systematically where it is due. We sincerely apologize to our colleagues
for this unscholarly attitude, citing necessity in defense. For those who wish to pursue the
subjects discussed in greater depth, we append suggested readings at the end of each chapter,
as well as a list of key references. | en_US |
