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Carr spent more than thirty years dedicated to the study of the ecology and migration of sea turtles. Many of the stories he had heard from the turtle captains had been confirmed through tag returns from all over the Caribbean. The riddle of the ridley had been solved and documented by an old, grainy film, but it virtually disappeared during the 1960s. Carr's research extended beyond Tortuguero and the Caribbean to include Ascension Island, and he collaborated with other scientists to produce ambitious theories regarding olfaction, vision, and the role of seafloor spreading. Carr and his students participated in the Western Atlantic Turtle Symposium, an event that suggested growing interest in the ecology and conservation of sea turtles. Nevertheless, questions still remained. Sargassum mats had initially seemed promising as a refuge for sea turtles during their lost year, but oceanic zones of convergence (including sargassum) seemed to be a more promising explanation.

This chapter discusses paleomagnetic research that focused on spreading seafloors and their relevance to continental drift. By 1964, paleomagnetic research was already shifting direction. No longer would the emphasis be on determining past pole positions; now the research swung to using the magnetic reversals to date rocks. To everyone's surprise, including the scientists involved, it would turn out to be the reversals that would ultimately corroborate continental drift. But first the paleomagnetists had to convince themselves that the reversals reflected actual changes in the Earth's magnetic field rather than being attributable to self-reversal or some other unknown process. The way to find out was to determine whether rocks of the same age from different locations all had the same magnetic polarity: normal or reversed. Basalts are the most strongly magnetized rocks, and by the early 1960s, geologists had learned how to measure their ages using the decay of potassium to argon. This chapter also considers Harry Hess's theory of seafloor spreading as well as the work of Robert Sinclair Dietz.

This chapter discusses the influence of Harry Hess's theory of seafloor spreading on other scientists who were studying continental drift. Fred Vine, inspired by Hess's talk at Cambridge in January 1962, titled his student address to the Cambridge Geology Club “HypotHESSes.” In the early 1960s, it was a rare geologist who knew and accepted both that the Earth's magnetic field had reversed and that the seafloors were spreading from the ridges. Vine set to work interpreting Drummond Matthews' magnetic data from the Carlsberg Ridge, focusing on two puzzling underwater volcanic seamounts. He then wrote up a short paper and submitted it to Nature, which published “Magnetic Anomalies Over Ocean Ridges” on September 7, 1963. Vine also collaborated with the Canadian geologist Tuzo Wilson to study the magnetic patterns on either side of the Juan de Fuca Ridge off Vancouver Island in the Pacific Northwest. This chapter also considers the work of Allan Cox, Brent Dalrymple, and Richard Doell dating and measuring the magnetic polarity of volcanic rocks of different ages.

This chapter explains the concepts of continental drift, seafloor spreading, plate tectonics, and mantle convection to address the origin of the most striking features of the Earth’s surface. These include land areas and ocean regions, mountain ranges such as volcanic and nonvolcanic mountains, deep trenches, and sunken islands in the Pacific region.

This chapter discusses those fishes characteristically found on or over complex seafloor habitats comprising various amounts of cobble, boulders, and rock outcrops in water depths ranging from 30 to 500 m. This depth range encompasses the continental shelf and upper continental slope of California. This chapter also discusses those fishes associated with such artificial structures as oil platforms off Southern California at similar depths. Because very little is known of fish assemblages associated with deep rock habitats off Baja California, this chapter limits the discussion to California waters.

Below the euphotic epipelagic zone is the realm of deep-sea fishes. The depth zones of this major portion of the earth's oceans have been characterized by the physical features and types of organisms present. Many deep-sea fishes are bioluminescent, even though light production would seem to make them stand out in their dark world. The photophores of many mesopelagic and bathypelagic fishes are, however, arranged in rows along the ventral surface of the animal. These are thought to provide counterillumination by producing light that is similar to the ambient light in color, intensity, and angular dispersion. Near the seafloor of even the world's deepest oceans, one finds that the fishes are typically much larger, more substantial, and usually more active than those of the overlying midwaters. This chapter also presents general differences in the characteristics of fishes from the epipelagic through the benthopelagic regions of the open ocean.

This chapter discusses the major features of the ocean and its natural history. It begins with a brief discussion on the topography of the sea surface and explains how ocean basins are produced by seafloor spreading. The chapter then discusses patterns of sea-surface currents, wind strengths, generation of waves, and how basins exchange water. It also considers nutrient fertilization, ocean productivity, and the diversity of life in the sea.

This chapter discusses some of the surprising ideas on continental drift that emerged after World War II. In 1965, a young Princeton postdoctoral student named W. Jason Morgan had been poring over photographs of the Moon, seeing what he could deduce from the heights of the walls and central peaks of lunar craters. Before long he had switched his interest from the faraway Moon to the inaccessible deep-sea trenches. Morgan began to explore Arthur Holmes's idea that a pair of descending convection cells might drag down the crust and create the great deeps. This chapter also takes a look at the map created by Bruce Heezen, Marie Tharp, and Maurice Ewing depicting the the seafloor of the Atlantic Ocean, along with research that provided rigorous quantitative evidence relevant to continental drift.

This chapter focuses on what turns out to be the discovery of the twentieth century: the key insight that turned seafloor spreading and continental drift into plate tectonics. In his 1965 article on transform faults, Tuzo Wilson wrote: “Movements of the Earth's crust are concentrated in mobile belts, which may take the form of mountains, mid-ocean ridges or major faults with large horizontal movements. The plates between the mobile belts are not readily deformed except at their edges.” Just as Wilson had noticed that earthquakes along the Mid-Atlantic Ridge's fracture zones “end abruptly” and do not extend beyond the ridge crest, Jason Morgan published a 1968 paper, “Rises, Trenches, Great Faults, and Crustal Blocks,” that captures the essence of plate tectonics. This chapter also considers the work of other scientists such as Lamonter Xavier Le Pichon, Tanya Atwater, John Dewey, and F. M. Bird to explain the correlation between plate tectonics and the large-scale features of continental geology.

This chapter examines how observational studies can help in the design, execution, and interpretation of biodiversity-ecosystem function relationships. It first analyses the heterogeneous nature of seafloor landscapes and how interactions between processes occurring on different temporal and spatial scales give rise to complex and interesting dynamics that characterise many benthic marine ecosystems. It then explores the role of observations in studying ecosystem functioning, assesses the relevance of scaling laws to BEF, and considers a more integrative approach to empirical research in BEF studies.

This chapter describes a mathematical model of tsunami propagation (transient waves). A tsunami is a series of ocean waves triggered by large-scale disturbances of the ocean, including earthquakes, as well as landslides, volcanic eruptions, and meteorites. Tsunamis have very long wavelengths (typically hundreds of kilometers). They have also been called “tidal waves” or “seismic sea waves,” but both terms are misleading. The chapter first considers the boundary-value problem before modeling two special cases of tsunami generation, one due to an initial displacement on the free surface and the other due to tilting of the seafloor. It also discusses surface waves on deep water and how fast the wave energy propagates and concludes with an analysis of leading waves due to a transient disturbance.

The 1990s witnessed a significant increase in popular interest in the US regarding the geography of the world’s coastal and marine spaces. Factors motivating this renewed interest included growing public environmental awareness, a decade of unusually severe coastal storms, more frequent reporting of marine pollution hazards, greater knowledge about (and technology for) depleting fishstocks, domestic legislation on coastal zone management and offshore fisheries policies, new opportunities for marine mineral extraction, heightened understanding of the role of marine life in maintaining the global ecosystem, new techniques for undertaking marine exploration, the 1994 activation of the United Nations Convention on the Law of the Sea, reauthorization of the US Coastal Zone Management Act in 1996, and designation of 1998 as the International Year of the Ocean. Responding to this situation, the breadth of perspectives from which coastal and marine issues are being encountered by geographers, the range of subjects investigated, and the number of geographers engaging in coastal-marine research have all increased during the 1990s. As West (1989a) reported in the original Geography in America, North American coastal-marine geography during the 1980s was focused toward fields such as coastal geomorphology, ports and shipping, coastal zone management, and tourism and recreation. Research in these areas has continued, but in the 1990s, with increased awareness of the importance of coastal and marine areas to physical and human systems, geographers from a range of subdisciplines beyond those usually associated with coastal-marine geography have begun turning to coastal and marine areas as fruitful sites for conducting their research. Climatologists are investigating the sea in order to understand processes such as El Niño, remote-sensing experts are studying how sonic imagery can be used for understanding species distribution in three-dimensional environments, political ecologists are investigating the ocean as a common property resource in which multiple users’ agendas portend conflict and cooperation, and cultural geographers are examining how the ocean is constructed as a distinct space with its own social meanings and “seascapes.” Despite (or perhaps because of ) this expansion in coastal-marine geography, the subdiscipline remains fragmented into what we here call “Coastal Physical Geography,” “Marine Physical Geography,” and “Coastal-Marine Human Geography.”

Mining the extensive accumulations of minerals on the seafloor of the deep ocean might provide important resources, but it also has the potential to lead to widespread environmental impacts. Some of these impacts are unknown, and some may differ for the three main resource types: polymetallic nodules, seafloor massive sulphides, and polymetallic (cobalt-rich) crusts. Here, we detail the mining processes and describe the ecosystems associated with the minerals of interest. We then explain the expected impacts of mining, and discuss their potential effects on deep-ocean ecosystems. We also highlight the missing evidence needed to underpin effective environmental management and regulation of the nascent deep-sea mining industry.

In 1912 a German Meteorologist, Alfred Wegener, took the drastic step of moving into another science altogether by publishing the shocking geologic theory that our continents have been sailing across the surface of the earth like leaves on a lake blown by—what? The geologists laughed at the suggestion of an impossible wind and scorned the man who had insolently crossed the boundaries of the sciences. But truth be told, it wasn’t unheard of in those early years to do just that. Rutherford, a physicist, had won the Nobel Prize in chemistry, and Marie Curie had already won twice, once in physics and once in chemistry. Wegener himself had done his PhD work in astronomy before switching over to meteorology, and at the same time was a renowned arctic explorer. The separation between the sciences are useful and real—a biology student has enough to learn without spending years on tensor analysis or relativity— but at their boundaries they blur. Today nearly everyone pays lip service to what we call interdisciplinary research, but in practice they fight hard against it. I did my PhD course work in the chemistry department of the University of Florida and my research in the physics group at Oak Ridge, then had a postdoc appointment in the chemistry department at Brookhaven before going to physics at Cornell and ending up in geology at Miami, but I had to fight along the way. A chemistry professor at Florida tried to insist that I take his colloid course instead of relativity (which was taught at the same time). I won that fight but lost at Cornell when I tried to have my students take chemistry courses instead of the required engineering and physics courses. The fact that Wegener wasn’t a geologist gave them an easy way out: it’s easier to laugh at new ideas than to confront them, and easier still to laugh at new ideas from those whom you can consider amateurs.

The previous chapter showed how the reverse Euler method can be used to solve numerically an ordinary first-order linear differential equation. Most problems in geochemical dynamics involve systems of coupled equations describing related properties of the environment in a number of different reservoirs. In this chapter I shall show how such coupled systems may be treated. I consider first a steady-state situation that yields a system of coupled linear algebraic equations. Such a system can readily be solved by a method called Gaussian elimination and back substitution. I shall present a subroutine, GAUSS, that implements this method. The more interesting problems tend to be neither steady state nor linear, and the reverse Euler method can be applied to coupled systems of ordinary differential equations. As it happens, the application requires solving a system of linear algebraic equations, and so subroutine GAUSS can be put to work at once to solve a linear system that evolves in time. The solution of nonlinear systems will be taken up in the next chapter. Most simulations of environmental change involve several interacting reservoirs. In this chapter I shall explain how to apply the numerical scheme described in the previous chapter to a system of coupled equations. Figure 3-1, adapted from Broecker and Peng (1982, p. 382), is an example of a coupled system. The figure presents a simple description of the general circulation of the ocean, showing the exchange of water in Sverdrups (1 Sverdrup = 106 m3/sec) among five oceanic reservoirs and also the addition of river water to the surface reservoirs and the removal of an equal volume of water by evaporation. The problem is to calculate the steady-state concentration of dissolved phosphate in the five oceanic reservoirs, assuming that 95 percent of all the phosphate carried into each surface reservoir is consumed by plankton and carried downward in particulate form into the underlying deep reservoir. The remaining 5 percent of the incoming phosphate is carried out of the surface reservoir still in solution.