529 THE DEEP SEA RESOURCES John D. Lewis INTRODUCTION mination of the control of these re­ sources. This paper examines the deep The seabeds and ocean floors have seabeds and ocean floors beyond the recently been thrust into the interna­ Continental Shelf and inquires into the tional arena by a Maltese proposal that state of oceanology, with regard to the the United Nations assume jurisdiction exploration and exploitation of these over this new frontier. l The proposal resources. It aims thus to provide a basis made in 1967 by the Maltese Represen­ for evaluating between political, mili­ tative included a second requirement: tary, and economic factors, including an that the resources to be found on the examination of the legal arrangements seabed and subsoil should be reserved I.!-ppIicable to the regulation of these for all mankind. Suddenly, nations, even those com­ interactions as well as of those com­ pletely landlocked, could see the pos­ bined effects upon future military and sible benefits of such a proposal. The political planning for the United States. mere statement of this proposal also revived some longstanding questions I--THE SEA ENVIRONMENT about "freedom of the seas" and rnili­ Man has only charted 5 percent of tary use of oceanic arcas. As well, it thc ocean floorl--even though there is highlighted somc ncwer problems, Stich no known point more than 7 rniles as the economic exploitation of the below the surface of the sea--while in seabed and ocean subsoils and the deter- outer space he has successfully mapped 530 and charted the hidden side of the with much greaLrr topographic ex­ moon. True, this land is covered by tons tremes. Although there are large areas of water and often described as a hostile that are flat, modern echo-sounding no-man's-land. Several years ago Rear Lechniques and underwaLcr photography Adm. John S. Thach, speaking of the reveal deep troughs, major submarine hydrospace environment of this planet, moun Lain chains, and tall, isolated described it realistically: mountains with both steep and gentle ... right off our doorsteps is a rela­ slopes. According to one geologist, tively unexplored jungle; whole moul1- ahout 80 percent of the oceans consist tain ranges, deep canyons, and many of hroad elevations and depressions at strange creatures are hidden there depths of 3,000 to 6,000 meters.4 The beneath millions of eubie miles of sea areas formerly described as "plains" are water. This liquid space, about which we know so little, is a murky mass of getting gradually smaller on charls of discontinuities, full of sound ducts, the ocean, as more and more detail current, and thermal layers. Most in­ becomes known.s The ocean basins are credible of all is the noise racketing 2 separated by long mountain ranges such through the undersea jungle. as the Mid-Atlantic Ridge which runs Of this three-dimensional ocean space, the entire length of the Atlantic Ocean. only the surface and a small portion of In places the mountaintops rise to form the top layer have been used until islands, while in othet locations sea­ recently_ Today, the seabed and subsoil mounts are the predominant feature. of the deep ocean floor are being The Pacific Ocean contains thousands of assaulted as the last frontier on this seamounts which rise from the seabed planet. With respect to the distribution several kilometers. In some locations of this ocean space, the Continental sediment lavers cover the ocean floor to Shelf Convention defined the limit of depths of 700 to 1,000 meters. The the Continental Shelf as being out to sediment consists of silt and remains of the 200-meter depth line. The limit, sea creatures that have drifted to the however, was made an elastic one, for bottom of the sea over the past millions the Convention added: or, beyond that of years. Close to the shore these limit, to where the depth of the super­ sediments, or mud deposits, accumu­ jacent waters admits of the exploitation lated from large drainage river systems. 3 of resources. The boundary between In deeper water the dominant sedimcnts the Continental Shelf and the deep consist of oozes and clays with various ocean is a transitional area called the chemical compositions.6 This cover continental slope. From the shoreline could mask many irregularities to pro­ out to where the continental slope duce the often described flat surface of begins, the ocean is shallow; but once the seabed. In other areas of the ocean, the continental slope is reached, the sea for instance between Tahiti and Mexico, floor plunges downward to 2,000 the sediment is nonexistent.' The thick­ meters, 3,300 or even 7,000 meters. The ness of the earth's crust on the ocean continental slope is really the boundary floor is only about 3Y2 miles as com­ or wall enclosing the deep ocean. Many pared with 12 to 32 milcs on land. This geologists describe -the Continental Shelf difference has enticed scientists to look as part of the land with the continental to the sea as a quicker way to reach the slope as the shores of the deep ocean. It earth's mantle. is the deep ocean, covering 65 percent A knowledge of the deep ocean of the earth's surface, that is the pri­ environment is essential to the under­ mary concern in this papcr. sLanding of the problems concerning the The relief features of the ocean economic, political, or military signifi­ floors are similar to those found on land cance of this area of the globe. It is 531 wholly unlike any other part of the submersibles, cilher constructed or globe and is marked by one special under construction. Several countries feature: its dynamic nature. have built and used submersibles in· c1uding Great Brilain, France, Hussia. II··EXPLORATION OF THE DEEP SEA Switzerland, Canada, and the United The methods used to explore the States. Of this number, 20 arc con· deep ocean floors and subsoil are as structed to operate below 330 meters diverse as its terrain. In a sense it is a and four down to 3,800 meters, the revolution of ocean technology: first, in mean depth of the sea, below which 44 adapting man and machinery to the percent of the seabed lies.4 These fairly easy tasks of the Continental submersibles are versatile platforms con· Shelf; and second, extending this ability taining positioning equipment, search· into the abysses of the deep seas. lights, remote control mechanical arms, Since World War II there has been an television monitoring cameras, sonar, awakening of active interest in the and even computers. Speed is sacrificed exploration of the sea. Before then the for endurance and three·dimensional primitive techniques of studying the manoeuverability. At present, sustained deep ocean floor consisted of sounding operations are limited to depths above by lead and line and bollom floor 200 meters, but by the year 2000 sampling. This method was used to increased sophistication in ocean tech· survey the ocean floor for the first nology could make the ocean floors at Atlantic cable laying in 1866.1 In 1960 6,000 meters accessible to industrial s ocean exploration was still reaching for operations. The second group, explora. the bottom, though the methods were tion by remote unmanned methods, more sophisticated; Professor Piccard's includes robots, television and camera, deep probing bathysphere, for instance, sonar survey, coring, gravity and mag· reached the ocean's deepest point.2 The netic variation surveys. Until manned feasibility of man descending deeper submersibles reach the depth desired for into the sea was realized in 1957 by sustained deep ocean survey work, these applying the simple lessons learned from remote systems will continue to be aircraft construction practices. The key relied upon. Many systems are used in was to utilize structural materials with both applications, such as television higher ratios of strength to density and monitoring of both the interior of the to design submersibles to such high submersible and the ocean floor itself. precision that a low factor of safety was Sonar is an indispensable tool for navi· tolerable.3 gation and survey aboard the submer­ No single item did more to further sibles. Sonar not only serves to define the exploration of the deep sea than the the irregular surfaces of the ocean floor echo sounder; invented in 1911 by the but also to identify stratification be­ American physicist Reginald Fessenden, tween the surface and the basement its usc has resulted in extensive charting rock. Determination of the sediment of the ocean floor. layers and the structure of the deep The methods for exploring the deep ocean rock beds is possible from these oceans and subsoils fall in two distinct surveys. Thus seismic sections can be groups: manned vehicles and unmanned, constructed identifying the crustal remotely directed vehicles and instru· material as well as their thicknesses.6 ments. In thc first group, the military The seismic survey of the suhsoil uses submarine has bCI'n joined by dozens of the refraction method rather than the submersibles employing techniques ordinary echo-sounder method used to learned from their l11ilitary forerunners. measure the depth of the sea. In the By 1967 there were some 29 research refraction method, the time that sound 532 Fig. 1-Depth Capabilities of Deep Diving Research Subrnersiblosa Seabed areas, as a percentage of the earth's surface are shown on the bar graph at the left edge. Curve represents percentage of earth's surface, on abscissa, above the depth indicated on the ordinate. o 2,000 DEEP QUEST PISCES DSRV C/) ffi 4,000 I-w ::E ALUMINAUT z 6,000 TRIESTE II J: l­e.