Ch. 4— Technologies for Exploring the Exclusive Economic Zone * 151 



Hard mineral exploration, however, is a task 

 well-suited for manned vehicles and tethered, free- 

 swimming ROVs. A wide array of manipulator- 

 held sampling equipment for these vehicles has been 

 developed over the past two decades. This sampling 

 capability ranges from simple scoops to gather un- 

 consolidated sediment to drills for taking hard-rock 

 cores. Present undersea vehicles cannot, however, 

 collect soft sediment cores much beyond 3 feet in 

 length or hard-rock cores more than a few inches 

 in length. 



The Continuous Seafloor Sediment Sampler is 

 an example of a specially designed vehicle. Vehi- 

 cles of this type might find extensive application 

 in the EEZ by providing relatively rapid mineral 

 assays of the bottom within areas of high interest. 

 If supported with appropriate navigation equip- 

 ment, a surficial mineral constituent chart could 

 be developed fairly rapidly. Due to the vehicle's 

 present design, such a map could only be made over 

 bottoms composed of unconsolidated, fine-grained 

 sediments. 



A recent example of a vehicle application was the 

 search for and subsequent examination of the RMS 

 Titanic, which sank in the Atlantic in 1912. The 

 vessel was thought to be somewhere within a 120- 

 square-nautical-mile area. A visual search with an 

 undersea vehicle could literally take years to com- 

 plete at the 4,000-meter (13,000-foot) depths in 

 which she lay. Instead, the area was searched using 

 a side-looking sonar which detected a target of likely 

 proportions after about 40 days of looking. To ver- 

 ify that the target was the Titanic, the towed vehi- 

 cle ANGUS was dispatched with its television and 

 still cameras. The next step, to closely examine the 

 vessel, was done with the manned vehicle Alvin and 

 the tethered, free-swimming ROV Jason Junior 

 (JJ). Alvin provided the means to "home on" and 

 board the vessel, while JJ provided the means to 

 explore the close confines of the vessel's interior. 



The search for the space shuttle Challenger de- 

 bris is another example of the division of labor be- 

 tween undersea vehicles and over-the-side tech- 

 niques. Since the debris was scattered over many 

 square miles and intermixed with debris from other 

 sources, it would have taken months, perhaps years, 

 to search the area with undersea vehicles. Instead, 

 as with the Titanic, side-looking sonar was used 



to sweep the area of interest and likely targets were 

 plotted to be later identified by manned and un- 

 manned vehicles. The same vehicles were subse- 

 quendy used to help in the retrieval of debris. Once 

 again, the large area was searched with the more 

 rapid over-the-side techniques while precision work 

 was accomplished with the slower moving under- 

 sea vehicles. 



These two examples suggest that the main role 

 of undersea vehicles in the EEZ is and will be to 

 provide the fine details of the bottom. A typical ex- 

 ploration scenario might begin with bottom cov- 

 erage with a wide-swath side-looking sonar, like 

 GLORIA, progress to one of the midrange side- 

 looking sonars or a Sea Beam-type system, and end 

 with deployment of a towed vehicle system or a 

 tethered, free-swimming ROV or manned sub- 

 mersible to collect detailed information. 



Needed Technical Developments 



Thanks to technological advances in offshore oil 

 exploration, the tools, vehicles, and support systems 

 available to the EEZ minerals explorer have increased 

 dramatically in numbers and types since the 1960s. 

 It would appear that adequate technology now ex- 

 ists to explore selected areas within the EEZ using 

 undersea vehicles. But, as with offshore oil, some 

 of these assets wiU probably prove to be inadequate 

 when they are used for hard mineral exploration 

 instead of the tasks for which they were designed. 

 Identification of these shortcomings is probably best 

 accomplished by on-the-job evaluation. 



More than likely, whatever technological im- 

 provements are made will not be so much to the 

 vehicles themselves but to the tools and instrumen- 

 tation aboard the vehicles that collect the data. 

 Hence, it is important to identify precisely the data- 

 collecting requirements for hard mineral explora- 

 tion and mining. Potential discovery of new under- 

 water features, processes, and conditions must also 

 be anticipated. For example, prior to 1981, noth- 

 ing was known of the existence of deepwater vents 

 or of the existence of the animals that inhabit these 

 areas. Once the vents and their associated fauna 

 were discovered, tools and techniques for their in- 

 vestigation were developed as necessary. 



Certain aspects of undersea vehicles and' their 

 equipment are perennial candidates for improve- 



