2012 David Packard Distinguished Lecturer
Dana Yoerger, Ph.D.
Senior Scientist, Deep Submergence Laboratory
Dept of Applied Ocean Physics and Engineering
Woods Hole Oceanographic Institution
Technology for scientific deep-sea exploration:
Where have we been, where are we now, and where are we going?
Wednesday — November 28, 2012
Pacific Forum — 3:00 p.m.
Since Heezen and Tharp published the first comprehensive map of the entire ocean floor in 1977, our understanding of the deep seafloor has progressed rapidly. As in any scientific endeavor, enabling technologies have played critical roles. At the time, the prospect of publishing peer-reviewed work based on observations from submersibles was greeted in many circles with skepticism. Further innovations, including tow sleds, remotely operated vehicles, and autonomous platforms were likewise initially dismissed by the mainstream oceanographic community as impractical, too expensive, or ill-suited to examining important scientific questions. Today, the partnership between advanced technology and scientific discovery is unquestioned.
In this talk, I will review some of that history, especially aspects I have observed and participated in since I entered the field in 1979. These include the introduction of dynamic positioning on our research vessels and the introduction of remotely operated vehicles (ROVs) in the 1980s. In that period, we improved our understanding of underwater vehicle dynamics and introduced accurate localization, automatic control, and precise mapping into the ROVs. These lessons would later prove critical to our early autonomous vehicles (AUVs). Our autonomous vehicle work with the AUV ABE initially focused on repeated long term observations of vent sites, but was realigned to Mid-Ocean Ridge magnetic and bathymetric survey in response to funded opportunities and the willingness of our scientific collaborators to take some risks. We later expanded that work to include hydrothermal vent discovery and survey. Today, our AUVs can perform a wide range of tasks, including near-bottom photography, in-situ chemical survey, and can map bathymetry and plume structures with high resolution. They can make rudimentary decisions on their own. We have demonstrated these capabilities outside our initial Mid-Ocean Ridge focus to include tasks like the quantification of the deep hydrocarbon plumes arising from the BP oil spill and the search for sensitive deep-sea coral sites that may have been impacted by the spill.
The future of seafloor exploration and the dual problem of under-ice survey will take elements from both ROVs and AUVs. AUVs operating with full autonomy will no doubt be applied to problems where those attributes are needed. Depending on the task and setting, untethered vehicles can also be operated under direct supervision of human operators, much like ROVs. These developments are enabled by dramatic improvements in through-water communications, including lightweight optical fiber tethers, improved acoustic communications, and through-water optical communications. The talk will conclude with speculation of how these platforms will evolve and how they will enable new areas of scientific inquiry.