Mid-Cayman Rise objectives were built on exciting results from a flurry of recent expeditions that investigated hydrothermal sites in the region (German et al., 2010, 2012). The 2013 E/V Nautilus cruise explored oceanic core complexes (OCCs), tall, smooth-sided hills that rise from the seafloor on the flanks of some mid-ocean ridges. Dives (Figure 1) explored the full extent and nature of life around the Von Damm hydrothermal field, previously discovered there, as well as the geology to further understanding of the vents’ origins, and to survey the OCC summits that had never before been investigated by a deep diving vehicle. This 2013 study was the first Nautilus cruise to have more scientists participating in the expedition from locations on shore than from the ship, tripling the size of the science party.
Over the last couple of decades, funding agencies have increased pressure on scientists to demonstrate that their research has some societal benefit. When the National Science Foundation established the Broader Impacts requirement (NSF, 1997) by merging two review criteria—utility or relevance of the project and its effect on the infrastructure of science and engineering—principal investigators largely ignored it (Lok, 2010). Then, in 2002, NSF began to return (without review) any proposal that didn’t explicitly address broader impacts (NSF, 2002).
Deep biosphere research has grown so quickly over the last several decades, it’s enough to make a fast-growing microbe jealous. Biological characterization of the diversity and function of life in the ocean crust first moved into a prominent role in the drilling program with ODP Leg 201. Recently, however, it has been the main focus of several expeditions, including 329 (South Pacific Gyre Subseafloor Life) and 336 (Mid-Atlantic Ridge Microbiology) on board the JOIDES Resolution, and 337 (Deep Coalbed Biosphere off Shimokita) on board the Chikyu. With these, and through microbiological work on other expeditions, the deep biosphere research community is finding its stride. Moreover, new deep biosphere-focused research programs such as the Center for Dark Energy Biosphere Investigations (C-DEBI) are enabling new colleagues to get involved in this fast moving field.
Since 1981, Robert Ballard has envisioned a concept of ocean exploration with multiple ships collecting video and data from the depths of the world ocean and broadcasting discoveries in real time through ship-to-shore satellite technology. In 1989, the telepresence vision was realized when the first Jason Project broadcasts employed ROV technology developed by the Deep Submergence Laboratory at Woods Hole Oceanographic Institution (WHOI). Those early telepresence-enabled broadcasts delivered live educational programming to vast audiences who could participate in the exploration as it was happening.
Articles in this special issue of Oceanography represent a compendium of research that spans the disciplinary and thematic breadth of the National Science Foundation’s Ridge 2000 Program, as well as its geographic focal points. The mid-ocean ridge (MOR) crest is where much of Earth’s volcanism is focused and where most submarine volcanic activity occurs. If we could look down from space at our planet with the ocean drained, the MOR’s topography and shape, along with its intervening fracture zones, would resemble the seams on a baseball, with the ocean basins dominating our planetary panorama. The volcanic seafloor is hidden beneath the green-blue waters of the world’s ocean, yet therein lie fundamental clues to how our planet works and has evolved over billions of years, something that was not clearly understood 65 years ago—witness the following quote from H.H. Hess (1962) in his essay on “geopoetry” and commentary on J.H.F. Umbgrove’s (1947) comprehensive summary of Earth and ocean history:
The birth of the oceans is a matter of conjecture, the subsequent history is obscure, and the present structure is just beginning to be understood. Fascinating speculation on these subjects has been plentiful, but not much of it predating the last decade [the 1950s] holds water.
Submarine volcanic eruptions and intrusions construct new oceanic crust and build long chains of volcanic islands and vast submarine plateaus. Magmatic events are a primary agent for the transfer of heat, chemicals, and even microbes from the crust to the ocean, but the processes that control these transfers are poorly understood. The 1980s discovery that mid-ocean ridge eruptions are often associated with brief releases of immense volumes of hot fluids (“event plumes”) spurred interest in methods for detecting the onset of eruptions or intrusions and for rapidly organizing seagoing response efforts. Since then, some 35 magmatic events have been recognized and responded to on mid-ocean ridges and at seamounts in both volcanic arc and intraplate settings. Field responses at mid-ocean ridges have found that event plumes occur over a wide range of eruption styles and sizes, and thus may be a common consequence of ridge eruptions. The source(s) of event plume fluids are still debated. Eruptions detected at ridges generally have high effusion rates and short durations (hours to days), whereas field responses at arc volcanic cones have found eruptions with very low effusion rates and durations on the scale of years. New approaches to the study of submarine magmatic events include the development of autonomous vehicles for detection and response, and the establishment of permanent seafloor observatories at likely future eruption sites.