The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
50 Years of Ocean Discovery: National Science Foundation 1950—2000
(including personnel) should be established for the installation and use of this equipment.
To address a wide variety of problems in marine geosciences large, portable geophysical arrays of ocean bottom seismometers, magnetometers, and electrometers will be required. Short period geophone and hydrophone instruments will be required in large numbers (e.g., 500) for both active and passive tomography experiments, and for monitoring of microseismicity in tectonic settings ranging from mid-ocean ridges to mid-plate hotspots to the accretionary wedge above a sub-ducting slab. These instruments need to be relatively inexpensive to build and operate, and should be capable of deployment times of up to a year. A smaller number (ca. 50) of portable broadband seismometers will be required for long-term teleseismic tomography studies. All of these instruments must be openly available to investigators throughout the geosciences community. Related to this is a need for shallow-water acoustic mapping instruments of high precision in order to conduct change detection experiments for capturing and quantifying dynamic seabed processes that imprint the sedimentary record. The shallow marine community could also benefit from shared pools of pressure sensors, current meters of various types, optical back-scattering devices, high resolution down-looking in situ seabed mapping tools, and the data logging and power units necessary to support such arrays.
Tethered and untethered unmanned underwater vehicles have already demonstrated their value in geophysical surveys. They extend the capabilities of conventional surface ships by expanding the area that can be monitored in both time and space and by providing close-up views of events and structures on the seafloor. Advances in technology and design now promise vehicles that are lighter, cheaper, and consume less power. In the future, cost-effective and realistic strategies for underwater event detection and temporal monitoring of systems will likely take advantage of autonomous underwater vehicles (AUVs) and remotely-operated vehicles (ROVs). It is not too soon for the scientific community to begin thinking about how to make these capabilities broadly available and how to manage such a facility. Emphasis should be placed on building some standard "bus" design that can be equipped with mission-specific sensors, without discouraging design improvements in this rapidly evolving field of ocean engineering.
Ocean Drilling Facilities
All thematic groups identified some form of ocean drilling (ODP-like) capability as a long-term requirement of their sampling and sometimes their monitoring strategies. Sampling and monitoring down-hole conditions in 100-1,000 m sections of zero-age basalts is a priority for both the solid Earth and fluids groups. The solid Earth group also needs sampling capability into older oceanic crust that may eventually require riser capability for deeper sampling. Subduction zone problems require standard ODP capability for flux balance experiments, and riser capability for investigations of the seismogenic aspects of subduction zone systems. The sediments group requires standard ODP capability in a wide variety of sedimentary environments, and in addition, a shallow-water jack-up rig capability. Deep sampling of the thick sedimentary and volcanic sequences of passive margins probably will require riser drilling capability. Paleoceanographers require hydraulic piston coring and good recovery capabilities in a wide variety of lithologies. In particular, they require improved recovery capabilities in difficult sequences such as cherts/chalks and coral.
The productivity of the entire MG&G community has been greatly enhanced since the introduction of archiving facilities for underway geophysical data and ODP cores. In contrast, there is no uniform archiving procedure for rock samples. These samples retrieved from dredging and submersible operations are a critical long-term resource with which to explore new ideas using ever more sophisticated analytical techniques. Although NSF requires samples to be made available by principal investigators after two years, there is no formal mechanism to implement this requirement, nor any clearly defined long-term repository available and accessible to the entire MG&G community. Repositories at several institutions are beginning to serve this need, but a long-term financial commitment to a sample archive would be beneficial. In addition, we need to encourage investigators to place carefully documented and packed samples into this archive.
Education and Public Relations
Public awareness and support for science, which has always been highly desirable, has become essential in the current national fiscal climate. Furthermore, the science education of the American population is an important part of NSF's federal mandate. We recommend that the Division of Ocean Sciences take a more active role in communicating the excitement of cutting edge scientific discovery to the public. It should be recognized that to be effective a sustained, focussed, long-term effort to develop the needed expertise and experience within NSF and within the science community will be required. Various models for this education and outreach activity should be examined, but one possibility is to work through a publicity office at JOI or CORE. We believe that the costs of such an effort, if it were