Most oceanographic research uses mobile short-duration platforms such as ships, aircraft, and earth-orbiting space-craft. The observations are essentially "snapshots," and are satisfactory for many investigations. There is much work, however, that requires time-series measurements over periods of months or even decades.
Recently, there has been a trend to install fixed "seafloor observatories" to meet the challenges of long-duration presence. Project Neptune is by far the largest and most ambitious of these programs. It will compete within the newly minted Ocean Observatory Initiative within the National Science Foundation. First proposed in 1988, the program's intention is "to make real-time ocean and earth studies at the scale of a tectonic plate." The Earth's surface is divided into 12-14 moving plates. Until now, there has not been a means to do lengthy time-series observations and measurements around and across an entire plate.
The problem is scale. For example, the Pacific Plate covers nearly one-third of the Earth's surface. Instrumenting this plate is not possible. Fortunately, there are smaller plates that can be wired with appropriate sensor arrays. One that meets both size and accessibility requirements is the Juan de Fuca Plate off the coasts of Oregon, Washington, and British Columbia.
Professor John Delaney, a marine geologist at the University of Washington in Seattle, chairs the Neptune team. Other program partners are the Woods Hole Oceanographic Institution, Cal Tech's Jet Propulsion Laboratory, the Monterey Bay Aquarium Research Institute, Canada's Institute for Pacific Ocean Science and Technology, and the University of Victoria in British Columbia. Numerous committees have been formed to work out the technical details and to formulate the scientific programs that will use this array. U.S. and Canadian government agencies as well as private foundations have provided start-up funding.
Two proof-of-concept installations are under construction to test various components of Neptune. The Monterey Accelerated Research System (MARS) will be a deepwater project in the Monterey Canyon. This seafloor observatory will be operational in 2005-6. The other project is the Victoria Experimental Network Under the Sea (VENUS), a shallow-water array with three cable legs extending into British Columbia's coastal waters near the Strait of Juan de Fuca. It will be operational in 2006.
Depending on the rate of funding, the Neptune array could be installed sometime in 2007-8 on the Juan de Fuca Plate. It will consist of an 1,800-mile power and fiber-optic cable network with 30 observatory stations at intervals of about 60 miles. These nodes will be along the plate's edge as well as across it in some places. Sensors will be located above, on, and beneath the seafloor. Additional sensors can be located up to 50 miles away from a node with the use of "extension cords." All connections can be made on site and underwater. Remotely operated submersibles and untethered autonomous vehicles will be resident on site for maintenance and specialized research tasks. High-resolution imaging devices combined with high-speed data transmission networks will make data available promptly to all users by way of the new high-bandwidth Internet2. The array will have at least two landfalls, in British Columbia and Oregon.
Full cost is estimated to be $250 million, which includes funding for the first five years of operations. After this time, the annual operating cost should be in the range of $10-15 million. Projected design life of the array will be 30 years.
Neptune will be flexible, able to survive in the harsh underwater environment, and different from any existing platform for research and education at sea. It will support all the fields of oceanography such as geology, biology, and chemistry. For example, biologists are interested in the rich colonies of marine life found at many places along plate boundaries. First discovered in 1977, these animals living in utter darkness appear to be rather conventional-looking fishes, shellfish, and worms. In addition, recently discovered are immense populations of heat-loving, pressure-tolerant microbes fed by the mineral-rich high-temperature fluids jetting out from the oceanic crust below the seafloor. These microbes probably were the first living things on our planet. These "extremophiles" supported by volcanoes open the question of life on other planets-one of humanity's great quests. The ambitious Project Neptune will help unlock these secrets.