A narrower passage to the sea bottom
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"When people ask me what it's like on Alvin, I tell them to pull two desks together, open the drawers, then sit underneath for seven hours with the air conditioner at full blast," says Voight, the Field Museum curator who heads to Oregon today to serve as chief scientist on a cruise where Alvin will be used to gather samples of marine life off the Oregon coast.Skip to next paragraph
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Once Alvin dives beneath the warmest layers of seawater, the outside chill seeps through the dive chamber's titanium sphere, driving temperatures inside from a mild 55 degrees F. at the start of a dive to a brisk 37 degrees at depth. The viewing ports for the pilot and for each of two scientists share very little overlap. If a geologist is scanning a cliffside, the pilot will turn the sub so he and the geologist can work together. Scientist No. 2 either watches the proceedings on a small video screen or is stuck looking out a port that stares at the black void of open ocean.
Alvin's replacement will provide the pilot and both scientists with views that overlap substantially, at best allowing for more teamwork, and at worst preventing the odd scientist out from getting too bored.
In addition, the National Science Foundation (NSF) is backing the construction of an autonomous vehicle that can span the distance between 6,500 meters, the maximum design depth for Alvin's replacement, and 11,000 meters, depths to which some of the deepest ocean trenches plunge. Compared with mid-ocean ridges, where new material wells up from deep inside the Earth to replenish the planet's crust, the deepest trenches have been harder to explore. Here, old crust plunges back into the mantle to be recycled. Scientists are eager to scoop up water and soil samples and explore and study trench walls through video links to the surface.
"That vehicle would give us our first look at some of the environments that have only been visited once by a bathysphere many years ago," says James Yoder, director of the NSF's division of ocean sciences.
Yet even with these two projects under way, researchers worry that without adequate support, ocean exploration may get shortchanged as a new generation of ocean observatories places its demands on manned and unmanned deep-sea submersibles for deployment and maintenance.
It's a lament scientists have uttered before in fields ranging from physics to astronomy. As questions become more complex, the larger and more sophisticated facilities built to answer them threaten to shoulder aside worthy but smaller-scale projects.
A first look at the intensity of the competition within marine science could emerge in Monterey Bay. There, MBARI is preparing to build a sea-floor observatory as a testbed for more ambitious projects, such as a plan to "wire" an entire crustal plate off the coast of Washington state. One point of contention: the allocation of remotely operated vehicles (ROVs).
"One of the internal debates here is how much of our ROV time is going to be taken from general users to support the sea-floor observatory," says MBARI's Robison. "We're going to learn all this stuff the hard way."
Over the past six months MBARI researchers have identified new marine species in the undersea canyon off the bay and in the Gulf of California, highlighting how little is known about the globe's largest ecosystem. "It's really staggering how much there is yet to explore," Robison says. "If we're going to ramp up that program, we're going to need vehicles to do it, and we don't have them at the moment."