Next Wave of Oceanic Research
Scientists use remote sensors to identify underwater earthquake damage off California coast. MARINE ECOLOGY
| PACIFIC GROVE, CALIF.
IN a darkened room of the Point Lobos, a research ship on Northern California's Monterey Bay, a marine biologist and two geologists scrutinize a video monitor. All morning, the ship has crossed the Monterey Canyon, a gaping breach in the continental shelf similar in size to the Grand Canyon. Now a video camera, almost 300 feet below, transmits pictures of an underwater landslide or ``slump'' that has occurred on the canyon wall.
The scientists are excited. Although swirling debris from the loose wall often occludes the images, these are almost certainly the first pictures ever taken of a marine canyon slump soon after a major earthquake - in this case, the 7.1 temblor that shook the San Francisco region in October.
``The Monterey Canyon provides an opportunity to study a well-represented area on the earth's surface - cold, deep water - very close to home,'' says Chuck Baxter, a biologist from the Monterey Bay Aquarium Research Institute (MBARI), which owns the ship. ``We can get to this terrain 10 nautical miles from our dock, as opposed to 100 miles or so on the East Coast. We are taking some of the highest-quality deep sea images in the world.''
The live images are not only shown on three different screens in the control room, but simultaneously in MBARI's offices on shore. Every minute is recorded on broadcast-quality videotape, narrated on the spot by the oceanographers aboard.
``Usually, it would take me a month just to apply for a boat, and actual research wouldn't take place until many weeks later,'' says Gary Greene, a marine geologist with the United States Geological Survey and Moss Landing Marine Labs. ``This excursion is a good example of what a private foundation can do,'' Mr. Greene says.
The newest of five research organizations in the Monterey Bay region, MBARI operates on a multimillion-dollar grant from the David and Lucile Packard Foundation based in Los Altos, Calif.
The institute's mandate is ``establishing a system concept for the ecology of Monterey Bay.'' Through observation and measurements, researchers will try to determine how the mix of sun and wind, phytoplankton and marine animals, topography and ocean currents, work together.
With its long-term funding, MBARI is free to pursue long-range goals while encouraging collaboration, not competition, among scientists in related fields.
``Oceanographers vie for funding from just two major sources: the National Science Foundation and the Office of Naval Research,'' says Dick Barber, executive director of MBARI. ``While this system rewards creative, aggressive individuals with three-year grants, it has discouraged interdisciplinary work and long-term thinking.''
Mr. Barber says a long-term study of an oceanic ecosystem is overdue, pointing out that humankind is modifying, if not abusing, a terrain that represents two-thirds of the earth's surface. Scientists have little information on how oceans operate. Whether the issue is global warming or ocean dumping, they don't know enough to accurately forecast the consequences.
``Being terrestrial animals, we have a much better understanding of how terrestrial systems work,'' says Barber. ``But in the ocean, we don't have that expertise. The US maintains only about 10 buoys on both coasts, and they report wind and wave conditions, but no subsurface ocean properties. Because we look closely at oceanic ecosystems for just short periods, we have only an abstract notion of how these systems operate.''
Other scientists agree. ``Right now, the few long-term data we have are from fisheries, which have recorded fluctuations in stock. But MBARI is fairly unique in that it is studying an entire ecosystem,'' says Mike Reeve, head of the Ocean Sciences Research Section of the National Science Foundation.
``We know, for example, that global warming from increased carbon dioxide emissions can potentially raise sea levels, change ocean currents, and even dramatically redistribute weather patterns,'' he says. ``But only by looking at an oceanic ecosystem in great detail over many years can we sort out genuine long-term trends from mere statistical noise.''
ABOARD the Point Lobos, the first thing that strikes a visitor is the remotely operated vehicle, or ROV, perched on its deck. With its tangle of wires, mechanical arm, and video camera lens peering out the front, the ROV looks like a creation of George Lucas.
``The problem with studying the ocean is two-fold: We have difficulty staying there and trouble getting deep,'' Mr. Barber says. ``Both can be addressed by remote-sensing devices. As the Alvin project at Woods Hole Oceanographic Institution has proven, sending people down in submersibles is certainly possible and worthwhile, but also very difficult and expensive. We think it's better over the long term to learn about the ocean by deploying sensors to be our eyes and ears.''
On this November morning, MBARI scientist Baxter is accompanied by two marine geologists, Greene and colleague Mike Ledbetter, who have more than a professional interest in locating underwater slumps. Both have associations with Moss Landing Marine Labs, which was built on a spit at the head of Monterey Canyon. The California earthquake opened a six-inch crack in the floor of that facility, large enough to reach in and scoop out sand. The geologists theorize that the seismic activity that condemned the buildings has also taken place further down the canyon walls.
The first order of business is to locate a probable area where slumps might have occurred. To do this, the ship slowly traverses the canyon with a series of one-mile sweeps. On the bridge, the three researchers and the first mate stare intently at an instrument called a bathymetric profiler. The device plots the profile of the ocean floor by emitting high-frequency sounds and gauging the depth by their echo. As we crisscross the channel, a series of deep arches is plotted on the paper, and the geologists look for slight irregularities that may indicate a landslide.
After several hours of searching, the researchers agree on a spot. Technicians unlash the ROV and deploy it with a crane. The ROV is linked to the boat with a long tether containing electric cords and fiber-optic cables for sending images. A pilot controls it from the ship's control center using a joy stick - a more elaborate version of the device used on video games.
For several hours, there is no sign of a slump. Buffed relentlessly by the current, the canyon wall has the uniform texture of carpet. But in the midafternoon, we come across an area that has clearly slid. Clouds of small fish swirl above, attracted by the newly exposed nutrients.
``This is living geology,'' says Greene. ``We're used to thinking in terms of eons, but here is activity that has taken place over the past few weeks. We can't absolutely say that it's related to the earthquake, but it's a good working assumption.''
THE voyages of the Point Lobos are the most visible part of MBARI's activities, but the task of making the data it collects available to researchers will be its legacy. Barber notes that science, in general, has become very good at gathering data, but less successful at making them accessible.
``For example, from 1979 through 1986, a satellite sensor called the Coastal Zone Color Scanner took magnificent pictures of the ocean - with results a hundred times better than expected,'' he explains. ``But we are only now getting around to making those images available to researchers. A similar thing happened with Alvin, the manned submersible that revolutionized deep-sea biology. We now have thousands of wonderful pictures, but no central index to them.
``We're very much a second-generation research organization. For us, collecting data is just the beginning. The big job is to turn that data into information, indexing it so that people can readily retrieve it.''
At MBARI, the process is only beginning to take shape. It starts with Lynn Lewis, who annotates each videotape based on areas of interest for the researchers. This information is then entered into a computer database, where it can be correlated with sensor and location data.
``How do we help scientists handle massive amounts of data in a meaningful way?'' asks Bruce Gritton, MBARI information specialist. He envisions a flexible computer system that will enable researchers to recall pictures, sounds, sensor data, and the interpretation of that data using a wide variety of criteria.
``We are not explorers,'' says Barber. ``We are the next generation and the task before us is to understand how things work. Our aim is to stay in the deep-sea environment long enough to take pictures of an animal throughout the seasons - then make this data available to scientists not yet born, and answer questions not yet framed.''