Researchers Go Off the Deep End to Learn the Secrets of Crater Lake
As a high-tech explorer begins rising through 1,500 feet of frigid water in this volcanic lake, total darkness gives way to an eerie gray glow above him.
It is the summer sunlight.
At 1,200 feet--about as deep as the Empire State Building is tall--the sun’s rays still penetrate the dazzlingly clear waters of the nation’s deepest lake.
That finding likely won’t make the scientific record books, but it was one of the wonder-filled observations made last week by the first person to dive to the bottom of Crater Lake.
“It is remarkable how much light one can detect,” said oceanographer Jack R. Dymond after he surfaced in a one-person mini-submarine, an acrylic bubble called Deep Rover. “It just goes to show how clear the water is.”
Dymond and co-investigator Robert W. Collier, both of Oregon State University, announced Sunday that they found signs but no definitive proof that geothermally heated water is rising from the lake’s floor.
The oceanographers said they saw manganese and reddish layers of iron at 1,500 feet. They suspect that hot water had deposited the minerals there as it hit the 38-degree lake water.
These preliminary findings, and a dive program that goes through Aug. 28, are being watched by principals in a burgeoning controversy over protecting the lake. The dispute has pitted environmentalists against alternative energy advocates, and has caused a conflict between two agencies in the U.S. Interior Department.
The key questions are: If geothermally heated water is rising from Crater Lake’s floor, how important is that to maintaining its famous clarity? And would the lake be damaged if wells are drilled for a geothermal power plant 7 1/2 miles east of the lake, on the edge of Crater Lake National Park?
Neither question is likely to be answered this summer. But if the reaction to previous Dymond-Collier research at the lake is any clue, varying interpretations of results from the $225,000 federally funded dive program could cause more friction between two Interior Department agencies--the National Park Service and U.S. Bureau of Land Management.
The park service manages Crater Lake and has taken the earlier research as strong evidence of hydrothermal venting that the drilling might affect. The Bureau of Land Management, which controls exploration on the land nearby, favors going ahead with the drilling and has labeled the same research biased.
At 1,932 feet, Crater Lake is the deepest lake in the United States and seventh deepest in the world. About a half-million people a year visit the lake in the southern Oregon Cascades to view its unusual cobalt-blue water, a color that results from the lake’s combination of extreme depth and unusual clarity. Unlike in shallower or dirtier lakes, virtually all light wavelengths but blues are absorbed by the water.
The six-mile-wide lake was formed after a 12,000-foot volcano erupted and then collapsed on itself about 7,000 years ago.
Very little is known about how nature maintains the lake, but scientists have detected losses of clarity in recent years. The Dymond-Collier studies are part of a 10-year program mandated by Congress to find out more about the lake so it can be protected.
Years of experience exploring oceanic hydrothermal vents underneath more than a mile of water prepared Dymond and Collier for the Crater Lake dives. But here, not only the dive target but also the vehicle differs.
In the oceans they are passengers in a cigar-shaped, three-person submersible, but the Deep Rover puts the oceanographers in the driver’s seat.
Sitting in the center of a five-foot acrylic sphere, the scientist presses his forearms against his chair’s armrests to make the submersible move. Simultaneously, his hands can work joystick-like devices that make the sub’s mechanical arms pick up rocks, take water samples and poke a temperature sensor into the lake bottom.
On Thursday morning, as Dymond prepared on the lake’s Wizard Island for his first dive, he paced with anxiety over the submersion that was to come.
“After I had checked the seals numerous times and assured myself that the seals were not leaking, I began to relax and enjoy myself,” he said.
“Sometimes I got into this groove where I could just fly and stay right on course. I didn’t even have to steer hardly.”
Once, during Friday’s dive, Dymond thought he was going to get stuck in a mud bank in a rugged area where hydrothermal venting is suspected.
“It actually took a little force to get the sub back out. I thought, ‘Gee, you could actually get stuck this way,’ ” Dymond said.
Dymond said he was awed by the topography.
“You’re driving along and all of a sudden you’ll come up against something that looms above you, and you can’t see the top. You just rise up over it. All of that has a sense of the spectacular about it.
“I spotted a large sunken tree with a two-foot-diameter trunk and 30 feet long. All the bark was intact and it was hung up on a cliff face,” he said.
Towering cliffs that never had been detected on the crater floor and a carpet of mossy plants a foot high were two surprises the scientists enountered while “flying” underwater in their crystal tub.
“The bottom at around 200 feet is completely covered with a moss that is on the order of a foot or so in height,” Dymond said. “It’s kind of a spectacular scene. It looks like a grassy field kind of moving with the current from the sub. There’s enough light down at that level to see without any sub lights, and that allows the plant life to grow.”
Although fish could be seen at shallower depths, the only indication of bottom life were small holes apparently made by burrowing worms, he said. If hydrothermal vents are found, they are unlikely to be surrounded by unusual clams and tube worms like those seen around ocean vents.
“It’s only 7,000 years (since the lake began forming), and for life to evolve to big forms is not going to be possible,” Dymond said. “We might see some bacteria.”
As Dymond and later Collier steered through the spectacular, California Energy Co. staged a spectacle of its own at the site of the proposed geothermal plant site.
The Santa Rosa company set up computer-modulated loudspeakers aimed at the park and floated helium balloons high in the air to simulate the noise and steam plume levels of an operating geothermal plant. Environmentalists have stalled the project for three years by contending that, in addition to possibly harming the lake’s water, the plant would disturb park visitors with noise and a visible plume.
