Yellowstone
Net Gazette Wednesday October 15, 1997 Vol. 1 No. 3 |
||||
|
PARK
WEATHER ARCHIVES DISCUSSION FORUMS Go to Yellowstone Net Home Page Note: In-house stories are signified by the abbreviation YNET. Otherwise, the stories herein are from outside sources, to which proper credit is given. Editor Contributing |
By MICHAEL MILSTEIN YELLOWSTONE NATIONAL PARK, Wyo. - As a remote-controlled submarine probed Yellowstone Lake last summer, its sonar one day relayed an image nothing short of bizarre: a cluster of what looked like spikes in an otherwise monotonous stretch of flat lake bottom. "It was really hard to comprehend," said David Lovalvo, an electrical engineer who built and operates the small, unmanned submarine. When scientists overseeing the craft directed its expensive camera and lights toward the source of the sonar image, they made what must be one of the strangest discoveries in the history of a national park defined by strange discoveries. Jutting from the lake-bottom mud were steeple-like mineral formations, some towering 20 feet above the surrounding lake floor in water about 45 feet deep. Visibility was poor, but the submarine spotted perhaps 20 or 30 of the structures. They range in shape from broad turrets measuring more than 10 feet across, to tall narrow columns not much wider than large trees. Even in the steaming landscape of Yellowstone National Park, the submerged stone forest seems unreal. "We've never seen anything else like it," said J. Val Klump, one of a team of researchers from the University of Wisconsin at Milwaukee who have spent more than five years studying the lake with the sub's help. And the mystery runs even deeper. Geologists who have inspected small samples taken from the spires say the rock is made of the same sort of fine-grained silica found in park geyser cones. "It looks like sinters that form on land," said Pat Shanks, who conducts geochemical research for the U.S. Geological Survey. "We don't know precisely what that means." The spires lie near Bridge Bay and barely a stone's throw from the northern shore of Yellowstone Lake. They are not near any known thermal area, either in or around the lake, and the formations themselves do not appear to be ejecting warm water that could actively deposit minerals as geysers do. Even if mineral-laden hot water that once rose from the ground did slowly deposit silica to form the spires, scientists cannot understand how they ever could have been on dry land. Ancient shorelines above and below current lake waters show that Yellowstone Lake's level has varied over the past 10,000 years or more. As the slumbering volcano underlying the national park breathes and sighs, a bulge in the earth just north of Fishing Bridge has alternately lifted and dropped the outlet of the lake, varying the lake level. Geologist Kenneth Pierce of the U.S.
Geological Survey, who has studied Yellowstone's geologic history for decades, "That's almost twice as low as we know from any information we have now," Pierce said. "I can't say it didn't happen, but it's hard to imagine that it did." Even if they ever did stand dry, Pierce doubts that the spires could have gradually dropped beneath lake waters at a slow geological pace without waves and thick winter ice eroding and breaking them to bits. "I don't see how these things could have survived that kind of battering," Pierce said. "Right now, they're a big mystery." The spires bear a distant resemblance to two other tall park formations: the Liberty Cap at Mammoth Hot Springs and Soda Butte in the Lamar Valley, Shanks said. But both of those are made of calcium carbonate, a mineral very different from the silica of the spires. Tall silica cones found in the Monument Geyser Basin and an assembly of carbonate formations in a remote canyon in the eastern half of Yellowstone may more closely match the shape of the submerged spires. But neither lies underwater. Perhaps the most similar underwater features are towering "black smokers" found in volcanic zones at the ocean bottom where hot spring waters deposit sulfur compounds to form dark chimneys sometimes more than 100 feet high. But the black smokers operate at temperatures far higher than those in any Yellowstone springs, and ocean salts play a role in the chemical reactions that build the briny columns, Shanks said. In Yellowstone, on land, hot spring and geyser water builds sinter terraces and cones by slowly depositing silica. In the frigid lake, hot spring discharges carrying dissolved silica would seem at first glance to dissipate like steam. New calculations by Shanks suggest, however, that once a small mineral nozzle forms around a lake-bottom vent, it might control warm outflows enough that they could cool and deposit silica before mixing with lake water. Over hundreds or thousands of years, spires might slowly appear. Supported by the surrounding water, they could grow higher than similar formations on land. "I guess we're leaning toward thinking that they formed underwater," Shanks said. "It requires a whole new understanding of the process." Another explanation might be that hot spring
water found vertical channels through deep silt on the lake bottom and gradually deposited
sinter that came to line the channels. Changing currents in the lake might later have
washed the silt away, leaving only the sinter channels standing like The team from the University of Wisconsin had previously found such pipe-like formations on a much smaller scale generally no wider than household plumbing and under a foot long, reaching like bony fingers out of hot spots on the lake bottom. continued in next column |
"They look more like giant tree trunks," Pierce said. National Park Ranger Paul Anzalone donned an insulated dry suit before diving into lake water that was 39 degrees in midsummer to take a close look at the spires. He found them crooked and curved - some 10 feet or more in diameter at their bases, but narrowing almost to a point at the top. They looked greenish gray in the murky lake water. "You're swimming along and all of a sudden - boom, there are the spires coming out of the muddy bottom," Anzalone recalled. He and another ranger spotted about 10 to 15 spires in the 40 minutes they spent in the icy water, but the strange formations did not seem aligned in any obvious pattern, he said. They measured spires ranging from 16 to 18 feet in height. The spires were crumbly to the touch. The rangers collected a few very small samples for analysis. Shanks said he and other scientists at the U.S. Geological Survey plan to study the chemistry of the formations to learn how they compare to mineral deposits elsewhere in Yellowstone. They also will measure the ratio of oxygen isotopes in the samples, which should reveal the temperature at which they formed. And scientists will try to establish the age of the tall structures. Normal carbon-dating techniques will not work because the formations contain almost no carbon. Shanks said the Geological Survey may seek help from an expert at Argonne National Laboratories in Illinois who has developed dating techniques based on uranium instead. "It would be nice to be able to tell park visitors how these things came to be there and how special this place really is," Anzalone said. "For all we know, they may be the only ones like this in the world." By BRUCE GOURLEY BILLINGS, Mont. (YNET) - Business Owners in West Yellowstone held a rally over the weekend for the purpose of making it known to the world that Yellowstone National Park will remain open for the winter season. Rumors have been circulating that the Park will be closed, seemingly stemming from the Park's announcement of the intended closure of the Canyon to Lake snowmobile road this winter. Some observers are blaming the Park Service, when announcing the intended road closure, for not being specific enough in declaring that Yellowstone will be open for the winter in all other respects. Yellowstone in recent years has become somewhat of a magnet for controversy. The great fires of 1988 led to much criticism of the Park's policies. The continuing increase in snowmobile activity during the winter season has brought about a debate over whether or not snowmobile use should be limited. Research into Yellowstone's microbes and their subsequent cultivation and commercialization by commerical companies is fostering ongoing debate. Geothermal drilling near the Park has made headlines. The Crown Butte Mines deal currently before Congress, designed to protect Yellowstone's borders from the effects of mining, has generated much discussion during the past year. Yet, the bison slaughter of last winter has been the most controversial of all. In the midst of so much controversy, it is not surprising that rumors such as Yellowstone being closed for the winter spring forth. Indeed, various rumors about Yellowstone's demise have been circulating for several years. Rumors of Yellowstone being taken over by the United Nations and of the Park being closed for twenty years, for example, were flying around this past summer. Let it be emphatically known that such musings are totally false and are the product of someone's overactive imagination. Earlier this week some 200 people gathered for a meeting in Yellowstone to continue the celebration of the Park's 125th anniversary. As was noted at that event, Yellowstone is the "people's park." It is a public trust, an integral part of the American heritage. America has the responsibility of protecting this great treasure, while at the same time keeping it open for the citizens of America and of the world to visit and to marvel at it's never ceasing wonders. The Grand Old Park may not be able to remain immune from controversy in our modern, complex world, but this land of geysers, wildlife and rugged beauty welcomes those who would come to see her wonders.
|
||
