Edited for brevity.
Beneath the serene surface of Yellowstone Lake, where death from hypothermia comes within 30 minutes, seethes a boiling underwater world. And like a pot too long on the stove, it could boil over, says U.S. Geological Survey geologist Lisa Morgan, Ph.D., of Colorado. She has found that temperatures along the inflated plain have been recorded at about 85 degrees 60 feet down, where the plain bulges up about 100 feet above the lake floor. (Park spokesman Cheryl Matthews says the lake rarely reaches more than 66 degrees at the surface by late summer, and is much colder deeper down.) The inflated plain stretches 2,100 feet - about the length of seven football fields - across.
"We think this is very young," something that occurred in the last few years, Morgan said. "We’re thinking this structure could be a precursor to an hydrothermal explosive event," Morgan said last week. "But we don’t think this is a volcano."
If the bulge should explode, "we think it would create a large crater." But such an explosion, smaller versions of which created Indian Pond, Duck Lake and Mary Bay itself, would probably heat up the water temporarily, create high waves, spew poison gasses and other materials into the lake for a time, and leave a rimmed underwater crater. At this point in her work, Morgan has outlined two possibilities for the plain:
It could do nothing, and "freeze in time," becoming dormant.
It could explode, making a "large crater a couple of thousand feet in diameter."
If the dome blows, 10-foot waves could wash the lake shore, rocks and pieces of lake floor could be tossed into the air, and "chemicals containing toxic materials" could be discharged into the lake. "There would be lots of water," Morgan said. Not the blue serenity of the present lake surface, but roiling, spewed-out hot water. "But we don’t think this is a volcano," Morgan said last week. Still, that possibility is being considered. She said what is causing the bulge is likely either carbon dioxide gas or steam. |