The sudden appearance of a mysterious underwater crater in southern Utah has baffled scientists, UK MailOnline reported. Despite initial theories, geologists now believe it could a geologic condition called "collapsible soils" where refilling of a lake caused soil to collapse, creating a small eruption.
Discovered last month, Gary Dalton, of Circleville, spotted the unusual hole after most of the water had been drained out from the pond for irrigation. "The sun was just right," Dalton said. "So, I saw this blasted thing that no one had ever seen."
Beneath the surface, Dalton saw concentric circles in the pond bottom with a diameter of about 25ft (7.6 meters). "The outer ring is a circular depression filled with algae. An inner circle looks as though something erupted from beneath, forming what looks startlingly like a small volcanic crater," according to UK MailOnline.
Even Utah Geological Survey experts were initially left baffled by the discovery. "Well, yeah, we've got several theories," said veteran geologist Bill Lund as he examined the pond. "Most of them have gone up in smoke."
After it was speculated that the feature could have been caused by a natural spring, pushing up from under the pond after being supercharged by recent rains, the theory was quickly disproved by aerial photos that were taken before the pond was excavated two-and-a-half years ago, Lund said.
Although the Daltons saw a fiery meteor in the sky a few weeks ago, Lund has essentially ruled that out as the cause since the sighting took place long before the crater appeared.
"We don't think it's an impact crater," Lund said. "We don't think anything hit there. Obviously something came up and created this ring. But then it collapsed back on itself and closed off the vent. Whatever the vent was is closed."
Eventually a leading theory emerged about a geologic condition called collapsible soils. Since the pond has been drained and refilled more than a dozen times in the last two years, the theory predicts that the repeated loading of weight on the soil eventually led some of the soil under the pond to collapse, creating a small eruption.
"As it collapsed and compacted, it forced some air and some water up and created this thing. It looks like a one-off thing. It just happened one time. That's it," Lund explained.
Even though Lund said he has never seen such a phenomenon take place under water, that remains the most likely explanation for now. "I mean, there are still some unanswered questions here," he said. "That's for sure."
Earlier this year, a series of mysterious craters appearing in Sibera were found to have been created by methane gas, released by the thawing of frozen ground.
