Aug. 18, 2003 – The explanation forthcoming Monday for the mysterious "vent holes" whose heated eruption spewed glass-like molten rocks in the Peterborg area several days ago places the cause on an all too common and not at all mysterious occurrence — a downed power line.
Glenn Rothgeb, Water and Power Authority chief of operations, said on Monday that a live high-voltage line went down early Friday morning on the Peterborg peninsula. And, he said, it was responsible for the geological mini-drama which began to unfold when residents discovered on Friday what they thought to be a small volcanic eruption.
They reported their discovery to various government officials and University of the Virgin Islands scientists, who converged on the scene and undertook over the weekend to analyze the phenomenon and its cause. (See "Investigations will continue into melted rock".)
A downed power line is not an unusual situation in the Virgin Islands. How did this one have such unusual results?
Irvin Francis, WAPA assistant line superintendent, said Monday afternoon that when a 7,050 voltage high voltage power line hits rock, the rock melts. "That's exactly what did it," he said. "The power line hit the rock and was dancing on it when we got there. It caused the rock to melt like it actually was cut."
Francis said he has until now "never experienced a rock burn like that. It's almost like the electricity is magnetized."
WAPA got a call from 911 about 12:27 a.m. Friday, Francis said, and the company's emergency standby crew went to the site immediately and found the wire on the ground. He said it would have been time-consuming to pull all the fuses from the power pole to get the current off, so they called the power plant and asked to have the feeder interrupted.
Francis, a Peterborg resident, said first-class lineman Kenval Thomas and apprentice lineman Denzel Dawkins were the first on the scene. He did not know who put in the initial call to 911, but there are frequent police patrols in the area, he said.
He said the problem with the downed power line was corrosion — a condition he described as common to many of the lines on the North Side. "In fact, we had planned to go into that area this week to change transformers and do maintenance work on the lines," he said.
In the scientific community, some speculation exists still about the cause. UVI physicist Roy Wattlington said he had contacted Haraldur Sigurdsson, a vulcanologist at the University of Rhode Island. Sigurdsson is scientifically familiar with the Virgin Islands area and has lectured on St. Thomas and St. John. In March, he headed a comprehensive study of the submarine volcano named Kick 'em Jenny off Grenada, accompanied by members of the UVI Center for Marine and Environmental Sciences.
Sigurdsson said it is "entirely feasible" that a lightening strike could have produced the strange phenomenon and could create the glass-like rocks known as fulgarites.
He told Wattlington in an e-mail, "You have a very interesting find. I think this is almost certainly a fulgarite, which is the result of a large lightning strike on a rock surface."
Wattlington said: "We are satisfied that man-made power or natural lightning is the actual culprit, but I'd be interested in hearing more. The scientific interest in it is great."
Wattlington questioned whether a line carrying 7,000 to 8,000 volts of electricity could have melted the rocks.
One scientist at the scene said he didn't detect a distinct "sulphurous" smell, as had been reported by those initially discovering the molten rocks. He suggested that the mystery might have activated the olfactory imagination in some observers.
Peterborg residents offered no support for the lightning theory.
Resident Jared Falek said he had no recollection of any storms last week. "I am really sensitive to the fact that we've had no rain," he said.
William Newbold said he, too, thought it had been very dry and didn't remember there having been stormy weather "of any consequence" for over a week.
Businessman Hurdle "Trip" Lea said: "The minute I heard about it, I knew exactly what it was."
Lea said he had seen the damage from a "hot line" from a power pole that had lain on the ground near a home in North Carolina. "The rocks were almost identical to the ones pictured on the Source," he said.
In the case of the downed line in North Carolina, Lea said, it had lain on the ground "arcing" for about seven hours before the power was turned off.
The hot lines "melted dirt and sand into glass," he said.
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