PRUDHOE BAY, Alaska (AP) -- New technology is being used to search for untapped oil in an Alaska bay that is already an established source of fossil fuel, according to officials.
Oil and gas company BP is employing "3D seismic" technology to locate small pockets of previously undiscovered oil in Prudhoe Bay in northern Alaska, the Fairbanks Daily News-Miner reported Saturday.
The area has been an oil source for more than four decades, but in recent years its flow has slowed, the newspaper reported.
The technology involves metal platforms mounted to "vibe trucks" weighing about 93,000 pounds (42,185 kilograms) that cause the ground to vibrate with sonic energy, officials said.
"As the energy wave goes through the subsurface, the rocks are in layers, and the layers are based in hardness," said Robert Pool, a BP seismic acquisition specialist. "A harder layer, the sound wave goes through faster. And a softer layer, it goes through slower."
Receivers pick up the returning sound waves and convert the data into a three-dimensional "cube" depicting the geology below, including the location of hidden pockets of oil, officials said.
The 3D seismic survey from January through mid-April will sweep over 450 square miles (about 1,166 square kilometers), the company said.
Environmental groups have voiced strong opposition to prospective 3D seismic work in the Arctic National Wildlife Refuge, but they have not opposed BP's use of the technology in Prudhoe Bay, the newspaper reported.
Alaska only allows seismic work when the tundra is frozen and covered with snow, while federal authorization is required because the bay is a polar bear habitat, officials said.