The announcement signals at least a temporary victory for environmental groups and scientists who oppose the project, in which large trucks and other heavy equipment would crisscross the refuge’s coastal plain along the Arctic Ocean, using acoustic signals to map underground rock formations that may hold oil and gas reserves.
Steve Wackowski, the department’s senior adviser for Alaska affairs, made the announcement at a hearing Tuesday in Kaktovik, a village within the refuge.
Faith Vander Voort, a department spokeswoman, said the seismic proposal was still pending, and that the company behind it, SAExploration, had asked that the start date be moved to next December.
The postponement will have no direct impact on the Interior Department’s plan to open the coastal plain, 1.5 million acres known as the 1002 Area, to oil and gas development. The department, through the Bureau of Land Management, has said it wants to offer leases for sale this year.
The coastal plain is thought to overlie formations containing billions of barrels of oil, and the Trump administration has been eager to allow development, part of its push for more commercial activities on federal lands.
But the decision means that oil companies that bid on the leases will have to do so without the benefit of new data on potential reserves. The only seismic studies in the refuge were done three decades ago, using less-effective technology. An exploratory well, the only one in the refuge, was drilled around the same time, and its results have remained secret.
Opponents of the seismic plan have argued that the work would harm polar bears and other wildlife and leave indelible scars on the delicate tundra in the refuge, a vast, largely unspoiled wilderness in the northeastern part of the state.
But the Bureau of Land Management and SAExploration have said that new seismic technology has little permanent impact on the landscape. The company says it is working with federal wildlife officials on steps to be taken to minimize harm to wildlife.
The seismic project is a joint venture with two Alaska Native corporations. Officials from SAExploration could not be reached for comment.
The Sierra Club — which, with members of the Gwich’in community, Native Alaskans who live near the refuge, had organized a campaign to oppose the seismic work — hailed the decision. “This is a major victory in the fight to protect this special and sacred place,” Michael Brune, the Sierra Club’s executive director, said in a statement. “We will not back down until it is permanently protected.”
Democrats have blocked proposals to open the refuge for decades, but in 2017, the Trump administration and Republicans in Congress approved a plan to allow oil and gas development there. A draft environmental impact statement on the leasing plan was issued in December and is expected to be finalized this year, allowing the sales to proceed.
Separately, last spring, SAExploration filed its proposal and aimed to have trucks rolling into the refuge by late last year. The work can only be done in winter, when there is sufficient snow cover to allow travel on the tundra.
The Bureau of Land Management conducted an environmental assessment of the proposed project — a less rigorous evaluation than an environmental impact statement — and another Interior agency, the U.S. Fish and Wildlife Service, worked with the company on regulating how much disturbance or harm to wildlife would be allowed.
All that work has taken longer than expected, however. The assessment and the regulations have not been made public, which means the seismic work could not have begun until mid-March at the earliest. That would have left two months or less for the work before the snow disappeared.
The decision was first reported by KTOO Public Media in Alaska.
Environmentalists and scientists had criticized the Bureau of Land Management for refraining from a more rigorous appraisal of the potential impact of the seismic work.
The critics argued that under the National Environmental Policy Act, the umbrella legislation that governs environmental reviews, the effects of seismic studies on the tundra and wildlife could be enough to warrant a fuller environmental impact statement, especially considering the significance of the refuge.
The Bureau of Land Management said there had been previous thorough environmental studies of the refuge. Because the seismic assessment could make use of those, a more rigorous evaluation was not needed, it said.
Critics said they were especially concerned about the harm that could be done to the southern Beaufort Sea subpopulation of polar bears, which has been declining in numbers as climate change has reduced sea ice in the region. More of the bears are making winter dens — in which pregnant females give birth to cubs — in snow drifts on the coastal plain.
Steven C. Amstrup, chief scientist of the conservation group Polar Bears International, said the risk to the bears was that seismic trucks, which weigh up to 45 tons, could come close to or ride over dens, forcing the bears outside prematurely or even injuring or killing them.
The Bureau of Land Management said precautions would be taken to identify and avoid dens, including the use of infrared sensing that can detect the warm bears in their frigid surroundings.
But Amstrup said his research showed that such techniques would not detect all dens. The seismic work, he said, “has the potential of impacting 50 percent of dens in the most important denning area.”
SAExploration’s proposal calls for trucks to roll across the tundra in grid lines roughly 200 yards apart, sending acoustic signals deep into the earth to assess the location of any oil or gas deposits.
The trucks have rubber caterpillar treads designed to minimize the impact on the fragile landscape. They would be accompanied by two “man camps” holding up to 160 workers each, along with fuel tanks and other equipment for the work.
Opponents have said that even with the steps taken to minimize damage, the seismic work could have lasting effects on the fragile landscape, compressing the tundra and potentially altering vegetation types and the flow of water.
They point out that there are still signs of the seismic work undertaken in the area in the mid-1980s. And work by a Fairbanks-based digital mapping expert last summer found evidence of damage by seismic trucks that operated just west of the refuge in April.
This article originally appeared in The New York Times.