Seismic testing in ANWR will have major impacts

Oil drilling in the 1002 area of the Arctic National Wildlife Refuge was authorized under the 2017 Tax Reform Bill, which passed with assurances that concerns regarding impacts to the environment would be met. Under the National Environmental Protection Act (NEPA), federal agencies are required to prepare an environmental impact statement if a proposed major federal action is determined to significantly affect the quality of the environment.

In advance of the leasing program scheduled for summer 2019, the Bureau of Land Management is proposing seismic exploration of the entire coastal plain of the refuge using a 3D imaging technique to be conducted this coming winter.

Instead of a full EIS regarding proposed seismic work, BLM is planning a much-
abbreviated environmental assessment based on the assumption of "no significant impact" to the environment, an assumption I believe to be wrong based on evidence that seismic trails will have major impacts to tundra, and
pushing forward based on such an assumption would be an act of negligence of BLM's responsibility.

BLM's proposed seismic plan is seven pages, remarkably short for such a complex project. It contains no information regarding the total length of trails or total area directly impacted by the proposed seismic tracks. Nor does it include proposed locations of camps and airstrips or routes for fuel hauling. The plan is missing a realistic timeline and itinerary to carry out the survey. It contains no alternative methods that consider the destructive potential of various vehicle types, or sensitivity of different terrain and vegetation types. In past seismic surveys, trails left by camp moves have been the most damaging to the tundra, but the current plan contains no substantially different method for camp moves.

To demonstrate the density and extent of 3D seismic trails, Dr. Matt Nolan, geophysicist and owner of Fairbanks Fodar, examined recent 3D tracks just outside the western boundary of the 1002 area. One of Nolan's photos, taken in early summer 2018, shows a grid of snow-covered trails spaced at 650-foot intervals (the same density of trails proposed for the 1002 area) that contrast sharply with the snow-free areas between the tracks. The trails were also visible in photos taken in late summer 2018 after the snow melted.

Another photo, also taken in early summer 2018, from a site approximately 40 miles southwest of Prudhoe Bay, shows more detail of the pattern of trails created by 3D seismic imaging. A subset of these trails will likely persist for decades, as shown in studies from previous seismic surveys in the 1002 area and Canada.

Nolan used advanced photogrammetric methods to demonstrate that the new trails are compressed several inches below the level of the original tundra surface, providing depressions for snow, ponded water, channels for runoff,
and "thermokarst" that results when ice in the permafrost melts and causes subsidence of the ground surface.


Thermokarst is hazardous to infrastructure, causes major changes to ecosystems, and is difficult to predict or rehabilitate. Widespread new thermokarst on Alaska's North Slope has been attributed to interactions between warmer and wetter arctic climates and warmer soils associated with oilfield infrastructure. Nolan also generated an image of a seismic grid required to fully survey the entire 1002 area. The resulting "checkerboard" of tracks contains approximately 20,000 miles of trails.

The most relevant information regarding the potential impacts of seismic trails comes from a 2003 U.S. National Research Council report based mainly on information from long-term studies by the US Fish and Wildlife Service of
previous seismic trails in ANWR created in 1984–1985 showing significant surface disturbance including long-term effects to tundra vegetation and permafrost thaw that have lasted over 30 years.

Proponents of drilling predict a total full-development infrastructure footprint of 2000 acres in the 1002 Area. This estimate is not based on realistic scenarios of how the oil is distributed and where facilities will need to be located. It ignores many types of impact that will likely occur – including the impacts of ice roads, gravel roads, gravel mines, pipelines, powerlines, infrastructure-related flooding, thermokarst, road dust, and seismic trails. More realistic scenarios of development need to be presented based on current knowledge.

The 1002 area has immense value to the wildlife, the local people who depend on it for their livelihoods, and all Americans and global residents who care about this place. In order to insure proper stewardship of this important resource, I urge BLM to consider the question "Do we want to be responsible for a checkerboard of long-term impacts across the entire 1002 area?"

I urge BLM to produce a timely and reputable environmental impact statement regarding the full effects of the proposed 3D seismic program.

D.A. "Skip" Walker, Ph.D., is a professor in the Department of Biology and Wildlife at the University of Alaska Fairbanks. He serves as director of the  Alaska Geobotany Center at the university's Institute of Arctic Biology.

The views expressed here are the writer's and are not necessarily endorsed by the Anchorage Daily News, which welcomes a broad range of viewpoints. To submit a piece for consideration, email commentary(at)adn.com. Send submissions shorter than 200 words to letters@adn.com or click here to submit via any web browser. Read our full guidelines for letters and commentaries here.