Responding to arctic oil spills

Arctic oil spill

[ It is insane to even contemplate putting oil rigs into an area with such vast amounts of ice on the move, and all the additional dangers listed below.  Before I read this 210 page NRC report, I thought the main problem was ice bergs, but there is a lot more to worry about.

No wonder there’s little to no drilling going now.  It’s too expensive to keep oil rigs and tankers from being punctured or tipped over. Shell gave up on it and has abandoned plans to develop the arctic in the near future. 

Even if an oil company wanted to drill, there’s just 1 to 3 months in the summer to drill one well.  If oil is found, dozens more need to be drilled to see if the extent of the field is worth going after. And to get it out, new infrastructure: roads, pipelines, ports, and so on. It would take decades to do that before the first drop of oil could be produced.   Yet the arctic is where a quarter of the remaining oil and gas are.  But even desperation may never make it possible to drill in the Arctic given all the barriers listed below, and will be an ecological disaster if it’s attempted.

Alice Friedemann   www.energyskeptic.com  author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts:  KunstlerCast 253, KunstlerCast278, Peak Prosperity]

NRC. 2014. Responding to Oil Spills in the U.S. Arctic Marine Environment. National Research Council, National Academies Press. 211 pages

Examples of Risks Associated with Oil Spill Response Due to Weather Conditions

Adverse weather conditions can have impacts on the feasibility of oil spill response, especially in relation to marine and airborne operations

Sustained wind speeds greater than 25 knots (~13 m/s) could

  1. Hinder crane operations and equipment use on response vessels, with a possibility of swinging or uncontrollable loads;
  2. Limit in situ burning, as a typical wind threshold for successful burn operations is 20 kt (~10 m/s) or less;
  3. Limit surface dispersant application from vessels and aircraft;
  4. Limit mechanical recovery operations, such as skimmer deployment and boom containment
  5. Hamper small boat operations due to the potential for severe sea states, breaking waves, and superstructure icing;
  6. Hinder helicopter approach and landing on offshore helidecks.

Sea states greater than 1-1.5 m could

  1. Limit boom effectiveness, as wave overtopping leads to loss of contained oil;
  2. Impede small boat operation, due to waves, wind, and icing potential;
  3. Contribute to seasickness and/or fatigue, impacting personal safety and effectiveness;
  4. Jeopardize safety on deck from slippery and icy surfaces.

Visibility that is less than visual flight rules or instrument flight rule minimums (due to weather or season) could

  1. Limit helicopter landings when cloud ceilings or visibility are below minimum standards set by the
  2. Federal Aviation Administration or company policy
  3. Curtail aerial dispersant spraying;
  4. Limit oil spill monitoring by preventing direct visual observations.

Extreme cold temperatures (less than −35°C) could

  1. Impact safety on deck, due to effects from wind chill;
  2. Impact responder safety because of potential for frostbite;
  3. Decrease worker efficiency from fatigue, leading to a need for frequent rest breaks;
  4. Contribute to equipment breakdown due to changes in oil viscosity, hydraulic leaks, or mechanical failure
  5. Limit helicopter operations, which have a lowest acceptable operating temperature set by operators and manufacturers

The lack of infrastructure in the Arctic would be a significant liability in the event of a large oil spill. Communities are dependent on air and seasonal marine transport for the movement of people, goods, and services, and there are few equipment caches with boom, dispersants, and in situ burn materials available for the North Slope and Northwest Arctic Boroughs. It is unlikely that responders could quickly react to an oil spill unless there were improved port and air access, stronger supply chains, and increased capacity to handle equipment, supplies, and personnel. Prepositioning a suite of response equipment throughout the Arctic, including aerial in situ burn and dispersant capability, would provide immediate access to a number of rapid response oil spill countermeasure options.

Frequent winter breakaway events can substantially alter the extent of fast ice along the Chukchi Sea coast in a matter of hours, as floes that can be several kilometers across fracture and drift out into open water stretches. In early winter, the fast ice remains unstable right into the coast until December and occupies a limited extent compared to the Beaufort Sea.

Other infrastructure

Commercial infrastructure is either limited or absent in the U.S. Arctic. Oilfields around Prudhoe Bay host support service contractors and their equipment. In the event of a SONS and the necessity for rapid deployment of large numbers of responders, passenger jet service (737-scale) is available at Nome, Kotzebue, Barrow, and Deadhorse (Figure 4.3). Smaller aircraft service (19-passenger turboprop) can access nearly all of the approximately 30 coastal communities and other developments (e.g., Red Dog Mine, De Long Mountains Terminal) from Nome to the Canadian border. Almost all of the airstrips can be accessed by C-130 and smaller cargo aircraft if needed for rapid deployment of spill response equipment. Multiple heavy lift aircraft would be needed to bring in capping stack equipment.

Spill responders and other personnel would find a severe shortage of housing, fresh water, food and catering, sewage handling and garbage removal facilities, communications infrastructure, ability to handle heavy equipment, supplies, and hospitals and medical support. Large numbers of response workers also represent an increased risk of accidents and injuries. There are also limited bandwidth and communications capabilities. A single fiber optic cable connects the existing oil fields and there are currently no cables to northwestern Alaska, although a hybrid of fiber optic and microwave repeater towers are planned for the Northwest Arctic Borough. Increased bandwidth capacity is needed to share data and information in the event of an oil spill.

Moreover, recovered oil and oily debris must be collected and disposed of in predesignated locations, or the means to transport the material to some approved location outside of the local area is needed. Given the limited highway infrastructure, planners will inevitably look to aviation and seaborne support for all of these needs. There are no deepwater ports in the two boroughs. Nome has a shallow water port with docks, while other villages have shallow embayments (0-20 ft) without support facilities. The distance from Dutch Harbor, the closest full-service port, to the Shell drilling site in the Chukchi Sea, for example, is approximately 1,600 km. Sea-based support will be limited in its ability to work very close to the shore, due to shallow waters in much of the region, so a contingent of shallow water craft is needed for nearshore operations. Most of this can be contracted commercially, provided through government or military sources (if available), or provided on station by the operator and ready for immediate use. This latter approach was followed by Shell during its 2012 season. Absent this approach, the time delay in bringing adequate capabilities to the scene could be significant.

The absence of infrastructure in the U.S. Arctic would be a significant liability in the event of a large oil spill. It limits the ability to conduct routine operations and maintenance, engage local communities, and develop meaningful area familiarity. There is presently no funding mechanism to provide for development, deployment, and maintenance of temporary and permanent infrastructure.

Effective oil spill response requires improved communication bandwidth and networks; transportation systems; environmental and traffic monitoring systems; energy and fuel systems; personnel, berthing, housing, waste and medical support facilities; as well as civil infrastructure development to provide improved port and air access to remote locations using extended supply chains and an increased capacity to handle equipment, supplies, support, and personnel.

Summary

The Arctic system serves as an integrator for the Earth’s physical, biological, oceanic, and atmospheric processes, with impacts beyond the Arctic itself. The risk of an oil spill in the Arctic presents hazards for Arctic nations and their neighbors. The threat of a major Arctic oil spill and the potential impacts on the region’s marine ecosystems are of concern for a broad range of U.S. and international interests, including Alaskan natives and others who live in the region, citizens and organizations concerned about the health of the Arctic environment, agencies committed to protecting the environment and threatened species, agencies that regulate extractive activities or transportation, and industries that plan to develop oil and gas, shipping routes, fisheries, or tourism.

Rapid climate change is leading to retreat and thinning of Arctic sea ice, potentially increasing the accessibility of U.S. Arctic marine waters for commercial activities. With this projected rise in activity come additional concerns about the risk of oil spills. Recent interest in developing the rich oil and gas resources in federal waters offshore of Alaska has led to planning, environmental assessments, and preliminary drilling for oil and gas exploration. In addition, expanding maritime activity in the region includes the potential for greater seasonal use by tankers and bulk carriers, fishing fleets that follow the northward migration of fish stocks, and cruise ships interested in exploiting the public’s desire to interact with Arctic wilderness.

Arctic oil spill response is challenging because of extreme weather and environmental conditions; the lack of existing or sustained communications, logistical, and information infrastructure; significant geographic distances; and vulnerability of Arctic species, ecosystems, and cultures.

A fundamental understanding of the dynamic Arctic region is needed to help guide oil spill response and recovery efforts. Information on physical processes—including ocean circulation, ice cover, marine weather, and coastal processes—is important to frame the environmental context for the Arctic ecosystem and can help responders predict where oil will spread and how weathering might change its properties. Parameters such as air and water temperature, wind velocity, and hours of daylight are important considerations in choosing an effective and safe response strategy.

Knowledge of ice thickness, concentration, and extent is essential for anticipating the likely behavior of oil in, under, and on ice and determining applicable response strategies, while high-quality bathymetry, nautical charting, and shoreline mapping data are needed for marine traffic management and oil spill response. From a biological perspective, understanding population dynamics and interconnections within the Arctic food web will enable the determination of key species that are most important for monitoring in the instance of an oil spill.

Baseline data are critical to assess changes over time. In the Arctic, historical data do not provide reliable baselines to assess current environmental or ecosystem states, nor can they fully anticipate potential impacts due to factors such as seasonal and interannual variations or climate change. Instead, monitoring approaches will need to take advantage of benchmarks, or reference points over time, rather than static baselines.

Critical types of benchmark data for oil spill response in the Arctic include: • Spatial and temporal distributions and abundances for fishes, birds, and marine mammals; • Subsistence and cultural use of living marine resources; • Identification and monitoring of areas of biological significance; • Rates of change for key species; • Sensitivity of key Arctic species to hydrocarbons; • High-resolution coastal topography and shelf bathymetry; and • Measurements of ice cover, thickness, and distribution.

Additional research and development needs include meteorological-ocean-ice forecast model systems at high temporal and spatial resolutions and better assimilation of traditional knowledge of sea state and ice behavior into forecasting models. Releasing proprietary monitoring data from exploration activities would increase knowledge of Arctic benchmark conditions. When appropriate, Arctic communities could also release data that they hold regarding important sites for fishing, hunting, and cultural activities.

In many instances, frequent and regular long-term monitoring will be needed to determine trends. Because data are or will be collected by a number of local, state, and federal agencies, as well as industry and academia, a complete information system that integrates Arctic data in support of oil spill preparedness, response, and restoration and rehabilitation is needed. Achieving this goal requires the development of international standards for Arctic data collection, sharing, and integration. A long-term, community-based, multiuse Arctic observing system could provide critical data at a variety of scales.

Recommendation: A real-time Arctic oceanographic-ice-meteorological forecasting system is needed to account for variations in sea ice coverage and thickness and should include patterns of ice movement, ice type, sea state, ocean stratification and circulation, storm surge, and improved resolution in areas of potential risk. Such a system requires robust, sustainable, and effective acquisition of relevant observational data.

Recommendation: High-resolution satellite and airborne imagery needs to be coupled with up-to-date high-resolution digital elevation models and updated regularly to capture the dynamic, rapidly changing U.S. Arctic coastline. Nearshore bathymetry and topography should be collected at a scale appropriate for accurate modeling of coastline vulnerability and storm surge sensitivity. Short- and long-term Arctic nautical charting and shoreline mapping that have been identified in NOAA and U.S. Geological Survey plans should be adequately resourced, so that mapping efforts can be initiated, continued, and completed in timescales relevant to anticipated changes. To be effective, Arctic mapping priorities should continue to be developed in consultation with stakeholders and industry and should be implemented systematically rather than through surveys of opportunity.

OIL SPILL RESPONSE RESEARCH

A comprehensive, collaborative, long-term Arctic oil spill research and development program that integrates all knowledgeable sectors and focuses on oil behavior, response technologies, and controlled field releases is needed.

Laboratory experiments, field research, and practical experience gained from responding to past oil spills have built a strong body of knowledge on oil properties and oil spill response techniques. However, much of the work has been done for temperate regions, and there are areas where additional research is needed to make informed decisions about the most effective response strategies for different Arctic situations. In the presence of lower water temperatures or sea ice, the processes that control oil weathering—such as spreading, evaporation, photo-oxidation, emulsification, and natural dispersion—are slowed down or eliminated for extended periods of time. Because of encapsulation of oil by new ice growth, oil can also be separated from the environment for months at a time. Understanding how oil behaves or changes in the Arctic environment can help define the most effective oil spill response actions. In addition to ongoing research on oil properties and weathering in high latitudes, there is a need to validate current and emerging oil spill response technologies on operational scales under realistic environmental conditions. Carefully planned and controlled field releases of oil in the U.S. Arctic would improve the understanding of oil behavior in the Bering Strait and Beaufort and Chukchi Seas and allow for the evaluation of new response strategies specific to the region. Scientific field releases that have been conducted elsewhere in the Arctic demonstrate that such studies can be carried out without measureable harm to the environment.

Recommendation: A comprehensive, collaborative, long-term Arctic oil spill research and development program needs to be established. The program should focus on understanding oil spill behavior in the Arctic marine environment, including the relationship between oil and sea ice formation, transport, and fate. It should include assessment of oil spill response technologies and logistics, improvements to forecasting models and associated data needs, and controlled field releases under realistic conditions for research purposes. Industry, academic, government, non-governmental, grassroots, and international efforts should be integrated into the program, with a focus on peer review and transparency. An interagency permit approval process that will enable researchers to plan and execute deliberate releases in U.S. waters is also needed.

Oil spill countermeasures

Key response countermeasures and tools for oil removal in Arctic conditions include biodegradation (including oil treated with dispersants), in situ burning, chemical herders, mechanical containment and recovery, detection and tracking, and oil spill trajectory modeling. These are joined by the “no response” option of natural recovery, which is a viable alternative in some situations. No single technique will apply in all situations. The oil spill response toolbox requires flexibility to evaluate and apply multiple response options, if necessary. Well-defined and well-tested decision processes are critical to expedite review and approval of countermeasure options in emergency situations.

Recommendation: Dispersant pre-authorization in Alaska should be based on sound science, including research on fates and effects of chemically dispersed oil in the Arctic environment, experiments using oils that are representative of those in the Arctic, toxicity tests of chemically dispersed oil at realistic concentrations and exposures, and the use of representative microbial and lower-trophic benthic and pelagic Arctic species at appropriate temperatures and salinities.

In Situ Burning is a viable spill response countermeasure in the Arctic. Ice can often provide a natural barrier to maintain the necessary oil thicknesses for ignition, without the need for booms. With relatively fresh oil that is wind herded against an ice edge, or collects in melt pools in the spring, removal efficiencies in excess of 90% are achievable through in situ burning. However, in very open drift ice conditions, oil spills can rapidly spread too thinly to ignite. To improve the limits of in situ burning, further research is needed to evaluate improved ignition methods and to explore the use of aerially applied oil-herding chemicals at different spatial scales and with different oil types, including weathered states.

Mechanical containment and recovery removes oil from the marine environment, rather than adding chemicals or generating burn residue. However, when dealing with large offshore spills, the oil can quickly spread to a thin sheen, which makes it difficult to achieve a significant rate of recovery. Large quantities of containment boom and hundreds of vessels and skimmers are needed to concentrate thin, rapidly spreading oil slicks. The lack of approved disposal sites on land for contaminated water and waste, lack of port facilities to accept deep-draft vessels, and limited airlift capability to remote communities complicates the large-scale use of mechanical containment and recovery to respond to Arctic spills. Mechanical recovery can provide a viable option for small, contained spills in pack ice, or for larger spills under fast ice. Arctic-relevant mechanical recovery improvements include cold temperature operability and independent propulsion; however, response to a large offshore spill in the U.S. Arctic is unlikely to rely only upon mechanical containment and recovery because of its inefficiency.

Detection, Monitoring, and Modeling

To mount an effective response, it is critical to know where spilled oil is at any given time. Over the past decade, several large government and industry programs have evaluated the variety of rapidly developing remote sensing technologies used for detection, including sonar, synthetic aperture radar, infrared, and ground-penetrating radar. In addition, the use of unmanned aerial vehicles and autonomous underwater vehicles for oil detection and tracking has grown. However, there will always be a need for aerial observers to map oiled areas and transmit critical information to response crews. Detection methods work hand-in-hand with advanced oil spill trajectory modeling to understand where oil is moving. Promising advances in modeling have accounted for the incorporation of oil into brine channels as well as the bulk freezing of oil into ice, although better modeling of under-ice roughness is still needed. Investment in detection and response strategies for oil on, within, and trapped under ice will be necessary for contingency planning. In addition, robust operational meteorological-ocean-ice and oil spill trajectory forecasting models for the U.S. Arctic would further improve oil spill response efforts. Arctic oil spill research and development needs for improved decision support include: • Improving methods for in situ burning, dispersant application, and use of chemical herders; • Understanding limitations of mechanical recovery in both open water and ice; • Investing in under-ice oil detection and response strategies; • Integrating remote sensing and observational techniques for detecting and tracking ice and oil; • Determining and verifying biodegradation rates for hydrocarbons in offshore environments; • Evaluating the toxicity of dispersants and chemically dispersed oil on key Arctic marine species; and • Summarizing relevant ongoing and planned research worldwide to achieve synergy and avoid unnecessary duplication.

OPERATIONS, LOGISTICS, AND COORDINATION FOR AN ARCTIC OIL SPILL

Marine activities in U.S. Arctic waters are increasing without a commensurate increase in the logistics and infrastructure needed to conduct these activities safely.

As oil and gas, shipping, and tourism activities increase, the U.S. Coast Guard will need an enhanced presence and performance capacity in the Arctic. U.S. support for Arctic missions, including oil spill response, requires significant investment in infrastructure and capabilities.

Recommendation: As oil and gas, shipping, and tourism activities increase, the USCG will need an enhanced presence and performance capacity in the Arctic, including area-specific training, ice-breaking capability, improved availability of vessels for responding to oil spills or other emergency situations, and aircraft and helicopter support facilities for the open water season and eventually year round. Furthermore, Arctic assignments for trained and experienced personnel and tribal liaisons should be of longer duration, to take full advantage of their skills. Sustained funding will be needed to increase the USCG presence in the Arctic and to strengthen and expand its ongoing Arctic oil spill research programs. Vessel traffic is not actively managed in the Bering Strait or in the U.S. Arctic, nor is there a comprehensive system for real-time traffic monitoring. The lack of a U.S. vessel traffic monitoring system for the Arctic creates significant vulnerability for missions including oil spill response and creates undue reliance on private industry and foreign national systems. Private receivers are used to track vessels in the Bering Strait and along a large part of Alaskan coastal areas, but there are significant gaps in coverage. Consequently, there are numerous regional “blind spots” where an early indication of elevated risks may not be apparent to officials ashore. Recommendation: The USCG should expedite its evaluation of traffic through the Bering Strait to determine if vessel traffic monitoring systems, including an internationally recognized traffic separation scheme, are warranted. If so, this should be coordinated with Russia. The USCG should also consider obtaining broader satellite monitoring of Automatic Identification System signals in the Arctic through government means or from private providers.

Building U.S. capabilities to support oil spill response will require significant investment in physical infrastructure and human capabilities, from communications and personnel to transportation systems and traffic monitoring. Human and organizational infrastructure improvements are also required to improve international and tribal partnerships so as to leverage scientific and traditional knowledge and best practices. A truly capable end-to-end system for oil spill response would require integration of Arctic data in support of preparedness, response, and restoration and rehabilitation.

There is presently no funding mechanism to provide for development, deployment, and maintenance of temporary and permanent infrastructure.

For spills occurring within U.S. jurisdiction, the Oil Pollution Act of 1990 provides the necessary legal framework for the responsible party—often the owners or operators of energy or shipping companies—to fund response operations and provide compensation for damages. The burden of cost can fall on the government, however, when the cost of oil spill response exceeds liability limits or when the responsible party cannot be found. The Oil Spill Liability Trust Fund, a fund maintained by the federal government for these situations, may prove insufficient to cover the sociological and economic damages of affected communities. A “whole government” approach that includes the ability to deal with broad societal impacts of a spill may be necessary.

Local communities possess in-depth knowledge of ice conditions, ocean currents, and marine life in areas that could be affected by oil spills. Failure to include local knowledge during planning and response may increase the risk of missing significant environmental information, yet there appears to have been only modest efforts to integrate local knowledge into formal incident command-based responses. Developing and maintaining trained village response teams integrates local knowledge and utilizes existing human resources for effective oil spill response. The North Slope Borough has a well-developed local emergency response team, and the Northwest Arctic Borough is strengthening this capability in its region.

The potential impact of oil and countermeasures on wildlife is a major concern during an oil spill response. Controlling oil release and spread at the source of a spill, deterring animals from entering oiled areas, and capturing and rehabilitating oiled wildlife can help minimize the potential impact on wildlife, the broader ecosystem, and the food web. However, rehabilitation and release in the Arctic are complicated by remote locations, lack of response equipment, concerns over subsistence use of potentially oiled animals, and safety considerations when dealing with large animals such as polar bears and walruses. There is a general lack of scientific study, approved protocols, and consensus among decision makers regarding marine mammal deterrence. Wildlife response plans will need to include key indicators of environmental health, and prioritize response strategies. This includes a no-response strategy, which may be preferable for some species.

The Arctic acts as an integrating, regulating, and mediating component of the physical, atmospheric, and cryospheric systems that govern life on Earth. It is also undergoing rapid climate change, the rate of which is projected to accelerate in coming decades. Surface air temperature increases in the Arctic in recent decades are about two to four times larger than observed in the mid-latitudes, with evidence that the increase will continue. This “Arctic amplification” has been attributed to various complicated interactions between physical mechanisms (NRC, 2014), including albedo (solar reflectance) change due to sea ice and snowline retreat and latitudinal differences in surface energy radiation.

The most obvious evidence for Arctic change has been the well-documented retreat and thinning of Arctic sea ice cover. Between 1979 and 2013, the linear rate of decline of September ice extent was 13.7% per decade. The largest sea ice losses were documented in the Beaufort and Chukchi regions, particularly in the extremely low summer sea ice years of 2007 and 2012.  Recent increases in surface ocean temperatures in the Arctic, particularly in the Beaufort and Chukchi Seas, are related to this sea ice retreat. Mean surface ocean temperatures in the southern Beaufort Sea in August 2007 and 2012 were more than 2°C warmer than the August mean between 1982 and 2006.

Warming upper ocean temperatures may lead to increased thawing of offshore and coastal permafrost and coastal erosion, which is exacerbated by sea ice loss and increased sea state, as well as sea-level rise. Increased waves are already a feature of the Alaskan coastal zone. Other known climate change manifestations in the Arctic include changing atmospheric circulation patterns and increased cloud cover, related in part to the reduced sea ice extent .

The feedbacks and transitions occurring in this region will have significant implications for biodiversity, human benefits from the ecosystem, and other important processes within the Arctic and global system. As the Arctic changes, larger areas are becoming more accessible for shipping, exploration, and resource development, which come with increased concerns for oil spills and other types of potentially harmful incidents that could impact U.S. waters. There have been a number of recent efforts that highlight the importance of the Arctic to national interests .

These seas are home to ecosystems with a wide diversity of marine life. Many marine mammals and seabirds migrate seasonally to the Chukchi and Beaufort areas, with some permanent resident populations of polar bears and seals. Owing to the rapid warming of the Arctic and the associated decrease in sea ice, significant changes are occurring in the habitat, range, and behavior of the marine species that inhabit these waters.

The communities of the Beaufort and Chukchi Seas have limited infrastructure and no deepwater ports.

None of the communities have permanent road infrastructure connected to the main highway systems or large communities in Alaska, although some communities are seasonally connected by ice roads. Instead, the communities are largely dependent on air and seasonal marine transport for the movement of people, goods, and services outside their regions. All coastal communities receive barge shipments during the summer and early autumn open water months. Industrial activities of the region include commercial fishing in Kotzebue, Port Clarence, and Norton Sound; the Red Dog lead and zinc mine north of Kotzebue; and oil and gas fields on the North Slope.

There are an estimated 30 billion barrels of technically recoverable undiscovered oil in the U.S. Arctic, which equals approximately one-third of the total resource found in the entire circum-Arctic region. The subsurface Chukchi Sea Outer Continental Shelf (OCS) is estimated to contain 11 billion barrels of undiscovered economically recoverable oil and 38 trillion cubic feet of natural gas, while the subsurface Beaufort Sea OCS is estimated to contain 6 billion barrels of undiscovered economically recoverable oil and 11 trillion cubic feet of natural gas (at $110/barrel and $7.83/ thousand cubic feet of gas; BOEM, 2011). It is estimated that 80 to 90% of petroleum hydrocarbon entering the Arctic marine environment is from natural seeps (AMAP, 2008). Becker and Manen (1988) reported the presence of oil seeps in the coastal regions of Alaska and estimated submarine seepage to be approximately 1,000 tons/yr.

As crude oil seepage has been estimated to be 600,000 metric tons/yr globally, natural seeps may be among the most important sources of oil entering the ocean.

In the Chukchi Sea, most of the exploration activity occurs relatively far offshore (greater than 80-120 km), roughly equidistant from the villages of Point Lay and Wainwright. For this region, most of the resupply and support vessel traffic is between the offshore and points of origin of the exploration vessels (e.g., Dutch Harbor, and/or Nome). Crew change-out and some resupply also take place through Wainwright and Barrow. In the Beaufort Sea, oil exploration is primarily located between Kaktovik and Cape Halkett, especially near Camden Bay, the Colville River Delta, and Harrison Bay. Beaufort Sea exploration is closer to shore (~15-30 km), between Kaktovik and Nuiqsut. As with the Chukchi exploration effort, vessels arrive in the Beaufort Sea by traversing the Bering Strait and Chukchi Sea and rounding Point Barrow or, to a lesser degree, via Canadian waters to the east. Additional material resupply, crew change-out, and other vessel traffic are routed between the exploration areas and Prudhoe Bay.

Alaskan North Slope oil production infrastructure is located within a 120 × 40 km area between the Sagavanirktok and Colville Rivers along the central Beaufort Sea coastline. Pipelines extend approximately 30 km farther to the east, to BP’s Badami and ExxonMobil’s Point Thomson projects. Of the oil fields in this area, the Northstar, Oooguruk, and Nikaitchuq fields are produced from offshore facilities, with buried pipelines transmitting oil to facilities onshore. Other facilities are along the coast or in nearshore waters connected by a causeway (e.g., the Endicott Development, which was built on an artificial island). The location of these fields and pipelines influences the risk faced by communities and biological resources. Many villages are located along the coast, in large part because these areas are used by a variety of important subsistence species, especially marine mammals and birds.

Exploration drilling in the U.S. Beaufort and Chukchi Seas OCS began in the early 1980s, with 20 exploratory wells drilled between 1980 and 1989. The first discovery of oil in the Beaufort Sea OCS came in 1983 at the Tern (Liberty) field, and the largest discovery to date was made in 1993 at the Kuvlum field. Northstar was the first field to be developed in federal waters in the Beaufort Sea, beginning production in 2001. To date, 30 exploration wells have been drilled in the Beaufort Sea OCS; only three of those were drilled since the mid-1990s. In the Chukchi Sea OCS, five exploratory wells have been drilled. All were drilled between 1989 and 1991, and several discovered hydrocarbons.

Between 2008 and 2011, there were delays in additional exploration. In 2010, following the Deepwater Horizon oil spill, Secretary of the Interior Ken Salazar suspended proposed exploratory oil drilling in the Arctic.8 In 2011, the Bureau of Ocean Energy Management (BOEM) conditionally approved Shell’s 2012 Exploration Plans for both the Beaufort and Chukchi Seas, and the Bureau of Safety and Environmental Enforcement (BSEE) permitted Shell to begin drilling in 2012. Drilling was limited to two surface holes, due to issues with readiness of their dome containment device as well as the lack of a fully compliant spill response barge. Despite further hurdles, including the grounding of the Kulluk drilling unit, Shell continued to pursue drilling activity in early 2013, focusing their drilling activities at the Burger prospect in the Chukchi Sea and near the Kuvlum and Hammerhead fields in the Beaufort Sea. In February 2013, Shell announced that it was halting further exploration activities until 2014, at which point it planned to drill in the Chukchi Sea only. In its most recent announcement on January 30, 2014, Shell again postponed its drilling activities, citing as its reason a decision by the 9th U.S. Circuit Court of Appeals regarding a flawed environmental impact statement for lease sales in the Chukchi Sea.

Drilling operations in Arctic waters have been and continue to be highly controversial. The National Commission on the BP Deepwater Horizon Oil Spill (2011) noted that “the stakes for drilling in the U.S. Arctic are raised by the richness of its ecosystems.” Many individuals and conservation organizations advocate a halt to drilling in the region. Their concerns are primarily centered around inadequate baseline and monitoring data, especially for sensitive and important ecological areas; limited infrastructure available to address oil spills; challenges presented by little daylight in winter, rough weather, sea ice, and remoteness; and a lack of effective methods for responding to oil spills (Oceana, 2008; WWF, 2010; Pew Charitable Trust, 2013). Some of these concerns are based on experiences and environmental impacts from previous oil spills in the region, notably the Exxon Valdez accident.

Large commercial vessel traffic through the Bering Strait to Alaska’s northern regions has typically been dedicated to servicing the nearshore and onshore oil production facilities on the North Slope, transporting zinc and lead from the Red Dog mine through its port on the Chukchi Sea, and delivering fuel, equipment, and supplies to coastal communities. However, the vessel traffic situation in the region has recently changed noticeably. There has been an increase in seasonal maritime traffic from increased oil and gas exploration, ship-based oceanographic research missions from a variety of nations (including some that are newer to Arctic research, such as South Korea and China), tourism vessels, and shipping of oil and other commodities from Russia through the Northern Sea Route. These trends are expected to continue, with additional traffic potential from the development of large-scale mineral deposits in the Canadian and Russian Arctic and the development of new oil fields in the Alaskan OCS. More than 300 vessels transited the Bering Strait in 2012, up from approximately 260 in 2009, according to Automatic Identification System data. Of these, bulk carriers, tugs and barges, and research vessels constitute the largest categories.

Select Oil Spills and Maritime Accidents of Interest

Exxon Valdez — On March 24, 1989, Exxon Valdez, an oil tanker headed for Long Beach, California, struck a reef in Prince William Sound, Alaska. The collision with the reef punctured 8 of the tanker’s 11 cargo tanks. The damaged tanker spilled approximately 10.8 million gallons of North Slope crude oil. It was estimated to be carrying approximately 53 million gallons when it was wrecked. At the time, it was the largest single oil spill in U.S. coastal waters. Oil from the spill reached nearly 2,100 km of coastline, approximately 200 of which were considered heavily oiled. The other 1,750 km were either lightly or very lightly oiled. The Exxon Valdez Oil Spill Trustee Council estimates as many as 250,000 seabirds, 2,800 sea otters, 300 harbor seals, 250 bald eagles, and 22 killer whales died as a result of the incident.

Deepwater Horizon — On April 20, 2010, there was an explosion on the Deepwater Horizon (DWH) oil platform as it drilled the Macondo Well in the Gulf of Mexico. The uncontrolled oil flow from the wellhead led to a release of about 205 million gallons at a depth of ~1,500 m. The DWH oil spill is, to date, the largest offshore oil spill in U.S. history. Although a final Natural Resource Damage Assessment has not yet been released, preliminary status updates provide some insight into the damage caused by the spill. Approximately 1,750 km of coastline were oiled, 220 of which were heavily oiled. As of April 2012, field teams had collected 8,567 live and dead birds, of which 1,423 were rehabilitated and released. They collected 536 live sea turtles, of which 469 were later released, and 613 dead sea turtles. An Unusual Mortality Event for cetaceans in the northern Gulf of Mexico was declared prior to the spill, in February 2010, and is still in effect.

Kulluk — On December 27, 2012, the Kulluk, Shell’s conical drilling unit, was being towed from Dutch Harbor after drilling in the Beaufort Sea to Seattle for maintenance when its tow connection to the Aiviq separated. Although an emergency tow line was established between the Kulluk and both the Aiviq and the Nanuq, the Kulluk’s connections with both ships ultimately separated again on December 30. On December 31, the Kulluk grounded off of Sitkalidak Island, Alaska, due to strong winds and rough seas. On January 2, 2013, a salvage assessment team noted that the Kulluk had sustained some damage, but that it was stable and no sheen was visible. At the time that it grounded, the Kulluk was carrying approximately 139,000 gallons of ultra-low-sulfur diesel in addition to the 12,000 gallons of combined lube oil and hydraulic fluid needed for onboard equipment. Approximately 316 gallons of ultra-low-sulfur diesel fuel were released from the Kulluk’s lifeboats. On January 6, the Kulluk was refloated and moved to nearby Kiliuda Bay. Multiple salmon-bearing streams are located near the grounding site and Kiliuda Bay. Sitkalidak Island and Kiliuda Bay are within the area designated as critical habitat for Steller sea lion and southwest sea otter populations. These areas also provide habitat for waterfowl and shorebirds (including the Endangered Species Act-listed Steller’s eider), as well as harbor seals. Fin and humpback whales may also have been in Kiliuda Bay. However, no specific impacts to wildlife have been reported.

Selendang Ayu — On November 28, 2004, the Malaysian-registered bulk freighter Selendang Ayu departed Seattle, Washington, and began its trip to Xiamen, China. The vessel was loaded with soybeans and 1,000 metric tons of fuel. On December 6, in the Bering Sea, the vessel experienced engine failure. Despite attempts to fix the engine, it would not restart. Efforts over the next 2 days to tow the vessel were compromised and ultimately failed, due largely to weather. After drifting significantly, the Seledang Ayu ran aground near Unalaska Island, spilling 336,000 gallons of fuel and diesel fuel. Resources that were reportedly damaged from the spill include birds, fish, and vegetation. Following the incident, shoreline cleanup assessment teams identified nearly 115 km worth of shoreline segments that would require additional treatment. Some of the most heavily oiled areas were beaches located at the mouths of streams, which serve as habitat for anadromous fish. The carcasses of approximately 1,700 birds were either recovered or documented.

Environmental Conditions and Natural Resources in the U.S. Arctic

The components of the Arctic system interact with each other in a complex, evolving pattern. This chapter provides an overview of the physical and biological ocean processes and environments of the Bering Strait and the Chukchi and Beaufort Seas. This is important for understanding current conditions, but also for understanding trends, changes, and future data needs. This knowledge is essential to support safe operations in the Arctic marine environment; to guide oil spill prevention, response, and restoration; and to prioritize sampling and monitoring needs.

Of utmost importance to oil spill response is the rapid variability of the wind-forced surface ocean circulation. High-frequency radar systems in the Chukchi Sea, which map surface ocean currents, indicate complex flow patterns that can reverse direction in a matter of hours and can vary significantly in both magnitude (0-85 km/day) and direction over spatial scales of less than 10 km.

Ocean eddies are common in both the Chukchi Sea and the Beaufort Sea. Eddies centered at depths ranging from a few tens to hundreds of meters (with horizontal scales from a few kilometers to tens of kilometers) can trap and transport packets of water, or (in the case of a spill) entrained oil, over hundreds of kilometers. Satellite measurements reveal that the surface distribution of oil in the Deepwater Horizon spill was influenced by eddies in the Gulf of Mexico, which can extend to 800 m depth.

In addition to larger-scale eddies, there is complicated smaller-scale flow structure (characterized by horizontal scales around 1 km or less) in the ocean mixed layer beneath sea ice in the Beaufort Sea and in the mixed layer in ice-free conditions in the Chukchi Sea. This small-scale flow field, which is characterized by strong convergence and divergence zones, has been shown to have an important influence on tracer distribution patterns in mid-latitude, ice-free regions.

Ocean storm surges related to persistent high winds are an important factor for consideration in coastal spill response. Loss of Arctic sea ice has been shown to increase storm surge frequency. Extreme coastal flooding from water forced onshore by winds has been documented along the Canadian Beaufort Sea coast (see, e.g., Harper et al., 1988, who show maximum storm surge elevations of 2.5 m above mean sea level recorded at Tuktoyuktuk, Northwest Territories, Canada). These storm surges move ocean water into low-lying coastal environments, bringing salt and contaminants (in the event of a spill) that can have negative impacts on nearshore and terrestrial ecosystems.

MARINE WEATHER

There are a number of key weather parameters in the Beaufort and Chukchi region that can affect oil spill response, including air and water temperature, winds, low visibility, and hours of daylight. These conditions were highlighted as challenges to oil and gas operations and scientific research in the Arctic by the National Commission on the BP Deepwater Horizon Oil Spill (2011), among others.   Air temperatures are low through most of the year and exhibit little variability from year to year. Stegall and Zhang (2012) analyzed three-hourly North American Regional Reanalysis winds in an in-depth review of wind statistics in the Chukchi–Beaufort Seas and Alaska North Slope region for the period 1979-2009. They found a distinct seasonal cycle, with lowest wind speeds (~2-4 m/s) in May and largest (~9 m/s) in October, with extreme winds (up to 15 m/s) that are most often found in October. An increasing trend in the frequency and intensity of extreme wind events was identified over their study period; 95th percentile winds in October increased from 7 m/s in 1979 to 10.5 m/s in 2009. Wind fields over offshore areas are not always well-captured by coastal station data, which comprise the majority of source data for reanalysis winds. For example, along the North Slope, the significant influence of the Brooks Range in winter and the sea breeze effect from thermal gradients between land, ocean, and ice in summer can lead to stark differences between the coastal and offshore wind regimes. Wind measurements from Pelly Island in the Canadian Beaufort Sea, which may better represent the stronger and more variable Beaufort Sea marine winds than coastal stations to the west, recorded peak wind speeds of more than 20 m/s in most months in the period 1994-2008. Wind speed distribution can be used to assess how often a spill response technique such as in situ burning could be used. For example, a general upper wind limit for successful ignition and effective burning in booms or in situ burning is on the order of 10 m/s.

Limited daylight can be a major issue for oil spill response during freeze-up and over the winter. Off the Beaufort coast, the maximum of 21 hours of daylight during the breakup season in August reduces to an average of 11 hours in October.

From late November to January there is no daylight. Low-visibility conditions in the Beaufort Sea offshore occur most often during the breakup period in July and August.

The Beaufort Sea wave environment can present a significant challenge to oil spill response. Waves are predominantly generated during the open water season and generally propagate from the east and northeast, although recent analyses suggest sizeable waves now also come from the west . For much of the summer (July to August), the close proximity of sea ice is thought to prevent high sea states from forming. However, since 2001, upward-looking sonar measurements in the Beaufort Sea have shown a trend of large waves being present in summer and fall for longer durations, with significant interannual variability in wave heights. It has been hypothesized that because of larger fetches in summer, the summer wave field now contributes significantly to a marginal ice zone of broken-up floes along the Beaufort Sea ice edge. After the initial freeze-up in October, wave heights become limited.

Depending on the time of year, different sets of operating limits can cause interruptions to marine and air activities. From December to March, sea state is not an important factor. Operational downtime is dominated by darkness, snow, and low temperatures. Sea state and temperature are not critical factors from March to June or July; instead, downtime is related to wind and visibility such as fog and low clouds. From August to October, sea state is an important factor, while low air temperature and increasing darkness become critical from late October onward.

Sea ice is a critically important component of the Arctic marine environment, and understanding the ice environment is essential to anticipating the likely behavior of oil in, under, and on ice and determining applicable response strategies. At present, marine operations in the northern Chukchi and Beaufort Seas generally take place from late July to September, but future developments could lead to extended operating seasons or even year-round offshore oil production.

Even in the summer, ice can intrude on drilling locations and shipping routes. Furthermore, ice-free regions can transition to ice-covered conditions in a matter of days at the start of fall freeze-up.

Sea ice has a complicated seasonal evolution that is a function of seasonal temperature variations and mechanical forcing; its structure and evolution differ significantly from the coastal zone to offshore.

Land-fast ice refers to sea ice that is frozen along the shore, partially frozen to the seabed in shallow water (less than 2 m), and largely free-floating in deeper water (typically 15-30 m), where grounded ridges can act to anchor the sheet against drifting pack ice forces. Land-fast ice is most extensive along broad, shallow shelves. Although fast ice along the Beaufort Coast is generally stable near shore after December, severe storm events can cause winter shearing and movement and breakaway events, where large sections drift away from the fast ice edge in deeper water.  Beyond the bottom-grounded land-fast ice zone, floating fast ice extends seaward as the season progresses, until it reaches an outer limit within a shear zone; this zone of often significantly deformed ice can be highly variable in extent but typically occurs between the 15- and 25-m isobaths. The stable and relatively smooth nearshore areas of land-fast ice (out to approximately 12 m water depth) are used in the Beaufort Sea along the North Slope to construct winter ice roads that routinely carry heavy equipment in midwinter. Land-fast ice also serves as an important hunting and traveling platform for Arctic coastal communities.

Drift ice floats freely on the ocean surface without any stable connection to land.

Pack ice is drift ice whose concentrations exceed 6/10. The pack can open or close on the order of hours in response to winds and/or ocean currents. Typical midwinter pack ice drift rates in the Beaufort Sea are on the order of 5 km/day. Ice drift rates can exceed 50 km/day, based on 80th percentile exceedance values published by Melling et al. (2012) from moorings in the Canadian Beaufort Sea. Peak values measured in the same dataset over a 30-minute period reached 1.2 m/s. Even higher short-duration speeds (under 12 hours) are possible along the U.S. Beaufort Sea coast, where the mountain barrier effect of the Brooks Range amplifies offshore east-west winds. The net displacement of ice past a mid-shelf site north of Tuktoyaktuk between mid-October and mid-May was almost 2,000 km in 2007-2008. The actual distance along a drift path, including loops and backtracking, could be larger.

The distinction between fast ice and pack ice and the location of the ice edge at different times in the winter has important implications for oil fate and behavior. Ice features embedded in fast ice are generally static, so oil spilled into this stable ice regime is likely to remain very close to the discharge point (within hundreds of meters) for much of the year. In contrast, oil spilled into a pack ice environment north of the fast ice edge will drift with the ice over time.

Much of the ice cover encountered beyond the nearshore land-fast ice zone is deformed from crushing and shearing or from young ice rafting over itself in the first few months following freeze-up, forming ridges and ice rubble. These processes can create several-meters-thick patches of ice made up of multiple thin sheets. Ridges can extend well over 30 m below the surface and 5 m or more above the surrounding ice field. Monitoring ice thickness is a particularly serious technical question, as current satellite methods are deficient in this area; both CryoSat and ICES at satellite sea ice thickness data are subject to issues regarding validation.

Summer ice conditions are highly variable and largely dictated by wind patterns. In the Beaufort Sea, persistent easterly winds tend to move the pack away from shore, promoting extensive clearing along the coast, while westerly winds tend to keep the pack ice close to shore and limit the extent of summer clearing. In recent summers, ice drift in the Beaufort Sea has exhibited a stronger drift component toward the North Pole, moving ice away from the coast. Hutchings and Rigor (2012) found this to be an important factor leading to the low sea ice extent in summer 2007. The length of the melt season has increased by over 10 days per decade in the Chukchi and Beaufort Seas over the past 30 years. Over a 12-year period, the duration of summer open water in the central Chukchi Sea ranged from 8 to 24 weeks. The average duration of open water in the Chukchi has lengthened significantly on average over the past 30 years. There is also a clear gradation in open water duration with latitude following the retreat of the pack ice edge, from a historical average of 20 weeks or more off Cape Lisburne, to less than 4 weeks north of 72°N. While sea ice extent is at a minimum in the Chukchi-Beaufort region in the latter half of September, ice incursions lasting up to several weeks can occur when the remaining offshore pack ice is driven into shore by sustained westerlies or when remaining thick grounded remnants of the shear (Stamukhi) zone can float free in summer and drift through the region.

The fall transition from the first appearance of new ice to almost complete ice cover (8/10 or more) nearshore occurs rapidly in the Beaufort Sea, often within a week or less. Initial ice growth along the coast can reach 30 cm within two weeks after the first occurrence of new ice (Dickins et al., 2000). Farther offshore, freeze-up is characterized by the presence of substantial amounts of grease ice (thin layers of clumped crystals on the ocean surface that can resemble an oil slick) or slush before the first consolidated new ice sheet appears.

It is important to understand how the different ice regimes develop through the winter in the event that oil remaining from an accidental release remains trapped in the ice after freeze-up. In the winter, the Beaufort Sea pack ice moves in an episodic, meandering fashion with a typical net westerly drift in response to wind and currents. Mean monthly ice speeds reach a maximum in November and December (typically 9-13 km/day) and gradually decrease as the ice pack thickens and becomes more consolidated through January and February. Mean monthly speeds reach a minimum in March and April, with typical values of 3-5 km/day, although there are long periods (weeks or more) when the offshore ice moves very little or meanders locally at low speeds with no persistent sense of direction (Melling and Riedel, 2004). Average winter ice drift speeds in the Chukchi tend to be significantly greater than in the Beaufort and can exceed 40 km/day for 24 hours or more.

Sea ice dominates the Chukchi Sea from November to early July on average, 4 to 6 weeks shorter than in the Beaufort Sea. Fast ice begins to break up in early June, a month ahead of the Beaufort Sea.

By late June, the Chukchi Sea is often close to ice free, while the Beaufort Sea typically remains over 90% ice covered. Using satellite imagery from 1996-2004, Eicken et al. (2006) determined a mean date of June 4 as the onset of coastal ice breakup, with total clearing being attained on average by June 18, several weeks ahead of the Beaufort coast. Based on long-term ice chart interpretations, multiyear ice floes in high concentrations (5/10 or more) are rarely found south of Wainwright and very rarely south of Point Lay. Occasionally, old floes have been observed in low concentrations south of Cape Lisburne, but the southern Chukchi Sea is essentially free of old ice throughout the year. Clusters of generally low concentrations of old ice (2/10-3/10 on average) can occur for short periods of time off the northern Chukchi coast from Wainwright to Barrow. Invasions of significant multiyear ice into this coastal area occur approximately two to three times per decade.

Detailed mapping of coastlines, including geometry and elevation profiles, and knowledge of sediment size, shoreline stability, exposure to wave energy, and vegetation type are critical to understand potential effects of an offshore oil spill and post-oiling recovery of the coastline and associated habitats or protected environments—tundra, barrier islands, beaches and spits, lagoons, lakes, and deltas. The northern Alaskan coast consists of four main classifications (Hartwell, 1973). Land erosion coasts and wave erosion coasts together comprise approximately 30% of the coastline. Land erosion coasts have bedrock-based, high-relief sea cliffs, while wave erosion coasts have less relief, with cliffs that expose perennially frozen bedrock and ice-rich sediments. The remaining 70% of the coastline is classified as marine or river deposition coasts. Marine deposition coasts resemble wave erosion coasts, except sedimentation processes along the coast have built beaches, barrier islands, and spits. River deposition coasts, by contrast, are built by fluvial processes. About 45% of the coastline is classified as moderate relief (~2-5 m), comprised of cliffs and scarps of wave erosion and marine deposition coasts. Low-relief features (less than ~2 m), such as beaches, river deltas, barrier islands, and spits, make up about 25% of the coastline. High-relief cliffs (~5-8 m) are found along land erosion coasts and wave erosion coasts, while only a few sea cliffs have very high relief features (greater than ~8 m). Together, these comprise about 25% of the coast. The remainder of the coast is open water, such as river mouths and lakes.

Fresh water and sediment influx

The annual breakup of Arctic rivers can have great impact on nearshore bathymetry. The rivers draining into the Chukchi and Beaufort Seas are frozen up to nine months of the year, such that almost all of the yearly sediment and freshwater discharge is restricted to short periods in the spring and summer, slightly before and during the spring breakup. In the three-week annual breakup period, the Colville River (the largest river on the North Slope) delivers 43% of its annual discharge and 73% of its total suspended load to the ocean (Arnborg et al., 1967), leading to large areas of flooded land-fast ice. Ice chunks and river runoff erode nearshore bluffs and tundra, and eventual drainage of the floodwaters through cracks in the ice can create significant seabed erosion. In contrast during the winter, no significant freshwater discharge occurs from the Colville River, and seawater encroaches at least 50 km upstream in the delta (Arnborg et al., 1966).

The great seasonality of freshwater and suspended sediment influx could affect oil movement and entrainment in nearshore and offshore environments. Significant amounts of suspended sediments can be deposited on top of nearshore sea ice during flood events. In the case of an oil spill, these sediments could become contaminated and incorporated into the ice, and later redeposited as the ice breaks up and moves. The introduction of freshwater can also affect ocean currents through changes in stratification. Cross-shore salinity fronts established by river runoff can become unstable, causing energetic cross-shelf flows capable of carrying pollutants far offshore (Weingartner et al., 2009).

Permafrost and coastal stability

Like many Arctic coastlines, the North Slope is characterized by a continuous layer of permafrost below an active layer, the top soil layer that freezes and thaws over an annual cycle. Permafrost, a perennially frozen layer of ground material that remains at or below 0°C (32°F) for at least two years, often includes ground ice (e.g, ice lenses, layers, and wedges) that forms when water freezes along edges or cracks (UNEP, 2012). Degradation of this ice-bonded permafrost contributes to the high erosion rates observed along Arctic coastlines.

As measured in deep boreholes, permafrost temperatures may have increased by as much as 2°C to 4°C in the early to mid-20th century (Osterkamp, 2007), and by up to an additional 3°C in the 1980s and 1990s alone ( Jorgenson et al., 2010). Some studies report relatively stable permafrost temperatures at the turn of the century, but warming trends resumed after 2007 (Romanovsky et al., 2012). Record high warming was measured at most Alaskan permafrost observatories in 2011 and/ or 2012.

These warmer permafrost temperatures increase summer thaw and cause the melting of shallow ice wedges, which decreases the mechanical strength of the coastline sediment and causes the ground surface to subside and form depressions. The result is a lower coastal elevation and a terrain referred to as thermokarst. These changes, combined with increased wave energy related to increased areas of seasonally ice-free coastal water, elevated sea surface temperatures, and rising sea levels, have resulted in high rates of coastal erosion and greater inundation of low-lying coastal areas by seawater. Coastal bluffs along Arctic shorelines are exposed to wave energy that carves out niches at the base of frozen bluffs and eventually causes large blocks of the bluff to collapse.

The U.S. Beaufort shoreline is underlain with continuous permafrost that is estimated to extend out to at least the 20-m isobath; it has also been subject to some of the most dramatic erosion in the Arctic. The ice-rich bluffs have been severely impacted by the cycle of thermal and mechanical erosion described above. Between 1984 and 2011, measurements from Deadhorse, Alaska, at a depth of 20 m document a temperature increase of 2.5°C. Average erosion rates vary from site to site, with higher erosion rates being more typical along western stretches of the Beaufort Sea and lower rates being reported farther east. Jones et al. (2008) found that a mean erosion rate of 5.6 m/yr between 1955 and 2002, although certain sites had erosion rates as high as 25.9 m/yr. According to a study by Mars and Houseknecht (2007), there are data to suggest that the rate of coastal land loss doubled between 1955 and 2005. Jones et al. (2009b) reported similar findings and stated that in a 60-km stretch of coastline along the Beaufort Sea, the mean erosion rate increased from approximately 6.8 m/yr (1955-1979) to 13.6 m/yr (2002-2007).

NOAA’s Office of Coast Survey creates nautical charts for U.S. coastal waters. Arctic shoreline and hydrographic data are mostly obsolete, with limited tide, current, and water level data and very little ability to get accurate positioning and elevation. The nautical charts are of low quality; many were last updated in the 1950s and contain few soundings, little visual navigation, and small-scale, widely spaced surveys (NRC, 2011). Some were based on data last collected in the 1860s, such as the 1:700,000 chart for Kotzebue that was recently replaced by an April 2012 1:50,000 chart of Kotzebue Harbor (presentation by Doug Baird and Jeffrey Ferguson, NOAA, February 2013). There are also issues with tidal and current data (NRC, 2011). The need for more accurate charting in the Arctic was underscored by Presidential Executive Order 13547 ( July 19, 2010), which adopted the Final Recommendations of the Interagency Ocean Policy Task Force, including the need to address “environmental stewardship needs in the Arctic Ocean and adjacent coastal areas in the face of climate-induced and other environmental changes.” Improving navigation and geospatial infrastructure are also goals of NOAA’s Arctic Vision and Strategy (NOAA, 2011). In Canada, 2013-2014 priorities for Fisheries and Oceans Canada and other government departments include improving Canadian Hydrographic Services charting in the Canadian Arctic.5 As a first step, the Office of Coast Survey released an Arctic Nautical Charting Plan (NOAA, 2013).

Accurate bathymetric charts are part of the infrastructure required for effective oil spill response. The absence of modern charts represents a significant risk to navigation through uncharted obstructions. By extension, shortcomings in nautical charting increase the risk of a vessel-sourced oil spill. Poor charts could also complicate or impede other vessels’ abilities to respond to the accident or spill. If a spill was not entirely contained offshore, the ability of large vessels to come close to shore could be compromised. Given the necessity of marine transportation for oil spill response equipment, responders, vessels, and resources, charting infrastructure that provides for their safe and efficient transit is imperative. Poor charting could increase the cost of an oil spill response, as untrustworthy routes or transits require more comprehensive planning. Finally, poor nautical charts hinder preparedness, which could have negative impacts for oil spill response. Several recent reports have recommended that Arctic charting be prioritized (e.g., NRC, 2011).

OIL PROPERTIES

Crude oil is composed of a complex mixture of paraffinic, naphthenic, and aromatic hydrocarbons. Oils can differ from each other in a variety of ways, including density and sulfur content. The physical and chemical properties of an oil are not static but can vary between regions, within wells at the same location, and even within a given well over time (EPA, 2011). Key oil properties in cold water environments include measures of the American Petroleum Institute (API) gravity3 (an indicator of relative density in comparison to water), pour point (the temperature at which a fluid ceases to readily flow), and viscosity. As temperature decreases, viscosity increases and the possibility of going below the pour point becomes more likely. These properties are often considered in early stages of an oil spill response because they usually help define the most effective response options.

There are four standard groupings of oil types (ITOPF, 2013/2014). Group I oils, which include diesel fuel, are nonpersistent—they dissipate rapidly through evaporation and natural dispersion within a few hours and are unlikely to form emulsions, in which water droplets become entrained in the oil through mixing. Group II and III oils will partially dissipate, losing up to 40% of their volume through evaporation. These oils are likely to increase in volume because of their tendency to form viscous water-in-oil emulsions. This also leads to a lack of natural dispersion, especially in Group III oils. Group IV oils have low volatility and are highly viscous. They are highly persistent and are unlikely to evaporate or disperse (ITOPF, 2013/2014). The properties of a fresh oil may change with time, as the petroleum reservoir changes during production. Because of this, a given set of measurements to characterize a fresh oil represents a snapshot in time that may need to be updated. Nevertheless, the classification of oils into specific groups allows broad understanding of how they will behave under different environmental circumstances.

API gravity is measured in degrees, and is calculated using the following equation: API gravity = (141.5/SG) – 131.5, where SG is the specific gravity of the petroleum liquid at 60°F.

The development of biofuels has somewhat complicated this scheme, as they represent a class of materials that does not readily fit into the categories developed for petroleum products. While the viscosity and relative density of biofuels may be similar to crude oils and petroleum-based fuels, other properties may be quite different, especially as they relate to effectiveness of oil spill response methods. Ethanol from plant sources such as corn, sugar beets, or sugar cane is quite different from crude oil-based fuels because of its infinite solubility in water. In the event of a spill, ethanol would be more akin to a chemical spill rather than an oil spill. Another common form of biofuel is biodiesel, which may be made from either plant- or animal-based materials—animal fats such as tallow and lard; plant oils such as corn, canola, sunflower, and rapeseed; and recycled grease and used cooking oils.

Biodiesel generally has higher viscosity, flash point, and pour point compared to petroleum-derived diesel, with similar specific gravity (NREL, 2009). Unlike conventional diesel, biodiesel may be suitable for mechanical collection in the event of a spill because of its higher flash point and pour point, especially in colder environments. However, its response to dispersants may be quite different from that of crude oil-derived products because the biodiesel’s range of molecular components is narrower.

Many types of ships have recently been utilizing the Arctic marine environment, including government vessels and icebreakers, container ships, general cargo ships, bulk carriers, tanker ships, passenger ships, tugs and barges, fishing vessels, and vessels related to oil and gas exploration (Arctic Council, 2009). A record of transits through the Northern Sea Route in 201310 indicates that some tanker ships carried over 800,000 bbl of oil as cargo, although smaller ships carried as little as 35,000 bbl of diesel fuel cargo. These numbers illustrate the broad range in volume of potential spills from cargo ships, which does not include the fuel oil they carry aboard. In the U.S. Arctic, doubled-hulled barges that provide fuel resupply for Alaskan villages can carry over 6,000 bbl of oil cargo.

The villages store oil, diesel, and gasoline supplies for home and business heating, aviation fuel, and industrial needs for mining and oil and gas production. Because there are long periods between resupply due to sea and river ice, significant volumes of fuel may be stored in relatively close proximity to the shoreline. Examples include large storage facilities at the Red Dog Mine’s Delong Mountain Terminal and tank farms in the community of Barrow.

ARCTIC OIL SPILL COUNTERMEASURES

Arctic response strategies can leverage the natural behavior of oil in, on, and under ice. For instance, ice can bar the spread of oil, reducing spreading rates and leading to smaller contaminated areas; due to encapsulation or a lack of weathering, oil remains fresher for a longer time; and ice-covered areas generally have less severe wind and sea conditions. Despite the documented effects of climate change leading to later freeze-ups, greater extent of northerly ice edge retreat, and longer summer open water seasons, the Chukchi and Beaufort Sea coastlines are still buffered from oil spilled offshore by a fringe of fast ice for eight to nine months of the year. However, Arctic conditions impose many challenges for oil spill response—low temperatures and extended periods of darkness in the winter, oil that is encapsulated under ice or trapped in ridges and leads, oil spreading due to sea ice drift and surface currents, reduced effectiveness of conventional containment and recovery systems in measurable ice concentrations, and issues of life and safety of responders.

Several types of commercial activities are increasing in the Arctic, leading to the prospect of rapid growth in shipping along several routes. For example, use of the Northern Sea Route, and to a lesser extent the Northwest Passage, as a transportation route (Figure 4.1) is now more possible than ever before (IPCC, 2014). While some commercial shippers do not believe it will be economically viable for shipping in the near future (presentation by Gene Brooks, Maersk, February 2013), increased seasonal use by tankers and tug barges seems likely (Arctic Council, 2009). Taken along with other forms of vessel traffic, such as the tanker traffic from the Northern Sea Route, bulk carriers and tug-barge traffic transporting minerals and other bulk commodities, the inevitable increase in fishing fleets as fish stocks migrate northward, and even cruise ships that offer a glimpse of the Arctic for tourists, the Arctic has become a much busier place, with all of the associated risks that increased traffic involves. For the United States, the implications for traffic management, and by association, environmental protection, are very real. Keeping oil out of the water will not be purely a function of sound drilling practices, but of sound vessel traffic management, which raises a host of concerns for protection of Arctic ecosystems and for preparedness to respond in the event of a marine accident. It is also a concern for all Arctic nations, as an oil spill that occurs in one part of the Arctic may cross geographic boundaries and impact other nations’ waters, food supplies, livelihoods, and cultural resources.

Spills from these anticipated activities are likely to be relatively small and involve lighter oils (e.g., diesel, heating oil). Less likely but more consequential spills would be associated with offshore oil exploration and production, as well as from large bulk carriers operating from Kotzebue.

 

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