USGS studies coastal change along Alaska’s 66,000 miles of complex coastline - which stands as a tremendous resource to the Nation.
Coastal Change Mapping and Research in Alaska
This article is part of the October-November 2020 issue of the Sound Waves newsletter.
Alaska has the longest coastline in the Nation. Alaska’s 66,000 miles of Arctic and sub-Arctic shorelines and coastal ecosystems are geologically complex and diverse. They include glacial fjords, 52 active volcanoes, a delta that is 12 times larger than the Mississippi Delta, inlets, bays, parks, and refuges. These coasts have a long history as places of subsistence, indigenous culture, and economic opportunity for many Alaskans. They are also known for their hazardous weather and challenging ocean conditions and constitute a tremendous strategic, economic, and ecological resource to the Nation.
Accurate and contemporary mapping of Alaska’s coastal and nearshore regions is critical to informed use of these vast resources, to maritime domain awareness, to safeguarding the health and security of coastal communities, and to strengthening the Blue Economy.
In June 2020, the State of Alaska, the Alaska Ocean Observing System, and the Alaska Mapping Executive Committee, co-chaired by NOAA and the USGS, and including many other Federal agencies, published a report to support the November 2019 Presidential Memorandum that directed Federal agencies to develop a strategy to map the Alaskan coastline to advance our understanding of our oceans and coastlines and to promote efficient permitting related to ocean exploration activities. Read the strategy.
Additionally, a consortium of Federal agencies, the Alaska Ocean Observing System (AOOS), and the State of Alaska are participating on the Alaska Mapping Executive Committee’s (AMEC’s) Coastal Mapping Technical Subcommittee (CMTS) to develop an implementation plan for the Alaska coastal mapping order.
The CMTS includes representatives from Federal and State agencies that have responsibilities and jurisdictional authority in Alaskan coastal areas. The CMTS has met several times since July 2020 to review goals and objectives and to develop a strategy to guide and track Alaska coastal mapping efforts.
Here, we highlight three ongoing projects that fulfill part of our national strategy of advancing scientific understanding and providing information needed for managing and operating within Alaska’s diverse and remote coastal environments. These projects are also focused on bringing Alaska coastal mapping products and data into other ongoing nationwide efforts to ensure that comparable and consistent data and tools are available across the Nation. The USGS, BOEM, and NOAA are currently collaborating with the State of Alaska, the Universities of Alaska Anchorage (UAA) and Fairbanks (UAF), the AOOS, and Axiom Data Science to map and expand our understanding of coastal change processes and hazards along Alaska’s enormous remote shoreline.
National Assessment of Shoreline Change on the Coast of Alaska
Rates and patterns of historical shoreline change are quantified along Alaska’s coast as part of the USGS National Assessment of Shoreline Change and Alaska Coastal Processes and Hazards projects. Consistent methods used across the projects allows for systematic and objective comparisons of change along all U.S. coastlines. By understanding the causal relation between shoreline change and sediment movement with forcings, such as coastal storms and atmospheric conditions, the USGS can develop better models for understanding long-term vulnerability from coastal hazards and help coastal managers and communities plan for a changing climate. Objectives of this project include developing and improving coastal-change assessments, quantifying rates, and supporting long-term planning and decision making to ensure sustainable coastal economies, infrastructure, and ecosystems. Initial assessments are complete for the coast north of the Bering Strait to the United States-Canadian border. The next phase of analysis, started in FY20, extends the study area south to the Yukon-Kuskokwim Delta. Updated rates will be calculated as new shoreline datasets become available.
Alaska Coastal Processes and Hazards
The current warming trend across the Arctic and Alaska is bringing dramatic reductions in sea ice extent, permafrost thaw, and changing climatic and oceanographic patterns. Coastal impacts resulting from these changes are multidimensional and include rapid coastal erosion that threatens village and facility infrastructure, ecosystem stability, and critical cultural and social networks and needs. Parallel to the negative effects are new and emerging opportunities related to increasing accessibility and economic opportunities that also need to be addressed in planning and development strategies. The objectives of this project are to identify hazards, to quantify risk, and to evaluate effects of past, present, and future coastal processes on infrastructure, biology, and people along the Alaskan coast, including the Arctic. The methods integrate field studies and numerical modeling and include developing new methods for collecting spatially varying permafrost thermal exchange, nearshore bathymetry, and elevation data, and modeling tools for better characterizing future flood hazards, bluff recession, and barrier island morphodynamics.
Wave and Hydrodynamic Observations and Modeling in the Nearshore Beaufort Sea
Renewed interest in nearshore oil exploration and production in the central Beaufort Sea has created a general need to advance understanding of the dynamic physical conditions in this Beaufort Sea coastal region. Specifically, BOEM requires information on the effects that present-day and future sea-ice and atmospheric conditions will have on waves, currents, and sedimentation rates, and on ice pile-up events during the expected timeframe of the offshore Liberty Development Project (about 2020–50). Historical observational data were compiled, and a coordinated field effort was completed in 2019 to better characterize the system and support model calibration and validation. The USGS is developing a coupled wave-hydrodynamic-sediment transport model to produce a 40-year hindcast (1979–2019) and projection (2020–49) of waves, storm surge, and sediment transport potentials within Foggy Island Bay and the greater Stefansson Sound.
Learn more about how much value our oceans bring to different economies, from local communities to global markets. These include sectors related to seafood production, tourism and recreation, ocean exploration, marine transportation, and coastal resilience.