Frequently Asked Questions

Frequently-Asked Questions about the Extended Continental Shelf on the U.S. Department of State Web site

Frequently-Asked Questions about the 2009 U.S.-Canada Arctic Continental Shelf Survey

Where are you going on this mission, and how much will you map?

This year's mission is picking up where the team's 2008 cruise left off. This year, data collection will emphasize the region of the central to northern Chukchi Borderland northwards onto Alpha-Mendeleev Ridge and eastwards toward the Canada Archipelago. Final locations will depend on ice conditions.

What are the dates for the 2009 cruise for the US Coast Guard Cutter Healy and the Canadian Coast Guard Ship Louis S. St-Laurent?

The Healy leaves port in Barrow, Alaska on Friday, August 7 and is due to return on Wednesday, September 16. The Louis S. St-Laurent departs Kugluktuk, Nunavut on Friday, August 7 and returns on Wednesday, September 16. The two vessels are scheduled to meet on Sunday, August 9 and stay together until Saturday, September 12.

Why are the U.S. and Canada working together to collect data on the extended continental shelf?

Both countries have an interest in defining the extent of the Arctic continental shelf. Working together saves millions of dollars for both nations, provides data both nations need, ensures that data are collected only once in the same area, and increases scientific and diplomatic cooperation. The 2009 mission is the second year the U.S. and Canada have collaborated in extended continental shelf data collection in the Arctic, and another year of the partnership is planned.

What are the roles of the U.S. Coast Guard Cutter Healy and the Canadian Coast Guard Ship Louis S. St-Laurent on this mission?

As in the cruise last summer, the U.S. Coast Guard Cutter Healy will collect bathymetric data and the Canadian Coast Guard Ship Louis S. St-Laurent will collect seismic data. In heavy ice conditions in certain portions of the Arctic, a two-ship operation is necessary to collect data. Healy will clear a path for the Louis S. St-Laurent's seismic data collection work. In ice conditions that preclude operation of the seismic systems aboard Louis S. St-Laurent, she will break ice in advance of Healy to improve the quality of the bathymetric data. Both the U.S. and Canada will use the data the ships collect.

What are the respective roles of the agencies involved in this mission?

  • The U.S. Coast Guard (USCG) operates and crews the U.S. Coast Guard Cutter Healy.
  • The U.S. Department of State (DoS) handles diplomatic and legal aspects of this year's mission and the U.S. ECS Project in general.
  • The University of New Hampshire's (UNH) Dr. Larry Mayer will be the Chief Scientist aboard the Healy. Dr. Mayer is also Co-Director of the Center for Coastal Ocean Mapping/Joint Hydrographic Center, a partnership between NOAA and UNH.
  • The National Oceanic and Atmospheric Administration (NOAA) has the lead in collecting bathymetric data, which it is doing in conjunction with the Center for Coastal Ocean Mapping/Joint Hydrographic Center, a partnership between NOAA and UNH.
  • The U.S. Geological Survey has the lead in collecting seismic data for the U.S ECS Project, and Dr. Deborah Hutchinson of USGS will be aboard the Canadian Coast Guard Ship Louis S. St-Laurent, which will be collecting seismic data during the mission.
  • The Geological Survey of Canada (Natural Resources Canada) and the Canadian Hydrographic Service (Department of Fisheries and Oceans) are tasked with Canada's extended continental shelf data collection. Dr. David Mosher of the Geological Survey of Canada will be the Canadian chief scientist.
  • The Canadian Hydrographic Service (Department of Fisheries and Oceans) has responsibility for collection of bathymetric data. Dr. John Biggar of the Canadian Hydrographic Service is the Hydrographer in Charge.
  • Canada's Department of Foreign Affairs and International Trade (DFAIT) will prepare and present Canada's submission to the Commission on the Limits of the Continental Shelf.

What tools will be used on this year's mission?

The U.S Coast Guard Cutter Healy uses a Seabeam 2112 multibeam echosounder, a sophisticated instrument mounted on the hull of the icebreaker that measures a wide swath of bathymetry, or seafloor depths, as the ship travels. Every few seconds, the multibeam echosounder collects up to 121 individual depth measurements over a swath 2.5 to 3 times the water depth. The water depth in the 2009 mission varies from about 1,000 meters on the Chukchi Borderland to about 3,800 meters in the Canada Basin. Generally, water depths will be no shallower than 2,500 meters.

The three-dimensional maps that are created from the multibeam data reveal details and features of the seafloor that other echosounders could not collect. The Healy will also collect gravity data, useful for determining the nature of the subsurface, and sub-bottom profiler data, useful in providing information on the nature of sediments.

The Canadian Coast Guard Ship Louis S. St-Laurent will collect seismic data, which provides information on the depth, thickness, geometry, and other characteristics of the sediments lying at and below the seafloor. To collect seismic data, a sound source is towed behind the ship and emits acoustic energy at constant time or distance intervals. Transmitted energy is reflected or refracted from boundaries between geologic layers many kilometers deep, and detected by digital sensors towed behind Louis S. St-Laurent. The signals are processed and displayed during the cruise to monitor data quality. Additional processing, analysis, mapping, interpretation, and display are done post-cruise to maximize data quality and derived information.

Is the data from this year's mission public?

The bathymetric and sub-bottom data collected thus far by the United States in U.S. and international waters in support of defining its continental shelf has been released to the public and can be downloaded from the National Geophysical Data Center Web site and from the Web site for the Center for Coastal and Ocean Mapping/Joint Hydrography Center at the University of New Hampshire. All seismic reflection data collected by the Canadians and all bathymetric and sub-bottom data collected by either party within the Canadian Exclusive Economic Zone (EEZ) will be held proprietary for a period of years. These same data release policies will pertain to the 2009 data.

Is the data being collected this year useful for other purposes?Definitely. Several significant discoveries have resulted from the bathymetric data collected thus far, while also providing direction to other research. In the Arctic, the newly discovered bathymetric "pockmarks" on the Chukchi Borderland are likely gas seeps that could host chemosynthetic ecosystems, and additional exploration is planned there. Recently revealed glacial scours in the Arctic are changing our understanding of the nature of ice sheet behavior and thus global climate variability. The discovery of an unmapped seamount, since named Healy Seamount, will enable safer submarine navigation. Also, new bathymetry has helped the Navy and others gain a better understanding of Arctic gravity data.

Bathymetric data collection in the Gulf of Alaska has produced maps that have changed and enriched scientists' ideas about the tectonic origin of the margin and have revealed previously unknown details about sedimentary processes, such as the build-up of deep-sea fans and the channels that crisscross the margin, some of them running almost to Hawaii. These data have also revealed a chain of buried seamounts in the Gulf of Alaska.

Bathymetric data collection as part of ECS delineation in the Atlantic provided the biological science community data necessary for planning submersible dives to the unique ecosystems associated with the New England seamounts.

Additional knowledge of the morphology, structure and composition of the margin sediment will provide insight into the history of climatic change and environmental variability. Increased understanding of continental margin history and processes will improve assessment of threats (earthquakes, submarine landslides, tsunamis) to marine operations and coastal communities; bathymetric data, in particular, are critical for tsunami modeling.