UNH-NOAA Ocean Mapping Expedition Yields New Insights into Arctic Depths
By Beth Potier, Media Relations
February 13, 2008
International Bathymetric Chart of the Arctic Ocean. Chukchi Borderland is
between 160W and 170W degrees longitude and 75N and 80N degrees latitude. Credit:
New Arctic sea floor data released today by UNH and the National Oceanic and
Atmospheric Administration suggests that the foot of the continental slope
off Alaska is more than 100 nautical miles farther from the U.S. coast than
The data, gathered during a recent mapping expedition to the Chukchi Cap some
600 nautical miles north of Alaska, could support U.S. rights to natural resources
of the sea floor beyond 200 nautical miles from the coast.
“We found evidence that the foot of the slope was much farther out than
we thought,” said Larry Mayer, expedition chief scientist and co-director
of the Joint Hydrographic Center at UNH. “That was the big discovery.”
Coastal nations have sovereign rights over the natural resources of their
continental shelf, generally recognized to extend 200 nautical miles out from
the coast. The Law of the Sea Convention, now under consideration in the U.S.
Senate, provides nations an internationally recognized basis to extend their
sea floor resource rights beyond the foot of the continental slope if they
meet certain geological criteria backed up by scientific data.
The Bush administration supports approval of the convention.
The Arctic mapping expedition, conducted between Aug. 17 and Sept. 15, 2007
aboard the U.S. Coast Guard Cutter Healy, employed sophisticated echo sounders
to survey this relatively unexplored region, providing much finer-grained data
and images than existed previously. The data are available at http://www.ccom.unh.edu.
“We now have a better geologic picture of what’s happening in
that area of the Arctic,” said NOAA Office of Coast Survey researcher
Andy Armstrong, co-chief scientist on the expedition and NOAA co-director of
the Joint Hydrographic Center. “These are valuable data for NOAA and
the United States, and I’m pleased that we’re making them available
for anyone to use.”
Mapping more than 5,400 linear nautical miles, the research team also found
scours on the Chukchi Cap some 1,300 feet below the surface, likely caused
by the scraping of an ice sheet on the sea floor, and deep pockmarks of unknown
origin at a depth of 1,600 feet.
“The sea floor is full of mysteries, and beneath the Arctic ice cap
those mysteries are even harder to reveal,” said Mayer. “The kind
of full-coverage, high-resolution mapping we do provides critical insight for
meeting the criteria of the Law of the Sea Convention as well as the geologic
history of the region.”
Prior to this work, the only seafloor mapping data available in the ice-covered
Arctic came mostly from ice islands and helicopters. These sparse individual
measurements produced low-resolution maps compared to the Joint Hydrographic
Other mapping expeditions led by the Joint Hydrographic Center, a NOAA-UNH
partnership, have explored the Bering Sea (2003), the Atlantic coast of the
U.S. (2004 and 2005), the Gulf of Alaska (2005), Mariana Islands (2006 and
2007), and the Gulf of Mexico (2007).
“Understanding the bathymetry and geological history of the Arctic is
an important part of understanding global climate change,” said Mayer. “The
Arctic acts as a global spigot in controlling the flow of deep ocean currents
that distribute the Earth’s heat and control climate. The Arctic is the
canary in the coal mine.”
NOAA is dedicated to enhancing economic security and national safety through
the prediction and research of weather and climate-related events and information
service delivery for transportation, and by providing environmental stewardship
of our nation's coastal and marine resources. Through the emerging Global Earth
Observation System of Systems (GEOSS), NOAA is working with its federal partners,
more than 70 countries and the European Commission to develop a global monitoring
network that is as integrated as the planet it observes, predicts and protects.
On the Web:
Joint Hydrographic Center at UNH: http://www.ccom-jhc.unh.edu