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Frequently Asked Questions
| Q. |
How does the National
/ Naval Ice Center (NIC) determine how much ice is
in the polar regions? |
| A. |
The remoteness of the
Polar Regions limits the amount of direct observation
of sea ice. Hence, more than 95% of the data used in
sea ice analyses are derived from the remote sensors
on polar-orbiting satellites. Sea ice analyses and forecasts
are primarily prepared using satellite imagery and ice
reconnaissance. |
| Q. |
What
areas does NIC cover? |
| A. |
NIC provides worldwide
operational sea ice analyses and forecasts. NIC produces
these analyses and forecasts of Arctic, Antarctic, Great
Lakes, and Chesapeake Bay ice conditions to support customers
with global, regional, and tactical scale interests. |
| Q. |
How
small can an iceberg be? |
| A. |
To be classified
as an iceberg, the ice must originate from glaciers
or shelf ice. The height must be greater than 5 meters
above sea-level, the thickness must be 30-50 meters,
and the area must cover at least 500 square meters.
There are smaller pieces of ice known as bergy bits
and growlers. Bergy bits and growlers can originate
from glaciers or shelf ice, and may also be the result
of a large iceberg that has broken up. A bergy bit
is classified as a medium to large fragment of ice.
Its height is generally greater than 1 meter but less
than 5 meters above sea-level and its area is normally
about 100-300 square meters. Growlers are smaller fragments
of ice and are roughly the size of a truck or grand
piano. They are often transparent but can appear green
or black in color. They extend less than 1 meter above
the sea surface and occupy an area of about 20 square
meters. |
| Q. |
When
was National Ice Center established? |
| A. |
The National Ice Center
was established in 1995, when the U.S. Coast Guard joined
the Navy/National Oceanic and Atmospheric Administration
(NOAA) Joint Ice Center. |
| Q. |
Why are you called
the National Ice Center / Naval Ice Center? |
| A. |
The
National Ice Center was established as an interagency
comprised of three components: the Naval Ice Center,
NOAA, and the U.S. Coast Guard.
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| Q. |
What is the egg
code?
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| A. |
The World Meteorology
Organization (WMO) system for sea ice symbology is frequently
referred to as the "Egg Code" due to the oval
shape of the symbol. |
| Q. |
How do you interpret
the egg code on the charts? |
| A. |
The egg
code on the ice charts
defines the concentration, stage of development, and
forms of ice. Refer to the following
links for more information: Egg
Code and SIGRID. |
| Q. |
How often is
the iceberg database updated? |
| A. |
The iceberg database,
which includes icebergs only in the southern hemisphere,
is updated weekly. The NIC is the only organization that
names and tracks all Antarctic
Icebergs. |
| Q. |
Does NIC do any
research on Global Warming? |
| A. |
No, the primary mission
of the NIC is to provide strategic, tactical, and operational
ice products and services to meet requirements of U.S.
national interests and U. S. government agencies. Our
products, available on the World Wide Web, are used by
outside organizations to derive or interpret information
of scientific value. |
| Q. |
What is the
International
Ice Patrol and why was it formed? |
| A. |
The mission of the
International Ice Patrol is to monitor iceberg dangers
near the Grand Banks of Newfoundland and provide the
limits of all known ice to the maritime community. While
icebergs are a constant navigational hazard in the Arctic,
the cold Labrador Current carries some of them south
to the vicinity of the Grand Banks and into the great
circle shipping lanes between Europe and the major ports
of the United States and Canada. Vessels transiting this
area try to make their voyage as short and as economical
as possible. Therefore, ships in the vicinity of the "limits
of all known ice" normally will pass just to the
south of this boundary. Vessels passing through the Ice
Patrol’s published ice limit run the risk of a
collision with an iceberg. In this area, the Labrador
Current meets the warm Gulf Stream and the temperature
differences between the two water masses can reach up
to 20 degrees Celsius, which may result in dense fog.
The combination of icebergs, fog, severe storms, fishing
vessels, and busy Trans-Atlantic shipping lanes makes
this area one of the most dangerous to navigate through.
This fact was grimly brought to light with the sinking
of the R.M.S. TITANIC in 1912, after it struck an iceberg
and approximately 1,517 passengers and crew perished.
Sources: International Ice Patrol - http://www.uscg.mil/lantarea/iip/ |
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