An iceberg is a piece of
freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...
ice
Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaq ...
more than 15 m long
that has broken off a
glacier
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...
or an
ice shelf and is floating freely in open (salt) water. Smaller chunks of floating glacially-derived ice are called "growlers" or "bergy bits". The
sinking of the ''Titanic'' in 1912 led to the formation of the
International Ice Patrol
The International Ice Patrol is an organization with the purpose of monitoring the presence of icebergs in the Atlantic and Arctic Oceans and reporting their movements for safety purposes. It is operated by United States Coast Guard but is fund ...
in 1914. Much of an iceberg is below the surface, which led to the expression "
tip of the iceberg" to illustrate a small part of a larger unseen issue. Icebergs are considered a
serious maritime hazard.
Icebergs vary considerably in size and shape. Icebergs that
calve from glaciers in
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...
are often irregularly shaped while
Antarctic
The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other ...
ice shelves often produce large tabular (table top) icebergs. The largest iceberg in recent history (2000), named
B-15, measured nearly 300 km × 40 km.
The largest iceberg on record was an Antarctic tabular iceberg of over [] sighted west of Scott Island, in the South Pacific Ocean, by the USS Glacier (AGB-4), USS ''Glacier'' on November 12, 1956. This iceberg was larger than Belgium. Big icebergs are also often compared in size to the area of
Manhattan
Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is also coextensive with New York County, one of the original counties of the U.S. state ...
.
Etymology
The word ''iceberg'' is a partial
loan translation
In linguistics, a calque () or loan translation is a word or phrase borrowed from another language by literal word-for-word or root-for-root translation. When used as a verb, "to calque" means to borrow a word or phrase from another language wh ...
from the
Dutch word
''ijsberg'', literally meaning '' ice mountain'', cognate to
Danish
Danish may refer to:
* Something of, from, or related to the country of Denmark
People
* A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark
* Culture of Denmark
* Danish people or Danes, people with a Danish ance ...
''isbjerg'',
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
''Eisberg'',
Low Saxon
Low Saxon, also known as West Low German ( nds, Nedersassisch, Nedersaksies; nl, Nedersaksisch) are a group of Low German dialects spoken in parts of the Netherlands, northwestern Germany and southern Denmark (in North Schleswig by parts of th ...
''
Iesbarg'' and
Swedish
Swedish or ' may refer to:
Anything from or related to Sweden, a country in Northern Europe. Or, specifically:
* Swedish language, a North Germanic language spoken primarily in Sweden and Finland
** Swedish alphabet, the official alphabet used by ...
''
isberg''.
Overview
Typically about one-tenth of the volume of an iceberg is above water, which follows from
Archimedes's Principle of buoyancy; the
density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...
of pure ice is about 920
kg/m3 (57 lb/cu ft), and that of
seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appro ...
about . The contour of the underwater portion can be difficult to judge by looking at the portion above the surface.
The largest icebergs recorded have been