Wow!
Amazing Striped Icebergs &
Other Interesting Formations
Icebergs: General Information
• An iceberg is a large piece of ice from
freshwater that has broken off from a snowformed glacier or ice shelf and is floating in
open water. It may subsequently become
frozen into pack ice. Alternatively, it may
come to rest on the seabed in shallower
water, causing ice scour (also known as ice
gouging) or becoming an ice island.
Icebergs Cont.
• Because the density of pure ice is about 920
kg/m³, and that of sea water about 1025
kg/m³, typically only one-tenth of the volume
of an iceberg is above water. The shape of
the underwater portion can be difficult to
judge by looking at the portion above the
surface. This has led to the expression "tip of
the iceberg", for a problem or difficulty that
is only a small manifestation of a larger
problem.
Most of the iceberg is under water.
How Big is Big
• Though usually confined by winds and
currents to move close to the coast, the
largest icebergs recorded have been calved,
or broken off, from the Ross Ice Shelf of
Antarctica. Iceberg B-15, photographed by
satellite in 2000, measured 295 km long and
37 km wide (183-23 mi), with a surface area
of 11,000 km² (4,250 mi²). The mass was
estimated around three billion tons.
• Rhode Island:
– Area 1,545 sq. mi.
– Length: 48 miles
– Width: 37 miles
• B-15:
– Surface area 4,250
sq. mi.
– Length: 183 miles
– Width: 23 miles
• Comparison:
– B-15 was almost
three times the size
(surface area) of
Rhode Island.
B-15 Comparison
Amazing Striped Icebergs
• the photographs were taken by Norwegian
sailor Oyvind Tangen from aboard a research
vessel. The iceberg photographs were snapped
in an area several hundred miles north of the
Antarctic. As the message explains, blue stripes
are formed as iceberg layers melt and refreeze
quickly, while green stripes are created by the
freezing of algae-rich sea water. Other colored
stripes, such as black, brown and yellow, were
created by sediment collected by the ice as it
moved down a hillside towards the sea. The
icebergs may have taken hundreds or even
thousands of years to form.
Other Interesting Glacial Features
• Sometimes referred to as “ice wave” pictures,
the pictures that follow show ice formations
created by glaciation, melting and refreezing,
and other natural forces, over very long
periods of time. The "ice wave" photographs
are not related to the striped iceberg images
and were taken at a different time and place
by a different photographer, scientist Tony
Travouillon.