ICEBERGS!

What is an iceberg?

Icebergs are pieces of ice that formed on land and float in an ocean or lake. Icebergs come in all shapes and sizes, from ice-cube-sized chunks to ice islands the size of a small country. The term "iceberg" refers to chunks of ice larger than 5 meters (16 feet) across. Smaller icebergs, known as bergy bits and growlers, can be especially dangerous for ships because they are harder to spot. The North Atlantic and the cold waters surrounding Antarctica are home to most of the icebergs on Earth.

How do icebergs form, and where do they go?

Icebergs form when chunks of ice calve, or break off, from glaciers, ice shelves, or a larger iceberg. Icebergs travel with ocean currents, sometimes smashing up against the shore or getting caught in shallow waters.

When an iceberg reaches warm waters, the new climate attacks it from all sides. On the iceberg surface, warm air melts snow and ice into pools called melt ponds that can trickle through the iceberg and widen cracks. At the same time, warm water laps at the iceberg edges, melting the ice and causing chunks of ice to break off. On the underside, warmer waters melt the iceberg from the bottom up.

Why are icebergs important?

Icebergs pose a danger to ships traversing the North Atlantic and the waters around Antarctica. After the Titanic sank near Newfoundland in 1912, the United States and twelve other countries formed the International Ice Patrol to warn ships of icebergs in the North Atlantic.

The International Ice Patrol uses airplanes and radars to track icebergs that float into major shipping lanes. The U.S. National Ice Center uses satellite data to monitor icebergs near Antarctica. However, it only tracks icebergs larger than 500 square meters (5,400 square feet).

Why is 90% of an iceberg underwater?

Density also explains why most of an iceberg is found beneath the ocean's surface. Because the densities of ice and sea water are so close in value, the ice floats “low” in the water. ... This means that ice has nine-tenths, or 90 percent of water's density – and so 90 percent of the iceberg is below the water's surface.

Are icebergs dangerous?

Icebergs are dangerous because they are huge and they float low in the water which can cause danger to the ships. They tend to flip over at times. When they flip over the energy is so great it can cause tsunamis and on occasion can trigger earthquakes.

How old is an iceberg?

15,000 years

The glacial ice that icebergs are made of may be more that 15,000 years old. Seven-eighths of the iceberg's mass is below water. The average iceberg weight for the Grand Banks area is 100,000 to 200,000 tonnes and is about the size of a cubic 15-storey building.