An iceberg is the term for a massive piece of ice of greatly varying shape, protruding more than 5 metres above sea-level, which has broken away from a glacier, and which may be afloat or aground.
There are many types of icebergs, and they can be described as tabular, dome-shaped, sloping, pinnacled, dry-docked, blocky, weathered or glacier bergs in addition to having a size qualifier.
Besides a variety of shapes and sizes, icebergs sometimes appear with unusual colouring.
An irregularly shaped iceberg.
A flat-topped iceberg. Most tabular bergs form by calving from an ice shelf and show horizontal banding.
An iceberg which is smooth and rounded on top.
An iceberg which is rather flat on top and with steep vertical sides on one end, sloping to lesser sides on the other end.
An iceberg with a central spire or pyramid, with one or more spires.
An iceberg which is eroded such that a U-shaped slot is formed near or at water level, with twin columns or pinnacles. This is also referred to as a twinned iceberg.
A flat-topped iceberg with steep vertical sides.
An iceberg that shows marked signs of deterioration from the effects of atmosphere and ocean.
A large piece of floating ice protruding about 5 m above sea-level, which has broken away from an Arctic ice shelf, having a thickness of 30–50 m and an area of from a few thousand square metres to 500 km² or more, and usually characterised by a regularly undulating surface which gives it a ribbed appearance from the air.