E icebergs from glacial ice. HMS Protector Blog 6
The extraordinary icebergs that we pass originate from glacial ice. These freshwater, large
masses of floating ice are calved from glacier tongues or from ice shelves derived from land ice. Berg ice is formed from compacted snow which can be up to hundreds of thousands of years old and is bluer in colour. The lexicon of names given to bergs is fascinating; tabular, blocky, wedged, domed, pinnacled, dry docked, bergy bit and growlers.
Older ice changes in colour from green to blue with age
Lookouts on the Bridge call out cautionary warnings to the Navigator using the appropriate description as each type will have a different characteristic shape underwater that may cause a hazard to the ship. Glacial and multiyear sea ice are as hard as concrete so the impact of a collision would risk structural damage to the ship.
The ship is fitted with an ice navigation radar which detects ice features through radar signals and converts it into a digital display. Giving the Bridge an azimuth view around the ship it allows the navigator to negotiate any larger ice features.
Image capture from ice navigation radar in the Antarctic Sound – if you are able to sequence the image capture stills into a short animation that would be great images courtesy of HMS Protector 
Lookouts on the Bridge call out cautionary warnings to the Navigator using the appropriate description as each type will have a different characteristic shape underwater that may cause a hazard to the ship. Glacial and multiyear sea ice are as hard as concrete so the impact of a collision would risk structural damage to the ship.
The ship is fitted with an ice navigation radar which detects ice features through radar signals and converts it into a digital display. Giving the Bridge an azimuth view around the ship it allows the navigator to negotiate any larger ice features.
However some icebergs may not be easily detected by radar due to their size or reflective surface, making it hazardous for the ship to navigate in fog or at night in the vicinity of iceberg Visual sighting is the only sure method, and lookouts are essential to avoid collision with a berg.
Emma Stibbon, ‘Mountains I’ Ink on paper
Emma Stibbon ‘Mountains II’ Ink on paper
I have to adapt my drawing methods to fast forward – as the ship is continuously moving forward the landscape slides by. I find using dilutions of black drawing ink allows me to respond more rapidly. Although my preferred medium is monochrome I sometimes have to switch to watercolour when the Polar colours can’t be ignored.
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