Glossary of British Sea Ice Terms Matthew Ayre & Dinah malloy Thompson © 2014 Definition Date 1821 1845 1901 1919 1930 1936 1950 1963 1969 1977 1995 William Scoresby: An Elisha Kent Kane: George Murray FRS: J.M. Wordie: South Marine Observers Marine Observers Marine Observers Marine Observers Marine Observers Marine Observers Marine Observers Account of the Arctic Arctic Exploration in The Antarctic Manual Handbook: 5th Edition Handbook: 6th Edition Handbook: 7th Edition Handbook: 8th Edition Handbook: 9th Edition Handbook: 10th Handbook: 11th Regions and a the years 1853, '54 Edition Edition Reference Description of the and '55. Northern Whale Fishery A sheet of ice so An extensive surface A sheet of ice of such A sheet of ice of such An area of pack ice of An area of pack ice of A area of pack ice Area of pack ice/drift Area of pack ice Area of pack ice Area of floating ice extensive, that its of floating ice. extent that its extent that its limits such extent that its such extent that its consisting of very ice, consisting of any consisting of any size consisting of any size consisting of any size limits cannot be termination cannot be cannot be seen from limits cannot be seen limits cannot be seen large floes several size of floes, of such of floes, which is of floes, which is of floes, which is discerned from a seen from the crows the masthead from a ships mast from a ships mast miles across, of such an extent that its greater than 10km (6 greater than 5.4 n. greater than 10 cm ship's mast head. nest. head head extent its limits cannot limits cannot be seen miles) across. May be mile across (cf. ice across (cf. patch). be seen from the from the crows nest. designated as: Large- patch). See Large, Field mast head. over 20km (12 miles) Medium, Small ice- across, Medium - 15- field. 20km (9-12miles) across, Small - 10- 15km (6-9 miles) across. Similar to a Field, but A detachted portion of The same as a field, An area of ice, level An area of ice other An area of ice other A piece of sea ice A single piece of sea Any relatively flat Any relatively flat Any relatively flat smaller; in as much a field. except its limits can or hummocked, than fast ice whose than fast ice whose other than fast ice, ice, other than fast piece of sea ice 20m piece of sea ice 20 m piece of sea ice 20 m as its extent can be be made out from the whose limits are limits are within sight. limits are within sight. large or small. Light ice, large or small, (66ft) or more across. or more across. Floes or more across. Floes seen. This term, crows nest. within sight. Includes floes are anything up described if possible Floes are subdivided are sub- divided are subdivided however, is seldom all sizes between to 2-3ft in thickness; as Light or Heavy according to according to according to applied to pieces of brash on the one floes of greater according to horizontal extent as horizontal extent as horizontal extent as ice of less diameter hand and fields on the thickness, both level thickness. Vast: over follows: Giant: over follows : GIANT: Over follows: GIANT: Over than half a mile or a other. Light floes are and hummocked, are 10km (5.5miles) 10km (6miles) across, 5.4 n. mile across. 10 km across. VAST: mile between 1 and 2 feet called Heavy Floes. across, Big : 1-10km Vast: 2-10km (1- VAST: 1.5 -5.4 n. mile 2-10 km across. B1G: in thickness (anything (0.5 - 5.5miles) 6miles) across, Big: across. BIG: 500- 500-2000 m across. Floe thinner being young across, Medium : 200- 500-2000m (1/4 to 2000 m across. MEDIUM: 100-500 m ice). Those exceeding 1000m (660ft- 1mile) across, MEDIUM: 100-500 m across. SMALL: 20- 2 feet in thickness are 0.5miles) across, Medium: 100-500m across. SMALL: 20- 100m across. generally termed Small : 10-200m (33- (330ft to 1/4mile) 100 m across. heavy floes, being 660ft) across. across, Small: 20- generally 100m (66-330ft) hummocked, and in across. the Antarctic, at any rate, coverd by fairly deep snow. Consists of pieces Detached Ice in Pieces smaller than a Loose open ice, Loose very open pack Loose very open pack Loose, very open Term used in a wide Term used in a wide less than Floes, of motion. floe. where the area of where water where water pack, where water sense to include any sense to include any various shapes and water exceeds that of predominates over ice predominates over ice predominates over area of sea ice, other area of sea ice, other magnitudes ice. Generally drift ice ice. Vessels can than fast ice, no than fast ice, no is within reach of the usually proceed at full matter what form it matter what form it swell, and is a stage or moderate speed takes or how takes or how it is in the breaking down with little alteration of disposed. disposed. When of pack ice, the size course. The floes are concentrations are of the floes being in most cases smaller high, i.e. 7/10 or much smaller than the or lighter than those in more, drift ice may be Drift Ice latter (Scoresby's use close or open pack, replaced by the term of the term drift ice for and often associated pack ice. pieces of ice with rotten ice and intermediate in size brash. A term between floes and formerly much in use, brash has, however, but liable to confusion quite died out). The with 'drivis', the Antarctic and Arctic Norwegian equivalent Pack ice usually has a of pack ice girdle or fringe of Drift ice. Smaller still than Drift Ice broken up into Small fragments and Small fragments and Small fragments and Small fragments and Small fragments, not Accumulation of small Accumulations of Accumulations of Accumulations of ice, consisting of small pieces. nodules, the wreck of roundish nodules; the rounded nodules, the rounded nodules, the more than 6 feet fragments not more Floating ice made up floating ice made up floating ice made up roundish nodules, and other kinds of ice. wreck of other kinds wreck of other kinds wreck of other kinds across, the wreckage than 2m (6.5 feet) of fragments not more of fragments not more of fragments not more fragments of ice, of ice. of ice of ice of other forms of ice. across, the wreckage than 2m (6.5ft) than 2 m across, the than 2 m across, the broken off by the Also ice in a of other forms of ice. accross, the wreckage of other wreckage of other attrition of one piece waterlogged state and wreckage of other forms of ice. forms of ice. against another. This appearing of darker forms of ice. Brash Ice may be considered as tone. The American the wreck of other equivalent is generally kinds of ice 'Mush'. In appearance not unlike 'sludge' or 'slush', but brash fragments are of widley varying size Is newly formed on Ice of recent The young ice which Term formerly in use Level ice of more than the sea. Bay ice may formation, so called first forms on the for newly formed one winter's growth, be said to extend because forming surface of the sea in 'level ice', of sufficient which has remained from the first pellicle most readily in bays autumn. thickness to impede unhummocked and of ice, up to a foot in and sheltered spots. or prevent navigation. also becomes Bay Ice thickness [Consists of Preferred alternative nourished by surface 2 categorys, below:] terms are: level, layers of snow. winter or fjord ice. Thickness of ice and Has been used to snow up to about 2 describe heavy land metres (6.5 feet) floes in the Antarctic above sea level. Common Smooth extensive [Bay Ice] sheets Small circular pieces Ice consists of small Small circular floes Small floes of new ice Small floes of new ice Pieces of newly Pieces of newly Predominantly circular Predominantly circular Predominantly circular with raised edges circular pieces with with raised rims; due approximately circular approximately circular formed ice, formed ice, usually pieces of ice from pieces of ice from 30 pieces of ice from 30 raised edges. In a to the break up in a and with raised rims and with raised rims approximately approximately 30cm - 3 m (1-10 cm to 3 m in cm-3 m in diameter ruffled sea the pieces gently ruffled sea of circular, about 1-6 circular, about 30cm feet) in diameter, and diameter, and up to and up to about 10 of bay ice strike each newly formed ice into feet across, and with to 3m (1-10ft) across, up to about 10 cm (4 about 10 cm in cm in thickness, with other on every side, pieces which strike raised rims, due to and with raised rims, inches) in thickness, thickness, with raised raised rims due to the and so become against each other, pieces striking against due to the pieces with raised rims due rims due to the pieces pieces striking against rounded with the and so form turned up each other. striking against each to the pieces striking striking against one one another. It may edges turned up. edges. other, as the result of against one another. another. It may be be formed on a slight wind and swell.