Landslide fan. Colluvial fan
301
Area which has been subjected to hill levelling
51
An area with a series of small elongate ridges, produced at tidally influenced ice sheets margin or floating icebergs grounding line
971
An area of the seabed with depressions formed by bottom currents. They have an almost flat bottom often consisting of coarse-grained sediments that provide high backscatter in acoustic data, and current-/wave ripples are often observed. The size of the depressions varies, but they can be up to 3 km long, 300 m wide, and 1 m deep. Current depressions have been found, for example, on Sveinsgrunnen off Troms and in the North Sea.
64
Area with iceberg ploughmarks
63
Area with landforms formed by landslide material
42
Area with landforms formed by quick clay landslide masses
43
Area with landforms formed by rockslide material
41
Area with landforms formed by unspecified slide material
40
Area with landforms and sediments resulting from melting of dynamically stagnant (dead) glacier ice. Can include both till and glaciofluvial deposits.
8
A positive topographic element which primarily consists of clay, often in connection with the seepage of gas on the seafloor
904
Area where surface of the seabed has been changed by dredging
955
Streamlined ridge in sediment, oriented parallel to the ice-flow direction.
3
Area with many drumlins of similar orientation.
4
Dune field (or sand waves)
61
Distinct ridge in sorted surficial sediment, resulting from deposition in tunnels or cavities in a glacier. The line symbol for esker (12) can be used in combination with this polygon to emphasize the position and orientation of the ridge.
1
Excavation/gravel pit
957
Area with elongated parallel ridges and grooves on a surface. Ridges and grooves are oriented parallel to the direction of former ice movement. Low relief and little width in relation to length.
953
Area with landforms formed by landslide material
53
Semi-circular mounds or domes with steep sides and an uneven surface. Gas hydrate pingos are formed when gas flowing up from deeper layers under the seabed accumulates in pore spaces in sediments below the surface. Gas hydrate pingos occur in areas that are under high pressure and low temperature, e.g. at great depths and in cold regions, e.g. Storfjordrenna and Storbanken in the Barents Sea.
915
Hole (depression) in the surface formed during ice movement and rip off and removal of big, often sheet-formed slabs of its subsurface
913
Narrow valley with steep sides, formed by erosion in bedrock or consolidated sediments by a river or a subaquatic/submarine stream
350
Depression in surficial sediment formed by the grounding of an iceberg
910
Wedge-shaped ridge that is formed at the front of a glacier during periods of standstill or minor advances of a glacier
970
Ice marginal deposit of either till or glaciofluvial material or a combination of these
963
Moraine ridge formed along an ice margin. Includes end, lateral and terminal moraines.
962
Ridge shaped moraine deposit
964
Area characterized by mounds and ridges of varying length and orientation.
2
Local elevation on the seabed consisting of unconsolidated sediments
914
Area of a bog with peat covered, ice-cored mounds. Formed through growth of ground ice which does not melt during summer.
33
Area with polygon patterned surface formed through frost action. This pattern can be formed by ice-wedge polygons or by stone sorting from freeze-thaw processes.
32
Clear ridge formation on the seabed of unspecified origin
965
Coalescent sinuous ridges, comprised mainly of till, oriented transverse to ice-flow direction. Often situated in close relation to drumlins.
12
Area with sediment waves
959
Landscape formed by a landslide; can include slide hollow, slide run and slide fan
951
Area with tussocks resulting from frost activity in peat.
31