Description :
Consolidated ice cover (left) and large cracks (right) typically present themselves in RADARSAT-2 multi-polarization image composites as (near) white, linear features. Consolidated ice can form during early winter when high winds break the initial ice cover and cause it to amass in a particular location where it refreezes. Recurring expansion and contraction of ice cover as a result of temperature swings may lead to the formation of large cracks. Both impact the trafficability of ice roads. The presence of consolidated ice is often considered helpful because it is thicker whereas the existence of large cracks -
especially when wet - is deemed unhelpful since it increases the breakthrough risk.
Photographe :
van der Sanden, J J
Collection :
Ressources naturelles Canada
Haute-résolution :
4.92 MB
4000x3000 pixels
180 ppi (jpeg)
Nota :
Depending on the weather conditions, ice cover can grow the full extent of the available water depth and become attached to the lake bottom. Unfortunately, bottom-fast ice cannot be discriminated from floating columnar ice in individual RADARSAT-2 multi-polarization composite images because both ice types display black. Discrimination of the two ice types is facilitated by a times series of RADARSAT-2. The measured backscatter level
decreases when the ice becomes bottom-fast and increases when the ice grows. Similar to shorelines, bottom-fast ice formations jeopardize the trafficability of ice roads because their presence increases the risk of traffic induced ice cover failures. However, the presence of bottom-fast ice is more difficult to ascertain.
Géographie :
5044; Tibbitt-to-Contwoyto Winter Road; Territoires du Nord-Ouest; 2020-338.JPG; Nunavut