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Natural Resources Canada > Earth Sciences Sector > Priorities > Canada Centre for Remote Sensing
Tour Canada from space Rankin Inlet, Nunavut
 You would probably not guess that this Landsat TM image, which shows ice floes still present in the waters of Rankin Inlet, was recorded in early July! The community of Rankin Inlet, on the west coast of Hudson Bay, is some 515 kilometres north of Churchill, Manitoba. This false-colour image reveals the undisturbed arctic tundra in shades of red while the many lakes and ponds are black. A river emptying into the Inlet is creating a delta. Features like roads and the small air strip are easy to identify as they have disturbed the tundra vegetation.
Question: Why is the ice represented in varying shades of white and grey? [ Answer ]
About this Image
| Location: |
Rankin Inlet, Nunavut |
| NTS map(s): |
55 K/16 (1/50:000) |
 Location Map: |
See a detailed map (1:1M) of the region |
| Image Date: |
July 4, 1994 |
| Satellites/Sensors: |
Landsat Thematic Mapper, Bands 4,3,2 (as R, G, B) |
| Resolution: |
30 m pixels |
| Image Area: |
21km by 21km |
| Image Features: |
Arctic, sea ice, river delta, air field, community of Rankin Inlet, roads, clearings |
| Related Tour Images: |
Mackenzie Delta, Northwest Territories |
| Related Glossary Terms: |
These terms from the CCRS Glossary may help you to understand this image and its interpretation:
false colour, plant reflectance, tone, colour composite |
| Related Tutorial Sections: |
These sections of the "Fundamentals of Remote Sensing" tutorial by CCRS will help you to better understand this image and its interpretation:
2.8 2.12 4.2 5.7
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| Image Credits: |
Received by the Canada Centre for Remote Sensing
Processed by and provided courtesy of RADARSAT International Inc. |
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Additional
Information: | North of the tree-line, this landscape is very different as compared to areas further south, supporting only tundra vegetation (dwarf shrubs, sedges, lichen and heath). This Landsat TM band combination of 4, 3, 2, (R,G,B) is often used for land cover mapping, since the vegetation varieties can be shown clearly as changing tones and colours. In this image, however, the contrast and brightness enhancements have been optimized for showing the details in the ice. As a result, the other features (e.g. vegetation) suffer, and show little variability. A single image can be enhanced in a variety of ways in order to optimize different features. Rankin Inlet is located at the end of the Kudlulik Peninsula. The large lake just north of the air strip is Nipissak Lake. The town lies between Prairie Bay and Melvin Bay. The Barrier Islands are the large, long set of islands to the south west of the town stretching out into the Inlet. Rankin Inlet is part of the new Territory of Nunavut as the Northwest Territories splits into two. |
| Question: |
Why is the ice represented in varying shades of white and grey? |
| Answer: |
By early July, the ice is in an advanced state of melt and decay. The waters of Hudson Bay are typically ice-free from late July to the end of September. The brightest areas indicate thicker ice, possibly with wet snow cover, where strong reflection is occurring. The dark grey edges of the ice floes indicate very thin, slushy ice, where the light absorption properties of the water underneath the ice are strong. |
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