Ice displacements observed by Synthetic Aperture Radar near the New Siberian Islands
Shinya Kakuta
Japan Marine Science and Technology Center
2-15 Natsushima, Yokosuka 237-0061 JAPAN
Tel: 81-468-67-3463;
Fax: 81-468-65-3202
kakutas@jamstec.go.jp
Shoji Takeuchi
Remote Sensing Technology Center, Roppongi First Building, Tokyo, Japan
We investigated the region near the islands by RADARSAT SCANSAR,
because preliminary RGPS (RADARSAT Geophysical Processor System) data set does not show data near the New Siberian Islands. Every week from December 1996 through April 1997, we obtained a 500 km * 500 km RADARSAT SCANSAR image in the Western half of the East Siberian Sea including the New Siberian Islands. According to ice charts of National Ice Center, US A, fast ice extended between the New Siberian Island and the Siberian Continent and 20 to 30 km northward offshore from the New Siberian Island. Except fast ice, dark cracks of the RADARSAT images may be regarded as thin-ice or open-water with 80 to 100 % of ice concentration (compactness), where brine may be generated. The dark cracks are sometimes wider than 30 km. The pattern of the dark cracks narrower than a few km was changing drastically throughout the period of our RADARSAT observation. We also found that the pattern of the dark cracks wider than 10 km changed drastically, from December 29, 1996 to February 1, 1997 and from 14 to 28 April 1997. In contrast, a stable 50 km long dark portion with 90 to 100 % of ice concentration is located on the edge of land-fast ice 70 km northeast of the New Siberian Island throughout the period of our RADARSAT observation.
