Identifying Fast Ice in Antarctica
14.07.2010 - Water & Oceans, Ice & Snow, Antarctic
A new model developed by PhD student Alex Fraser from the Institute for Marine and Antarctic Studies and the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) in Australia could help scientists gain better insight into the extent and variability of fast ice (stationary sea ice attached to the continent or grounded icebergs). The new model, which has the ability to detect changes in Antarctic fast ice as well as the physical impacts of fast ice on glaciological processes, will also help in the study of the biological impacts of fast ice.
The new method used NASA's MODIS (MODerate resolution Imaging Spectroradiometer) satellite images to map the distribution of fast ice in East Antarctica from 10°W to 172°E between 2000 and 2008. By singling out the clear, could-free parts of the original images and combining them, Fraser obtained a series of 159 composite images covering the nine-year period, enabling him to differentiate fast ice from pack ice.
The results show that the Indian Ocean Sector (from 20°E to 90°E) of Antarctica had witnessed a significant increase in fast ice extent, while the Western Pacific Ocean Sector (between 90°E and 160°E) has experienced no similar increase. Yet in order to be able to identify a clear trend in fast ice extent, the study would require a record spanning more than nine years.
