ANALYSIS OF ANTARCTIC ICE FRONT CHANGE OVER 50 YEARS OF OBSERVATION FROM SATELLITE REMOTE SENSING

This study analyzes ice front change of Antarctica from 1960s to 2010s based on remote sensing observation. Because the Antarctic ice front is in direct contact with the ocean and atmosphere, its variation is sensitive to the global climate change. Knowledge of the variation of the Antarctic ice front can imply global climate change. This study exploits the orthorectified Radarsat SAR images acquired in 1997, 2002 and 2009 to conduct the continental scale of analysis on the ice dynamics of the Antarctic ice front. The coast line of different period is extracted based on locally adaptive thresholding algorithm. The extracted coast lines representing each period are compared with coast line from 1963 Argon satellite photography to assess the Antarctic ice front dynamics over 50 years of period. The analysis clearly identified that the Antarctic ice front has experienced dramatic changes during the past 50 years. From 1962 to 1997, the Antarctic ice front retreated in general while west Antarctica showed advancing trend and east Antarctica appeared retreating trend. The most advance area is recorded for Ross and Ronne-Filchner ice shelf of west Antarctica whereas Shackleton ice shelf of east Antarctica is the most advanced ice shelf. On the other hand, from 1997 to 2000, the trend was reversed showing retreating trend of west Antarctica and advancing trend of east Antarctica. The overall change can be described as dramatic retreat where retreated area is about four times larger than the advanced area. The Ronne ice shelf is the most retreated ice shelf while Filchner and Amery ice shelves are the most advanced ice fronts during the period. From 2000 to 2009, the net change is negative where the general trend is similar to the 1997-2000 period. However, the net change rate decreased dramatically compare to previous 40 years of period which may imply the ice dynamics of Antarctic ice front is stabilizing.