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The temporal and spatial variability of the Antarctic coastline is a clear indicator of change in extent and mass balance of ice sheets and shelves. In this study, the Canny edge detector was utilized to automatically extract high-resolution information of the Antarctic coastline for 2005, 2010, and 2017, based on optical and microwave satellite data. In order to improve the accuracy of the extracted coastlines, we developed the Canny algorithm by automatically calculating the local low and high thresholds via the intensity histogram of each image to derive thresholds to distinguish ice sheet from water. A visual comparison between extracted coastlines and mosaics from remote sensing images shows good agreement. In addition, comparing manually extracted coastline, based on prior knowledge, the accuracy of planimetric position of automated extraction is better than two pixels of Landsat images (30 m resolution). Our study shows that the percentage of deviation (<100 m) between automatically and manually extracted coastlines in nine areas around the Antarctica is 92.32%, and the mean deviation is 38.15 m. Our results reveal that the length of coastline around Antarctica increased from 35,114 km in 2005 to 35,281 km in 2010, and again to 35,672 km in 2017. Meanwhile, the total area of the Antarctica varied slightly from 1.3618 × 10⁷ km² (2005) to 1.3537 × 10⁷ km² (2010) and 1.3657 × 10⁷ km² (2017). We have found that the decline of the Antarctic area between 2005 and 2010 is related to the breakup of some individual ice shelves, mainly in the Antarctic Peninsula and off East Antarctica. We present a detailed analysis of the temporal and spatial change of coastline and area change for the six ice shelves that exhibited the largest change in the last decade. The largest area change (a loss of 4836 km²) occurred at the Wilkins Ice Shelf between 2005 and 2010.

Item Type:	Refereed Article
Keywords:	Antarctica, digital coastline, SAR analysis, Antarctic coastline, coastline extraction, remote sensing, Canny algorithms, ice shelves
Research Division:	Earth Sciences
Research Group:	Other earth sciences
Research Field:	Other earth sciences not elsewhere classified
Objective Division:	Environmental Policy, Climate Change and Natural Hazards
Objective Group:	Understanding climate change
Objective Field:	Effects of climate change on Antarctic and sub-Antarctic environments (excl. social impacts)
UTAS Author:	Heil, P (Dr Petra Heil)
ID Code:	137627
Year Published:	2019
Web of Science® Times Cited:	11
Deposited By:	CRC-Antarctic Climate & Ecosystems
Deposited On:	2020-02-24
Last Modified:	2022-08-29
Downloads:	9 View Download Statistics