A series of satellite images has highlighted the dramatic retreat of Stephenson Glacier on the eastern side of Heard Island from 1947 to 2014 (Figure ANT9). Comparing aerial surveys in 1947 with 1988 SPOT satellite imagery shows that Stephenson Glacier decreased by 4.6 square kilometres (km2; 18 per cent) between 1947 and 1988. By 1997, it had lost a further 2.1 km2 (10 per cent), which opened up a 6.5 km2 lagoon (Ruddell 2006). By 2000, there was a further retreat of 0.1 kilometres (Ruddell 2006). This shrinkage was not steady—the northern margin experienced a dramatic acceleration (to about 100 metres per year) in retreat from 1987 to 2000 (Kiernan & McConnell 2002). Retreat continued and, in 2006, a waterway opened between the 2 proglacial lagoons (lagoons formed during the retreat of a melting glacier) that had formed near the terminus of Stephenson Glacier. Between 2006 and the early 2010s, the retreat continued. The waterway increased in size (to 8.7 km2 in 2012 and 9.3 km2 in 2014), and the glacier area decreased by 1 km2 between 2012 (10.9 km2) and 2014 (9.9 km2) (Donoghue 2016).