File:A-68A and South Georgia Island (MODIS 2020-12-01).jpg

English: Complex currents and strong wind continued to push Iceberg A-68A closer to South Georgia Island through November 2020. On November 25, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of A-68A sitting approximately 176 miles (275 km) southeast of the island.

Iceberg A-68 made headlines in July 2017 when the Delaware-sized block of ice broke from the Larsen C Ice Shelf on the Antarctic Peninsula. After a smaller piece of the berg broke away, the large “mother” berg was given the name A-68A, indicating it was the largest piece of the original iceberg. A-68A now measures about 94 miles (151 km) long and 30 miles (48 km) wide—comparable to South Georgia’s length of 104 miles (167 km) and width of 23 miles (37 km).

In just over three years at sea, Iceberg A-68A has drifted generally northward, passing the tip of the Antarctic Peninsula and floating into “Iceberg Alley”— a path taken by more than 90 percent of all Antarctic icebergs from the Weddell Sea. Most bergs follow the currents that flow southward past South Georgia, drifting well east of the island before catching a counter-current that carries them northwestward into warmer waters, where they ultimately melt. A few bergs drift into a different current and pass the island off the western shore. Even fewer are trapped by complex currents in this part of the South Atlantic and end up “grounding” (getting stuck) on the shallow shelves near the island or grind to a halt on the island itself— scenarios that could mean trouble for the island’s abundant wildlife if the berg blocks the foraging routes of penguins and seals, or if it damages the population of krill.

Even as A-68A draws close to South Georgia, scientists still have difficulty predicting the path the iceberg will ultimately take. On November 5, A-68A was about 300 miles (500 km) to the southwest of the islands, drifting on a course that prompted concerns about grounding, despite the statistical probability of the berg taking the more common southern route safely around South Georgia. By November 30, the gap had closed to about 141 miles (227 km) as A-68A drifted on a wobbling path, tracking just slightly westward as the berg’s eastern tip dipped first southward and then northward by eddies and currents. NASA’s satellites will continue to monitor A-68A as it continues its perilous journey towards South Georgia Island.