From icebergs melting, are there any new ship paths that have opened up?
That’s a great question! The majority of people who visit Antarctica do so by ship, so vessels play an important role in allowing humans access to the area. While the reduction in Arctic ice has led to the development of new shipping routes in the north, the Arctic is closer to where people live and such routes are therefore useful for trade purposes. Antarctica is far away from where most people live, so the vessels that head south have specific reasons for doing so. They might be undertaking a scientific expedition, taking tourists to experience Antarctica, undertaking permitted fishing in the Southern Ocean, or patrolling to detect illegal fishing. It can be dangerous to sail into the Southern Ocean because of the large waves that form, the notoriously strong winds (such as the furious fifties and screaming sixties), hazards such as icebergs, and the remoteness of the region.
Every year Antarctica doubles in area over the winter, as the sea ice forms on top of the ocean around the continent’s margins. Sea ice is different to icebergs. Icebergs are formed when ice sheets flow down to sea and float, turning into ice shelves, and then large chunks break off at the terminus. It’s sea ice that has a big impact on navigation. When there is less ice, vessels can travel further south along the coastline. This is why Antarctic tour operators tend to offer “Antarctic Circle” voyages that go south of 66 degrees south at the end of the season (February-March), because there is less sea ice around in the late summer and ships can travel further south. It’s also why National Antarctic Programs schedule resupply voyages to coastal stations near the end of summer. You may have seen reports about the discovery of Ernest Shackleton’s vessel Endurance in the Weddell Sea area in 2022 – this area was accessible due to a record low sea ice season, making it possible to travel further south. So to answer the question, changes in sea ice extent from year to year and over longer time scales impact on the accessibility of the region, but this has had more impact on shipping in the north. For up to date sea ice maps of both regions you can visit https://earthobservatory.nasa.gov/world-of-change/sea-ice-antarctic
