Extensive Ice Cap Once Covered Sub-Antarctic Island Of South Georgia
A new study reveals the sub-antarctic island of South Georgia — famous for its wildlife — was covered by a massive ice cap during the last ice age.
(From Science Daily)– The results are published in the journal Nature Communications. South Georgia, the remote UK territory where Sir Ernest Shackleton landed during his dramatic voyage from Antarctica to rescue the team of his Endurance expedition, is home to various species of penguins and seals, and has featured on documentaries including Frozen Planet and Planet Earth II.
The island’s unusual plant communities and marine biodiversity, which are protected within a large Marine Protected Area, have survived and evolved through multiple glacial cycles for tens or even hundreds of thousands of years.
But a research team led by the University of Exeter has discovered that at the peak of the ice age, about 20,000 years ago, ice thickened and extended tens of kilometres from the island — far further than previously believed.
This would have driven its biological communities to small mountain and seabed refuges to survive.
The researchers also found the ice has been sensitive to short-lived cooling and warming — growing and shrinking dramatically as the climate changed.
“Although the island is small framed against Antarctica’s great ice sheets, the discovery of an extensive past ice cap on South Georgia is an important result,” said lead author Dr Alastair Graham, of the University of Exeter.
“The survival of ocean ecosystems is linked heavily to patterns of glaciation, so it is very interesting to know where and how sea-bed creatures lived through the ice age, and how the cycles of ice-cap change have influenced the biodiversity.
“Life must have really only survived at the edges, at and beyond the ice margins.
Read the full article here: https://www.sciencedaily.com/releases/2017/03/170317082446.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fearth_climate%2Foceanography+%28Oceanography+News+–+ScienceDaily%29