• May 30th, 2019

Ancient, rocky boundary under Antarctic could be interfering with ice melt

A tectonic boundary believed to be created when the Antarctic continent was formed has just been discovered and it could be determining how ice is formed or melts, show research published in the journal Nature Geoscience.

Kirsty Tinto, a research scientist at the Lamont-Doherty Earth Observatory at Columbia University says this boundary could be protecting the ice shelf's grounding line, the point at which it extends to the sea floor. This boundary could be preventing warm ocean water away from the East Antarctic side but could be causing ice to melt along the shelf's easterly edge.

The rocky structure, at the centre of the Ross ice shelf - a vast sheet of ice covering 185,000 square miles (480,000 square kilometres) which is hundreds of feet thick - was discovered by Tinto and her team using data from an from an airplane-based tool called IcePod. Its instruments collect information on the thickness of the ice shelf and structure and detect magnetic and gravitational anomalies from the rock underlying the ice shelf.

The research team believes that this boundary could be shaping the seafloor beneath the ice as it (seafloor) is deeper, at 2,198 feet (670 metres), on average. To the west, the average depth is 1,837 feet (560 m), on average.

The Ross shelf is stable at the moment and will remain so if climate change remains moderate. However in the face of extreme climate change it could mean a faster decline in sea ice or decrease in cloud cover that could change global weather patterns.