By Lorena Stancu
The bed of Pine Island Glacier (PIG) in West Antarctica was discovered to have an unexpectedly diverse relief which could slow down ice retreat in the face of global warming.
The frozen continent may look smooth on the surface, but underneath the blocks of ice there is a diverse landscape of hills and mountains reaching up to 400 metres. Using radar technology and 3D imagery models, a team of British scientists led by Dr Rob Bingham from Edinburgh University could see what lies under the ice. “In one place at the bed of Pine Island, the ice mounts a cliff that’s almost vertical”, he told the BBC.
The Pine Island Glacier (PIG) is a mass of ice in West Antarctica. This ice sheet, as large as two thirds the size of UK, has attracted scrutiny because it contributes to a 10th of the rise of global sea levels. Coming into contact with warmer waters the glaciers are progressively and irreversibly melting from beneath, which is a cause of great concern for environmentalists.
The PIG has been reportedly shrinking since the 1940s, retreating more than 30 km in the last 25 years. Satellite imagery has enabled scientists to see that the glacier is suffering major changes, but more factors needed to be taken into consideration to understand the scale and pace of the change. One of these factors is the ground or bed on which the glacier is sitting.
“The research begins the process of measuring those bed properties in a much more correct and robust way”, the lead author says in a BBC report.
The results surprised the scientists themselves: “We’ve imagined the shape of the bed at a smaller scale than ever before and the message is really quite profound for the ice flow and potentially for the retreat of the glacier”. The diversity in the sub-glacial landscape represents a new variable, which could be essential in projecting accurate levels of global sea level rise from the ice sheet loss.
The team scanned 1,500 square km, which accounts for 15% of the PIG. According to the authors, this study constitutes the “largest and most spatially detailed observational data”.
However, observational data from beneath the Antarctic ice streams remains limited in academia. The remoteness and low temperatures of the place make it one of the most hostile environments, and indeed quite challenging for scientists.
Human resilience and ingenuity continues to defy this however. The next project under the programme iStar will look at a neighbouring Twaites Glacier, which is also a major contributor to rising sea levels.