BANGALORE: The world’s coastlines may soon change with experts predicting a huge rise in the sea level with the ongoing collapse of the West Antarctic ice sheet.
Experts predict the rise in sea level at around four metres and this may force people living low-lying areas like the coasts of south China and north-east America to vacate their homes.
Separate studies by two groups of scientists in the Unites States said the West Antarctic ice sheet is melting at an alarming rate. The studies were published in journals Geophysical Research Letters and Science. One group used a numerical model and found that the rate of glacial melting would increase rapidly after the 21st century. The study estimated the sea levels to rise at 1 mm a year in the next 200 to 900 years.
The other group has measured retreating glaciers using Earth Remote Sensing and satellite radar interferometry from 1992 to 2011. They found that the Pine Island glacier has retreated 31 km at its centre, with the biggest retreat in 2005-2009, when the glacier was un-grounded from its ice plain.
The Thwaites glacier has retreated 14 km in its fast-flow core and around 1-9 km along its sides. The Haynes glacier has retreated around 10 km along its flanks. The Smith/Kohler glacier has retreated the most — 35 km along its ice plain, with its ice shelf pinning points vanishing. All these glaciers are on the West Antarctic ice shelf.
Prof Govindaswamy Bala at the Centre for Atmospheric and Oceanic Studies, Indian Institute of Science, told Express, “The studies refer to the West Antarctic ice sheet, not the whole Antarctic ice sheet. The West Antarctic sheet is known to be influenced by climate changes. The East Antarctic sheet is unlikely to melt significantly any time soon.”
He agreed with the time period projected for the ice sheet’s collapse. He added, “According to the study, the Thwaites glacier is holding on now because of an underwater ridge in the ocean. Unlike the mountain glaciers, the terminal point for glaciers in the Antarctic is the ocean. When the ocean waters become warm because of climate change, glacial retreat will be accelerated.”