in West Antarctica of the first decade of the twenty-first century. This mass loss is more likely to be due to increased melting of the ice shelves because of changes in ocean circulation patterns (which themselves may be linked to atmospheric circulation changes that may also explain the warming trends in West Antarctica). Melting of the ice shelves in turn causes the ice streams to speed up. The melting and disappearance of the floating ice shelves will only have a small effect on sea level, which is due to salinity differences. The most important consequence of their increased melting is the speed up of the ice streams on land which are buttressed by these ice shelves. Recent observations A group of scientists with the University of California updated previous results ranging from 1979 to 2017, which improved time series for more accurate results. Their article, published January 2019, covered four decades of information in Antarctica, revealing the total mass loss which increased gradually per decade. 40 ± 9 Gt/y from 1979 to 1990, 50 ± 14 Gt/y from 1989 to 2000, 166 ±18 Gt/y from 1999 to 2009 and finally 252 ±26 Gt/y from 2009 to 2017. The majority of mass loss was in the Amundsen Sea sector, which experienced loss as high as 159 ±8 Gt/y. There are areas which have not experienced much loss at all, such as East Ross ice shelf. This improved study revealed an acceleration of near 280% over the span of four decades. The study questions previous hypotheses, such as the belief that the heavy melt began in the 1940s to 1970s, suggesting that more recent anthropogenic actions have caused accelerated melt. See also Filchner-Ronne Ice Shelf Geography of Antarctica Greenland ice sheet Ice shelf List of glaciers in the Antarctic Ross Ice Shelf Subglacial lake References External links 'Incredible' rate of polar ice loss alarms scientists (2014) Environment of Antarctica Glaciology Ice sheets of Antarctica