Sea-level rise between 2005 and 2011 was predominately caused by the melting of mountain glaciers and polar ice sheets, reports a paper published online this week in Nature Geoscience.The findings suggest that sea level rose by 2.4 mm per year over this period.

Jianli Chen and colleagues used gravity data from the GRACE satellites to estimate changes in ocean mass between 2005 and 2011.They show that the ocean mass increased over this period, resulting in a 1.8 mm rise in sea level per year, largely due to the melting of ice sheets in Greenland and Antarctica, and mountain glaciers.In addition, they assessed changes in ocean density using data from a network of ocean floats.They estimate that a reduction in density over the same period led to a sea-level rise of 0.6 mm per year.Total sea-level rise obtained from these two techniques provides independent support for the estimate of 2.39 mm per year derived from satellite altimeters.