Changes in the mass of large ice sheets can also cause small local variations in gravity.
This animation shows that ice lost from West Antarctica has caused a dip in Earth’s gravity.
High-resolution gravity gradients measured by ESA’s GOCE satellite and the NASA–German Grace mission reveal that ice lost between November 2009 and June 2012 left its signature in Earth’s gravity. Yes, we have lost so much ice in Antarctica that it’s causing a dip in Earth’s Gravity.
Well what does this mean actually?

There are slight variations in gravity around the Earth which, are invisible for us but not for our amazing technology! These gravity varies according to the position of the poles and different altitudes, among others. These results link the dip in gravity to the amount of ice melt that they were also measuring over that length of time. This is just another sign showing how quickly the ice sheet in West Antarctica is falling apart.