Card #19: Melting Ice Sheets
Greenland and Antarctica are ice sheets (or continental glaciers). If they were to completely melt, they will cause the sea level to rise by 7 metres for Greenland and 54 metres for Antarctica. During the last ice age, ice sheets were so much larger that the sea level was 120 metres lower than today.
These illustrations represent the gain or loss of mass of the caps, indicated in centimetres of water per year (cm of water/year) and measured gravimetrically. In blue the mass gain (because it snows more) and in red the losses (glaciers flow faster towards the ocean).
An ice cap (or ice sheet) is a continental-scale mass of land ice, thick enough (between 1,600 and 6 400 m thick) that covers most of the underlying rock formations. There are currently only two major ice sheets, one in Greenland and one in Antarctica.
We will speak here of melting of the ice caps when the total mass of ice has decreased over the period under consideration, whatever the processes involved.
To go further
Between 2006 and 2015, the loss of ice from the ice caps is:
- 278 billion tonnes per year for Greenland
- 155 billion tonnes per year for the Antarctic.
For some great graphics that illustrate Earth's ice loss, check out this article from ESA.