Parts of two volcanic zones of Iceland are placed under Vatnajökull, ie. the very active East Volcanic Zone (connected to rifting at the divergent plate boundary in Iceland), responsible for the highest number of eruptions after deglaciation and with the mantle plume probably under Bárðarbunga, ie. under Vatnajökull. More than 80 eruptions occurred during the last 800 years in Vatnajökull.There is also the much less active Öraefi Volcanic Belt, a flank zone mostly under the eastern part of Vatnajökull.It is thought that due to climate change, Vatnajökull has lost about 10% of its mass since the end of the 19th century. Measurements showed an accentuated and even accelerating rate of glacio-isostatic uplift. This could lead to increased magma production (so called decompression melt production), because the pot lid formed by the glaciers and their weight will be absent in the future, and eruption frequency could increase as a consequence.