According to the Icelandic news today geological scientists in Iceland are expecting a eruption and a glacier flood from Grímsvötnum at any time and without a any warning. But last week they did detect harmonic tremors on the SIL station that is on Grímsfjall volcano. It is not known if the harmonic tremors where created by water or by magma.
Currently the Grímsvötn lake is full and is ready to burst at any time without warning. Because of that scientists and Iceland Met Office have increased the monitoring of Grímsvötn and Grímsfjall volcano. It has been six years since the last eruption at Grímsfjall (2004) and it only where six years before that eruption (1998).
Iceland News. Please use Google translate.
Enn skelfur jörðin undir Vatnajökli (Rúv.is)
Búast við hlaupi hvenær sem er (mbl.is)