In its annual spring field work, the research team from the Icelandic Meteorological Office measured a significant increase in volcanic gasses. The water surface of the subglacial lake within the volcano’s caldera is also high and a jokulhlaup is expected within weeks/months. The jokulhlaups often trigger an eruption, so the volcano is under high surveillance. The last eruption from Grímsvötn occurred in 2011 and emitted about 0.8 km³ of tephra.