Magma chamber evolution during the 1650 AD Kolumbo eruption provides clues about past and future volcanic activity

Kolumbo submarine volcano lies 7 km NE of Santorini caldera and its last eruption which occurred in 1650 AD, caused damage and casualties to the nearby islands. Here a simple model of a chamber, containing silicic magma underlain by a smaller quantity of mafic magma, is utilised in order to understand the chamber behaviour during the 1650 AD eruption. Results show that in order to reproduce the duration (83-281 days) and the dense rock equivalent volume ([Formula: see text]) of the eruption, initial overpressure in the chamber should be around 10 MPa and the mafic magma should occupy up to 5% of the chamber volume. It is found that the time needed to inject mafic magma equal to 1-15% of the chamber volume varies between 1.4-13.7 ka, if the radius of the chamber is about 1500 m as inferred from tomographic images. These long recurrence times agree well with the small number of eruptions ([Formula: see text]) within a period of > 70 ka and suggest that an eruption in the near future is unlikely. Volcanic activity at Kolumbo is probably triggered by a combination of exsolved volatiles and a small but steady influx of mafic melt in the chamber.