A first Plinian stage took place on 19 and 20February, accompanied by an increase of earthquake activity. The first Plinian event lasted for about 20 hours and formed pumice deposits close to the vent that were thick. The pumice was buried by the ash erupted during this stage, which has been recorded as far as Antarctica. This stage of the eruption produced at least of rocks, comprising the bulk of the output from the 1600 eruption. A sustained eruption column about high likely created a mushroom cloud that darkened the sky, obscuring the sun and the stars. Afterwards, collapses in the amphitheatre and within the vent enlarged both features and impeded further eruptive activity. A first pyroclastic flow was deposited already during this time when the column became unstable.