All vegetation on the island was destroyed. Uprooted trees, mixed with pumice ash, washed into the sea and formed rafts up to across. Between 1 and 3 October the British ships and James Sibbald encountered extensive pumice rafts about west of Tambora. Clouds of thick ash still covered the summit on 23 April. Explosions ceased on 15 July, although smoke emissions were observed as late as 23 August. Flames and rumbling aftershocks were reported in August 1819, four years after the event.