The gradual colonisation of the ash laid down during the emergence of Anak Krakatoa in Indonesia following the catastropic eruption of Krakatoa itself at the end of the 19th century,Surtesey, the Icelandic island that emearged in the 1960s,and the varioud eruptive stages that have built up Nea Kameni in the Santorini caldera in Greece since the 18th century are all sources of evidence that show how coastal lithseres develop through time.