Published online by Cambridge University Press: 01 May 2009
An underwater study of recent submarine lava flows on São Miguel (Azores) suggests that the island has subsided by as much as 9 m relative to sea level over the last few thousand years. A spectacular system of overlapping lava arch structures occur immediately below the ancient sea level, and they are thought to have formed when tongues of molten lava flowed over a steep autochthonous submarine scree slope. The scree was subsequently removed by strong longshore currents and wave action.