samoa is located just northeast of the northern corner of the tonga trench, where the pacific plate is subducting. this proximity to the trench is probably the reason why the older volcanic islands all display recent volcanic activity, such as activity from 1905-1911 on savaii and originally led to proposals of a non-hotspot origin of the samoa islands. however, the islands' formation shows an eastward trend and evidence of age progression, which has been interpreted as reflecting an age progressive chain of volcanoes that begins at vailulu'u and at malumalu seamount. the malulu seamount and rose island east of vailulu'u do not appear related to the samoa hotspot system. on the other side of the volcanic chain are the seamounts lalla rookh bank, combe bank and alexa bank which are older products of the samoa hotspot.