Alexa Bank
Alexa Bank is a seamount in Samoa, northwest of Rotuma. The seamount reaches a depth of below sea level and has the appearance of an atoll with a flat top and steep slopes. Some active coral growth takes place at its top, but if it ever was an active atoll it has now drowned. It was probably formed by the Samoa hotspot 24 million years ago, although older volcanism about 40 million years ago has also been identified. Geology and geomorphology Local Alexa Bank rises to depths of , has an eastward elongated flat top and is long and wide, widening towards the west; such dimensions resemble these of Savaii and Upolu in Samoa. The flat top has some features of an atoll including a raised rim, and it may indeed once have been an atoll. The rim is surrounded by a narrow terrace and in turn encloses a much wider terrace, that surrounds the flat top at an average depth of . The northern and southern flanks are formed by steep scarps, with the eastern slope featuring a terrace at depth and the western slope extending as a long volcanic ridge. The upper of the Bank are formed by