A United States research scientist is warning that two new undersea volcanos near Manu'a in American Samoa may pose a future tsunami threat.
Hubert Staudigel from the Scripps Institution of Oceanography says in four years, the Nafanua volcano has grown 1,000 feet.
Mr Staudigel told the San Diego Union Tribune that seismic activity may cause undersea landslides, resulting in a tsunami.
Scientists say there is evidence to suggest the volcanoes may be a better archetype of an island hot-spot system than Hawaii, and is an ideal spot to study plate tectonics.
Last year, hundreds of foot-long eels were discovered in the area, surviving in rock caves and crevices.