St. Andrew Strait is a volcano in Papua New Guinea that has had eruptions in historical times. The volcano is not linked to any tectonic plates, the volcano is also in an area of very few earthquakes, suggesting that St. Andrew Strait is an Intraplate volcano. It consists of a group of Quaternary volcanic cones that are mainly rhyolitic in composition. The volcanism is curved, suggesting that the volcano has an ancient caldera. The centre of the volcano is Lou Island. Lou island last erupted in 240 BC (give or take 100 years) and 340 AD, both eruptions came from the Bendal volcano. Lou island is the largest eruptive centre of the volcano, with 6 volcanic vents. Also the Pam islands (Pam Lin and Pam Mandian) also contain fresh deposits. Historic eruptions have come from the Tuluman Islands.