Expedition to Enigmatic Submarine Volcanoes
Extinct underwater volcanoes in the Tasman Sea off Australia. Image credit: Lara Kalnins
In August 2019, we will spend 28 days on Australia’s research vessel, the R/V Investigator, studying two chains of extinct submarine volcanoes in the Tasman and Coral Seas off the east coast of Australia. The primary goal of the voyage, led by the University of Tasmania, is to understand if the two chains, together with a nearby large underwater plateau, could represent a rare example of warm material upwelling from deep inside the Earth and reaching the surface to form volcanoes.
To make this area even more unusual, instead of a single line of volcanoes, this area has two underwater chains and one on land, all parallel and all formed at the same time: it’s as though the upwelling material split into three branches. To help us understand both how the volcanoes form and how material flows in the Earth’s mantle, we will be studying how this splitting might have occurred and remained stable for at least 30 million years. Did the upwelling material encounter obstacles such as pieces of subducted tectonic plate that forced it to change path? Did the thick, deep ‘keels’ of the continental areas sticking down into the mantle split the flow, like water flowing around a rock?