Why are we doing this?
In a handful of locations on Earth, hot material rises from deep within the Earth to create lines of volcanoes such as the Hawaiian-Emperor Seamount Chain. We aim to test if the Tasmantid and Lord Howe Seamount chains, hidden in the seas off eastern Australia, should be included in this rare group and if the Louisiade Plateau to the north could have formed from the massive flood of basaltic lava triggered when a rising plume reaches the surface.
Understanding intraplate volcanism
One of the world’s most extensive intraplate volcanic regions is located in Eastern Australia, including the world’s longest continental hotspot trail and two parallel trails offshore (Tasmantid and Lord Howe Seamount chains). Hotspot trails are thought to arise from mantle plumes, whose episodic eruptions have caused environmental crises affecting the world’s atmosphere (release of gas and aerosols), biosphere (mass extinctions) and hydrosphere (altering ocean circulation and chemistry). Identifying mantle plume eruptions in the geological record provides us with a window into the deep Earth.
We will use the Coral Sea as a natural laboratory to test competing hypotheses for how deep mantle plumes have influenced the evolution of the Australian plate. In addition, using data-science approaches, we will assess whether the mantle that these volcanoes is sampling is anomalous and what influence neighbouring plate boundaries have on mantle chemistry.
Impacts of this research
This project seeks to determine the extent of plume activity in the Coral Sea and explore the factors controlling the geochemical make-up of the mantle, will facilitate breakthroughs in answering some of the most challenging questions in Earth Sciences such as how the deep Earth communicates with the surface, what controls the heterogeneity in mantle chemistry and the validity of the mantle plume hypothesis itself.
Our results will have implications for natural hazards, deep-sea resources, and habitat mapping. Mapping submarine seamount morphologies coupled with age-dating of volcanoes provides constraints on the degradation of volcanic edifices through time and their tsunamigenic potential in modern analogue settings. Our petrological and geochemical analysis of volcanism will provide an exploration framework for unexplored but potentially lucrative seafloor mineral resources, which are an important source of critical metals necessary for our renewable energy future. The geomorphological study of seamounts, naturally important habitats for open-ocean ecosystems, may help identify areas of significant conservation value.