Unravelling the origins of volcanism along Eastern Australia and the Tasman Sea


Mantle plumes are buoyant upwellings rising from the Earth’s core-mantle boundary to its surface, generating hotspot chains that track the direction of plate motion. Eastern Australia contains three contemporaneous volcanic chains (1 onshore, 2 offshore) that have long been held to be formed by three separate plumes, however, this fails to explain their geochemical similarity and close spacing. Surrounding these plume-related volcanoes are hundreds of smaller volcanic edifices which exhibit no correlation with plate motion. Armed with numerical models of mantle convection, plate reconstructions, seismic tomography, and geochemistry of eruption products, we aim untangle the complex history of volcanism in eastern Australia and offshore. In this talk, I will discuss how plume-slab interaction can lead to plume branching, potentially forming parallel hotspot chains, and the influence of slab flux on driving non-age progressive volcanism.

Image: There are many volcanoes across Australia and Zealandia. Highlights for volcano spotters include: (A) Sawn Rocks in New South Wales, (B) Glass House Mountains and (C) Undara Lava Tubes in Queensland, (D) Mt Gambier in South Australia, (E) Organ Pipes in Victoria and (F) The Nut in Tasmania.


Dr. Ben Mather is a research fellow in the EarthByte Group within the School of Geosciences at The University of Sydney. He is an expert in fusing multi-disciplinary datasets with Earth evolution models to understand the occurrence of enigmatic volcanoes. Related research interests include the cycling of volatiles within the Earth, probabilistic thermal models of the lithosphere to unravel past tectonic and climatic events, and the response of groundwater flow pathways to tectonic forces. A firm supporter of open-source software, Dr. Mather develops computational methods and tools that adhere to Findable, Accessible, Interoperable and Reusable (FAIR) standards and which are hosted in public repositories. He is a vocal advocate for the integral role of geoscience in responding to challenges we face in transitioning to the carbon-neutral economy. Dr. Mather has been interviewed in national and international print media, TV, and radio on a wide variety of subjects including earthquakes, volcanoes, groundwater, and critical minerals.

GitHub: github.com/brmather

Twitter: @BenRMather


This seminar will be streamed using the video conferencing software, Zoom.