The Australian-New Zealand IODP Consortium Workshop

The recent Australian-New Zealand IODP Consortium workshop organised jointly with the School of Geosciences, University of Sydney was the largest Australasian workshop for scientific ocean drilling on record with about 100 attendees from 12 countries, including Australia, New Zealand, New Caledonia, Japan, India, Germany, Great Britain, France, Denmark, Sweden, Canada, and the USA, with the youngest attendee being only … Read more…

Dynamic topography of passive continental margins and their hinterlands since the Cretaceous

Even though it is well accepted that the Earth’s surface topography has been affected by mantle-convection induced dynamic topography, its magnitude and time-dependence remain controversial.  The dynamic influence to topographic change along continental margins is particularly difficult to unravel, because their stratigraphic record is dominated by tectonic subsidence caused by rifting. We follow a three-fold … Read more…

Large fluctuations of shallow seas in low-lying Southeast Asia driven by mantle flow

Zahirovic, S., Flament, N., Müller, R.D., Seton, M., and Gurnis, M. (2016). Large fluctuations of shallow seas in low-lying Southeast Asia driven by mantle flow. Geochemistry, Geophysics, Geosystems. doi:10.1002/2016GC006434 Large fluctuations of shallow seas in low-lying Southeast Asia driven by mantle flow

A rapid burst in hotspot motion through the interaction of tectonics and deep mantle flow

Hassan, R., Müller, R.D., Gurnis, M., Williams, S.E. and Flament, N. (2016). A rapid burst in hotspot motion through the interaction of tectonics and deep mantle flow. Nature, 533, 239-242. doi:10.1038/nature17422 A rapid burst in hotspot motion through the interaction of tectonics and deep mantle flow

How the Hawaiian-Emperor seamount chain got its spectacular bend

In a paper published in Nature, Rakib Hassan with fellow EarthByters Dietmar Müller, Simon E. Williams & Nicolas Flament, and Caltech’s Michael Gurnis, proposed a solution to a long standing geological mystery – how the distinct bend in the Hawaiian-Emperor Seamount Chain came to be. Using NCI’s Raijin supercomputer, the research team simulated flow patterns in the Earth’s mantle over the past 100 million years. The convection model suggests that the history of subduction has a profound effect on the time-dependent deformation of the edges of the Large Low-Shear Velocity Province (LLSVP) under the Pacific. The Hawaiian plume originates from the edge of this province and the southward migration of the plume during the formation of the Emperor chain reflects the migration of the northern edge of the LLSVP before ~47 million years ago. 
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Geologists Discover How Australia’s Highest Mountain Formed

Eastern_australia_topographyCongratulations to Prof Dietmar Müller, Dr Nicolas Flament, Dr Kara Matthews, Dr Simon Williams, and Prof Michael Gurnis on their paper recently published in Earth and Planetary Science Letters. Their paper, Formation of Australian continental margin highlands driven by plate-mantle interaction, has featured in a variety of Australian and international media outlets.

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Geologists Discover How Australia’s Highest Mountain Formed – Media Release

Eastern_australia_topographyGeologists from the University of Sydney and the California Institute of Technology have solved the mystery of how Australia’s highest mountain – Mount Kosciusko – and surrounding alps came to exist.

Most of the world’s mountain belts are the result of two continents colliding (including the Himalayas) or volcanism. The mountains of Australia’s Eastern highlands – stretching from north-eastern Queensland to western Victoria – are an exception. Until now no one knew how they formed.

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Earth and Planetary Science Letters – Formation of Australian continental margin highlands driven by plate–mantle interaction

Müller, R. D., Flament, N., Matthews, K. J., Williams, S. E., & Gurnis, M. (2016). Formation of Australian continental margin highlands driven by plate–mantle interaction. Earth and Planetary Science Letters, 441, 60–70. http://dx.doi.org/10.1016/j.epsl.2016.02.025 Formation of Australian continental margin highlands driven by plate–mantle interaction

Geophysical Research Letters – Mantle-induced subsidence and compression in SE Asia since the early Miocene

Yang, T., M. Gurnis, and S. Zahirovic (2016), Mantle–induced subsidence and compression in SE Asia since the early Miocene, Geophysical Research Letters, doi: 10.1002/2016GL068050.  Mantle-induced subsidence and compression in SE Asia since the early Miocene

History and current advances in reconstructing the Earth through deep geological time

Rodinia 1000 Ma

Rodinia 1000 MaTime machine: History and current advances in reconstructing the Earth through deep geological time – an article on Quartz by Steve LeVine. The article is a review of the development of ideas and technologies in reconstructing the Earth through deep time, aimed at understanding supercontinent assembly, breakup and dispersal, starting with Alfred Wegener. The article focusses on research activities in the context of the IGCP 648 project ‘Supercontinent Cycles and Global Geodynamics‘ led by Zheng-Xiang Li. The piece provides some historical context, and highlights the work of a number of leading scientists, postdoctoral researchers and PhD students currently involved in this work.  … Read more…

Deep Carbon Observatory (DCO) proposal funded

Global plate reconstruction

A Deep Carbon Observatory (DCO) Proposal, designed to study the interaction of subduction zones with carbonate platforms through time in terms of CO2 cycles, submitted to the Smithsonian Institution and prepared to a large extent by Dr Sabin Zahirovic and EarthByte Research Assistant Jodie Pall, was successful, raising $US36k. The DCO actually doubled our proposed budget from … Read more…

Influence of subduction history on South American topography

Case 4 paleotopography 16MaCitation
Flament, N., Gurnis, M., Müller, R. D., Bower, D. J., & Husson, L. (2015). Influence of subduction history on South American topography. Earth and Planetary Science Letters, 430, 9-18. doi: 10.1016/j.epsl.2015.08.006.

Abstract
The Cenozoic evolution of South American topography is marked by episodes of large-scale uplift and subsidence not readily explained by lithospheric deformation. The drying up of the inland Pebas system, the drainage reversal of the Amazon river, the uplift of the Sierras Pampeanas and the uplift of Patagonia have all been linked to the evolution of mantle flow since the Miocene in separate studies. Here we investigate the evolution of long-wavelength South American topography as a function of subduction history in a time-dependent global geodynamic model. This model is shown to be consistent with these inferred changes, as well as with the migration of the Chaco foreland basin depocentre, that we partly attribute to the inboard migration of subduction resulting from Andean mountain building. … Read more…

Earth and Planetary Science Letters – Influence of subduction history on South American topography

Case 4 paleotopography 16Ma

Flament, N., Gurnis, M., Müller, R. D., Bower, D. J., & Husson, L. (2015). Influence of subduction history on South American topography. Earth and Planetary Science Letters, 430, 9-18. doi: 10.1016/j.epsl.2015.08.006. Influence of subduction history on South American topography

Geochemisty, Geophysics, Geosystems – Provenance of plumes in mantle convection models

Hassan, R., Flament, N., Gurnis, M., Bower, D. J., & Müller, D. (2015). Provenance of plumes in global convection models. Geochemistry, Geophysics, Geosystems. doi: 10.1002/2015GC005751. Provenance of plumes in global convection models

Geophysical Research Letters – Ridge subduction sparked reorganisation of the Pacific plate-mantle system 60-50 million years ago

Seton, M., Flament, N., Whittaker, J., Müller, R. D., Gurnis, M., & Bower, D. J. (2015). Ridge subduction sparked reorganization of the Pacific plate‐mantle system 60–50 million years ago. Geophysical Research Letters, 42(6), 1732-1740. doi: 10.1002/2015GL063057. Ridge subduction sparked reorganization of the Pacific plate‐mantle system 60–50 million years ago

Physics of the Earth and Planetary Interiors – Assimilating lithosphere and slab history in 4-D Earth models

Bower, D. J., Gurnis, M., & Flament, N. (2015). Assimilating lithosphere and slab history in 4-D Earth models. Physics of the Earth and Planetary Interiors, 238, 8-22. doi: 10.1016/j.pepi.2014.10.013. Assimilating lithosphere and slab history in 4-D Earth models

Earth and Planetary Science Letters – Topographic assymetry of the South Atlantic from global models of mantle flow and lithospheric stretching

Flament, N., Gurnis, M., Williams, S., Seton, M., Skogseid, J., Heine, C., & Müller, R. D. (2014). Topographic asymmetry of the South Atlantic from global models of mantle flow and lithospheric stretching. Earth and Planetary Science Letters, 387, 107-119. dx.doi.org/10.1016/j.epsl.2013.11.017. Topographic asymmetry of the South Atlantic from global models of mantle flow and lithospheric stretching … Read more…

Topographic asymmetry of the South Atlantic from global models of mantle flow and lithospheric stretching

Flament et al EPSL 2014 - FigureCitation
Flament, N., Gurnis, M., Williams, S., Seton, M., Skogseid, J., Heine, C., & Müller, R. D. (2014). Topographic asymmetry of the South Atlantic from global models of mantle flow and lithospheric stretching. Earth and Planetary Science Letters, 387, 107-119. dx.doi.org/10.1016/j.epsl.2013.11.017.

Abstract
The relief of the South Atlantic is characterized by elevated passive continental margins along southern Africa and eastern Brazil, and by the bathymetric asymmetry of the southern oceanic basin where the western flank is much deeper than the eastern flank. We investigate the origin of these topographic features in the present and over time since the Jurassic with a model of global mantle flow and lithospheric deformation. The model progressively assimilates plate kinematics, plate boundaries and lithospheric age derived from global tectonic reconstructions with deforming plates, and predicts the evolution of mantle temperature, continental crustal thickness, long-wavelength dynamic topography, and isostatic topography. … Read more…

Scientific Drilling – Exploring new drilling prospects in the Southwest Pacific

Arculus, R., D’Hondt, S., Exon, N., Foster, C., Gallagher, S. J., Gurnis, M., … & Wallace, L. (2014). Exploring new drilling prospects in the Southwest Pacific. Scientific Drilling, 17, 45-50. doi: 10.5194/sd-17-45-2014. Exploring new drilling prospects in the southwest Pacific

A review of observations and models of dynamic topography

Citation
Flament, N., Gurnis, M., & Müller, R. D. (2013). A review of observations and models of dynamic topography. Lithosphere, 5(2), 189-210. doi: 10.1130/L245.1

Flament-et-al_fig1Summary
The topography of Earth is primarily controlled by lateral differences in the density structure of the crust and lithosphere. In addition to this isostatic topography, flow in the mantle induces deformation of its surface leading to dynamic topography. This transient deformation evolves over tens of millions of years, occurs at long wavelength, and is relatively small (<2 km) in amplitude. Here, we review the observational constraints and modeling approaches used to understand the amplitude, spatial pattern, and time dependence of dynamic topography. … Read more…

Understanding the deep driving forces of Earth’s large-scale topography through time

Global paleogeography figureProject Summary
Continents and sedimentary basins through time record fundamental Earth system cycles, reflecting environmental change, migration of fauna and flora and shifting coastlines. It was originally thought that successive advances and retreats of shallow inland seas mainly reflect global sea level variations (eustasy). It is now well known in principle that large-scale surface morphology such as the high topography of the East African Rift, the low-lying Amazon River Basin and the southwest to northeast tilt of the Australian continent are strongly controlled by processes deep within the Earth, but progress has been slow in quantifying the magnitude and time-dependence of these relationships. … Read more…

Global continental and ocean basin reconstructions since 200 Ma

Plate reconstruction 200Ma-1Global plate motion models provide a spatial and temporal framework for geological data and have been effective tools for exploring processes occurring at the earth’s surface. However, published models either have insufficient temporal coverage or fail to treat tectonic plates in a self-consistent manner. They usually consider the motions of selected features attached to tectonic plates, such as continents, but generally do not explicitly account for the continuous evolution of plate boundaries through time. … Read more…

Earth-Science Reviews – Global continental and ocean basin reconstructions since 200 Ma

Seton, M., Müller, R. D., Zahirovic, S., Gaina, C., Torsvik, T., Shephard, G., … & Chandler, M. (2012). Global continental and ocean basin reconstructions since 200Ma. Earth-Science Reviews, 113(3), 212-270. doi:10.1016/j.earscirev.2012.03.002. Download the paper – pdf

6th eResearch Australasia Conference – Evolution of Earth’s topography from models of global mantle flow and lithospheric deformation

Flament, N., Gurnis, M., Williams, S.E., Seton, M. and Müller, R.D., (2012). Evolution of Earth’s topography from models of global mantle flow and lithospheric deformation, 6th eResearch Australasia Conference , Sydney, 28 Oct-1 Nov 2012. Download the paper – pdf

Dynamic topography and anomalously negative residual depth of the Argentine Basin

Shephard 2012 Argentine Basin-1A substantial portion of Earth’s topography is known to be caused by the viscous coupling of mantle flow to the lithosphere but the relative contributions of shallow asthenospheric flow versus deeper flow remains controversial. The Argentine Basin, located offshore of the Atlantic margin of southern South America, is one of the most anomalously deep ocean regions as it is significantly deeper than its age would suggest. … Read more…