Taking the pulse of the global ocean

sediments_currents_global_oceanWhen organic particles sink from the surface ocean to the seafloor, a small but significant proportion of atmospheric carbon is stored away. Adriana Dutkiewicz and colleagues at the University of Sydney and Data61/CSIRO have now used global data sets collected over decades combined with cutting-edge big data analysis to understand how this process depends on surface ocean environments.   … Read more…

Commotion in the deep Southern Ocean

SE_Ind_ridge_labelled
Bathymetry of the Southeast indian Ridge, where a major sediment accumulation rate anomaly has been linked to lateral changes in the vigour of bottom water flow.

A team led by the University of Sydney School of Geosciences has found an 8,000-km long sediment pile-up in the middle of the Southern Ocean, making this feature unique in the world. Their study was published today in the leading international journal Geology. … Read more…

The pains and strains of a continental breakup

View of Australia’s western continental margin, looking eastwards from the Indian Ocean. Every now and then in Earth’s history, a pair of continents draws close enough to form one. There comes a time, however, when they must inevitably part ways. Now scientists at Australia’s EarthByte research group, in collaboration with the German Research Centre for … Read more…

Solving Earth’s giant jigsaw puzzle of tectonic plates

plate-tesselation
Earth’s plate tesselation through time (150 Myr ago to present)

Plate tectonics drives earthquakes and volcanism, forms precious mineral deposits and controls the planet’s long-term carbon cycle.   But why do we have just a few large plates, and many tiny plates?  Does it matter? These questions have now been answered in a French-Swiss-Australian collaborative paper led by PhD student Claire Mallard at the Univ. Lyon, published on 15 June 2016 in the journal Nature. The paper includes Nicolas Coltice (Lyon), EarthByters Dietmar Müller and Maria Seton, and Paul Tackley (ETH). 

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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 – 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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Virtual Time Machine Of Earth’s Geology Now In The Cloud

gravity_grid_180my_agoHow did Madagascar once slot next to India? Where was Australia a billion years ago?

Cloud-based virtual globes developed by a team led by University of Sydney geologists mean anyone with a smartphone, laptop or computer can now visualise, with unprecedented speed and ease of use, how the Earth evolved geologically. 

Reported today in PLOS ONE, the globes have been gradually made available since September 2014. Some show Earth as it is today while others allow reconstructions through ‘geological time’, harking back to the planet’s origins.  

Uniquely, the portal allows an interactive exploration of supercontinents. It shows the breakup and dispersal of Pangea over the last 200 million years. It also offers a visualisation of the supercontinent Rodinia, which existed 1.1 billion years ago. Rodinia gradually fragmented, with some continents colliding again more than 500 million years later to form Gondwanaland.   

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Ancient Indian Ocean microplate discovery dates birth of Himalayas

Mammerickx Microplate

Mammerickx MicroplateAn international team of scientists led by the University of Sydney’s School of Geosciences has discovered that the crustal stresses caused by the initial collision between India and Eurasia cracked the Antarctic Plate far away from the collisional zone and broke off a fragment the size of Tasmania in a remote patch of the central Indian Ocean.

The ongoing tectonic collision between the two continents produces enormous geological stresses that build up along the Himalayas and lead to numerous earthquakes every year – but now scientists have unravelled how stressed the Indian Plate became 47 million years ago when its northern edge first collided with Eurasia. … Read more…

Big Data Maps World’s Ocean Floor

Lithology globe Aus Ant viewScientists from the University of Sydney’s School of Geosciences have led the creation of the world’s first digital map of the seafloor’s geology.

It is the first time the composition of the seafloor, covering 70 percent of the Earth’s surface, has been mapped in 40 years; the most recent map was hand drawn in the 1970s.

Published in the latest edition of Geology, the map will help scientists better understand how our oceans have responded, and will respond, to environmental change. It also reveals the deep ocean basins to be much more complex than previously thought.

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