Mars attracts: how Earth’s planetary interactions drive deep-sea circulation

12 March 2024, The University of Sydney Media Release Giant whirlpools in warming oceans could mitigate Gulf Stream stagnation Geoscientists at Sydney and Sorbonne have identified a 2.4-million-year cycle in the geological record that show the energy of deep-sea currents wax and wane as oceans cool and warm. Earth’s distance to Mars varies between 55 … Read more…

What made Earth a giant snowball 700m years ago? Scientists have an answer

8 February 2024, University of Sydney Media release Historically low volcanic emissions and weathering events seem likely cause Dr Adriana Dutkiewicz was inspired during a field trip to the Flinders Ranges to find out how volcanic activity turned our blue dot to an ice covered planet. Together with Professor Dietmar Muller and the EarthByte group, … Read more…

Environmental stability on Earth allowed marine biodiversity to flourish

Modern ocean biodiversity, which is at its highest level ever, was achieved through long-term stability of the location of so-called biodiversity hotspots, regions of especially high numbers of species, scientists have found. The findings, published in Nature, were reached through a pioneering model that reconstructs the diversity of marine animals from their origin – some … Read more…

Plate tectonic carbon cycle explains how Earth maintains a Goldilocks climate

Earth’s hot and cold climates driven by tectonic plate speeds A new study has revealed how the plate tectonic carbon cycle maintains a “Goldilocks climate” on Earth that is neither too hot nor too cold. It is now established that CO2 emissions from burning fossil fuels are driving atmospheric CO2 above 400 parts per million … Read more…

Groundwater ‘superhighway’ modelled along Australia’s east coast

When floodwaters recede, where do they go? By Loren Smith University of Sydney researchers have modelled water-storing aquifers that perform a natural balancing act: they absorb water during floods and supply water during drought. Yet human intervention is limiting their function. University of Sydney researchers have identified a groundwater ‘superhighway’ along Australia’s east coast. Stretching from … Read more…

Global warming speeds up currents in the ocean’s abyss

University of Sydney media release University of Sydney scientists have used the geological record of the deep sea to discover that past global warming has sped up deep ocean circulation. This is one of the missing links for predicting how future climate change may affect heat and carbon capture by the oceans. Circulation of the … Read more…

Volcanoes acted as a safety valve for Earth’s long-term climate

Volcanoes acted as a safety valve for Earth’s long-term climate The natural weathering of rocks on Earth’s surface over time is a crucial process for removing CO2 from the atmosphere Researchers have now used artificial intelligence to study interactions between land, sea and the atmosphere to determine the biggest drivers of this process over the … Read more…

How marine snow cools the planet

University of Sydney scientists have modelled how carbonate accumulation from ‘marine snow’ in oceans has absorbed carbon dioxide over millennia and been a key driver in keeping the planet cool for millions of years. Researchers in the School of Geosciences have mapped out how carbonate formations have helped regulate Earth’s temperature over 120 million years. … Read more…

Does the sea level or the sun drive volcanic seafloor topography?

Modelling shows what causes abyssal hills 2.5km below sea level Computer modelling shows climate- and sea-level cycles are not responsible for the ‘hills’ and ‘valleys’ at the bottom of the sea – a hypothesis that would have mapped a path to uncovering Earth’s climate history. Half a century after discovering how plate tectonics works, the … Read more…

How seafloor weathering drives the slow carbon cycle

A previously unknown connection between geological atmospheric carbon dioxide cycles and the fluctuating capacity of the ocean crust to store carbon dioxide has been uncovered by two geoscientists from the University of Sydney. Prof Dietmar Müller and Dr Adriana Dutkiewicz from the Sydney Informatics Hub and the School of Geosciences report their discovery in the … Read more…

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…

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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…

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The pains and strains of a continental breakup

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 Geosciences, have revealed the underlying mechanics of a continental breakup when this … 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…

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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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