Subscribe free to our newsletters via your
. 24/7 Space News .

Origins and future of Lake Eyre and the Murray-Darling Basin
by Staff Writers
Melbourne, Australia (SPX) May 15, 2015

File image.

Geoscientists have, for the first time, discovered the origins of Australia's two largest basins: Lake Eyre and the Murray-Darling Basin. The research also implies that in 30 million years' time both basins will cease to exist.

Monash University geoscientist Associate Professor Wouter Schellart, and his colleague Professor Wim Spakman from Utrecht University, have discovered how the floor of an entire ocean basin that was destroyed 70 to 50 million years ago off the North coast of New Guinea is currently located at 800-1200km depth below Central and South-eastern Australia.

Using supercomputers, the researchers found that this dense piece of ocean floor material (called a lithospheric slab) is slowly sinking into the Earth's mantle and is responsible for the formation of the Lake Eyre Basin, one of the Earth's largest internally drained basins and home to the lowest point in Australia at 15m below sea level, as well as the Murray-Darling Basin, home to the largest river system in Australia. With a combined surface area exceeding 2 million square kilometres, both basins are located directly above the deep mantle slab.

The research also predicts that in 30 million years from now, when Australia has moved about 1500km northwards, the fossil slab will be located below the Southern Ocean and, as a consequence, the Lake Eyre Basin and Murray Darling Basin will cease to exist.

Using geological and geophysical data from the New Guinea region, Schellart was able to reconstruct the geological evolution of the region over the last 70 million years, including the motion of the tectonic plates and plate boundaries.

He discovered that the occurrence of deep ocean floor rocks, volcanic rocks and deformed rocks, which are currently found in the mountain ranges of New Guinea, point to the existence of a 4000km wide subduction zone. At subduction zones such as these, an oceanic tectonic plate sinks (subducts) into the Earth's interior, the mantle.

With these plate tectonic reconstructions Schellart was able to predict where the fossil subduction zone was during its lifetime some 50-70 million years ago, and therefore where the lithospheric slab disappeared into the mantle.

With a global seismic tomography model that makes use of seismic waves to map the internal structure of the Earth's mantle, Schellart and Spakman were able to identify the fossil slab structure below central and south-eastern Australia at a location and depth predicted by the reconstructions.

"When we first compared the predictions of our reconstructions with the mantle tomography model we were amazed by how perfectly they aligned," Associate Professor Schellart said.

The researchers then developed a computer model to simulate flow in the Earth's mantle to be able to predict the sinking velocity of the fossil slab and to investigate how this sinking might affect the Earth's surface.

They found that although the slab is sinking at a rate of less than 1cm per year, this slow sinking generates a downward flow in the mantle that is sufficient to pull down the Earth's surface and create these huge basins.

"It is incredible to think that tectonic processes that took place millions of years ago at the northern margin of New Guinea are responsible for the landscape we see today in Central and South-eastern Australia," Associate Professor Schellart said.

The research was undertaken with the assistance of resources from the National Computational Infrastructure (NCI), which is supported by the Australian Government. The research was published in the international journal Earth and Planetary Science Letters.

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only


Related Links
Monash University
Tectonic Science and News

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Second quake part of chain reaction: scientists
Paris (AFP) May 12, 2015
The 7.3-magnitude earthquake that struck Nepal on Tuesday, 17 days after a lethal 7.8 temblor, is part of a chain reaction in a notorious seismic hotspot, scientists said. Like buttons popping off one by one from a shirt that is ripped open, a large quake displaces stress to another part of a fault, causing it to rupture, they said. "Large earthquakes are often followed by other quakes, ... read more

NASA's LRO Moves Closer to the Lunar Surface

European Space Agency Director Wants to Set Up a Moon Base

Russia Invites China to Join in Creating Lunar Station

Japan to land first unmanned spacecraft on moon in 2018

Student Mars Rover team will compete in Utah desert

NASA Announces Journey to Mars Challenge

UAE says on track to send probe to Mars in 2021

4,000+ Martian Days of Work on Mars!

Aitech Provides Subsystem and Computing Boards for Commercial Crew

The language of invention: Most innovations are rephrasings of the past

NASA Confirms Electromagnetic Drive Produces Thrust in Vacuum

NASA pushes back against proposal to slash climate budget

3D printer making Chinese space suit parts

Xinhua Insight: How China joins space club?

Chinese scientists mull power station in space

China completes second test on new carrier rocket's power system

Manned mission to ISS to be delayed due to cargo spacecraft's failure

Progress Incident Not Threatening Orbital Station, Work of Crew

Russia loses control of unmanned spacecraft

Japanese astronaut to arrive in ISS in May

'Team Patrick-Cape' supports Pad Abort Test

Local launch expertise; world-wide attention

Successful SpaceX escape test 'bodes well for future'

ILS And Dauria announce Proton/Angara dual launch services agreement

Astrophysicists offer proof that famous image shows forming planets

Astronomers detect drastic atmospheric change in super Earth

New exoplanet too big for its star

Robotically discovering Earth's nearest neighbors

Researchers develop artificial membranes with programmable surfaces

Tiny silicone spheres come out of the mist

See flower cells in 3-D - no electron microscopy required

Researchers match physical and virtual atomic friction experiments

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.