Subscribe free to our newsletters via your
. Space Industry and Business News .




EARLY EARTH
Tropical collapse caused by lethal heat
by Staff Writers
Leeds UK (SPX) Oct 19, 2012


illustration only

Scientists have discovered why the 'broken world' following the worst extinction of all time lasted so long - it was simply too hot to survive.

The end-Permian mass extinction, which occurred around 250 million years ago in the pre-dinosaur era, wiped out nearly all the world's species. Typically, a mass extinction is followed by a 'dead zone' during which new species are not seen for tens of thousands of years. In this case, the dead zone, during the Early Triassic period which followed, lasted for a perplexingly long period: five million years.

A study jointly led by the University of Leeds and China University of Geosciences (Wuhan), in collaboration with the University of Erlangen-Nurnburg (Germany), shows the cause of this lengthy devastation was a temperature rise to lethal levels in the tropics: around 50-60 degrees C on land, and 40 degrees C at the sea-surface.

Lead author Yadong Sun, who is based in Leeds while completing a joint PhD in geology, says: "Global warming has long been linked to the end-Permian mass extinction, but this study is the first to show extreme temperatures kept life from re-starting in Equatorial latitudes for millions of years."

It is also the first study to show water temperatures close to the ocean's surface can reach 40 degrees C - a near-lethal value at which marine life dies and photosynthesis stops. Until now, climate modellers have assumed sea-surface temperatures cannot surpass 30 degrees C. The findings may help us understand future climate change patterns.

The dead zone would have been a strange world - very wet in the tropics but with almost nothing growing. No forests grew, only shrubs and ferns. No fish or marine reptiles were to be found in the tropics, only shellfish, and virtually no land animals existed because their high metabolic rate made it impossible to deal with the extreme temperatures. Only the polar regions provided a refuge from the baking heat.

Before the end-Permian mass extinction the Earth had teemed with plants and animals including primitive reptiles and amphibians, and a wide variety of sea creatures including coral and sea lillies.

This broken world scenario was caused by a breakdown in global carbon cycling. In normal circumstances, plants help regulate temperature by absorbing Co2 and burying it as dead plant matter. Without plants, levels of Co2 can rise unchecked, which causes temperatures to increase.

The study, published [19 October 2012] in the journal Science, is the most detailed temperature record of this study period (252-247 million years ago) to date.

Sun and his colleagues collected data from 15,000 ancient conodonts (tiny teeth of extinct eel-like fishes) extracted from two tonnes of rocks from South China. Conodonts form a skeleton using oxygen.

The isotopes of oxygen in skeletons are temperature controlled, so by studying the ratio of oxygen isotopes in the conodonts he was able to detect temperature levels hundreds of millions of years ago.

Professor Paul Wignall from the School of Earth and Environment at the University of Leeds, one of the study's co-authors, said: "Nobody has ever dared say that past climates attained these levels of heat.

Hopefully future global warming won't get anywhere near temperatures of 250 million years ago, but if it does we have shown that it may take millions of years to recover."

The study is the latest collaboration in a 20-year research partnership between the University of Leeds and China University of Geosciences in Wuhan. It was funded by the Chinese Science Foundation.

'Lethally hot temperatures during the early Triassic greenhouse' by Yadong Sun (University of Leeds and China University of Geosciences), Michael Joachimski (University Erlangen-Nurnberg, Germany), Paul B. Wignall (University of Leeds), Chunbo Yan (China University of Geosciences), Yanlong Chen (University of Graz, Austria), Haishui Jiang (China University of Geosciences, Lina Wang (China University of Geosciences) and Xulong Lai (China University of Geosciences) is published in Science on 19 October 2012.

.


Related Links
University of Leeds
Explore The Early Earth at TerraDaily.com






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

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








EARLY EARTH
16 million-year-old amber specimen reveals unknown animal behaviors
Manchester UK (SPX) Oct 18, 2012
Stunning images, including video footage, from a CT scan of amber have revealed the first evidence of any creature using an adult mayfly for transport. Researchers at the University of Manchester say this 16 million-year-old hitchhiker most likely demonstrates activity that is taking place today but has never previously been recorded. Entombed in amber the tiny springtail can be seen resti ... read more


EARLY EARTH
Apple opens biggest Asian store in Beijing

Will Apple go for 'kill' with iPad Mini?

Taiwan temple to launch 'divine advice' app

Kennedy Supporting Effort to Develop Satellite Servicing Capabilities

EARLY EARTH
$15M order for Harris tactical radios

SPAWAR Atlantic taps Engility

Northrop Grumman Begins Production of EHF SatCom System for B-2 Bomb

Mutualink Selects Benchmark to Manufacture Interoperable Communications Systems on Global Scale

EARLY EARTH
AFSPC commander convenes AIB

Proton Lofts Intelsat 23 For Americas, Europe and Africa Markets

India to launch 58 space missions in next 5 years

SpaceX Dragon Successfully Attaches To Space Station

EARLY EARTH
NASA's WISE Colors in Unknowns on Jupiter Asteroids

Indra Technology Supports Management And Control Of New Galileo Satellites

Testing of Galileo satellite navigation system can begin

Two more satellites for the Galileo system

EARLY EARTH
Boeing EMARSS Risk Reduction Prototype Makes First Flight

NASA Seeks Student Experiments For 2013 High-Altitude Scientific Balloon Flight

Raytheon-led team graduates first Afghan Air Force pilots on Warfighter FOCUS program contract

Second UK F-35 And Marine Corps F-35B Delivered To Eglin

EARLY EARTH
Breakthrough offers new route to large-scale quantum computing

Bus service for qubits

Developing the next generation of microsensors

ORNL study confirms magnetic properties of silicon nano-ribbons

EARLY EARTH
Landsat Science Team to Help Guide Next Landsat Mission

TerraSAR-X images Bonneville salt flats

Earth Observation Commercial Data Market Remains Strong Despite Slowdown in 2011

Antarctic Rift Subject of International Attention

EARLY EARTH
New methods might drastically reduce the costs of investigating polluted sites

Pollution row strangles Italian steel giant ILVA

S. Korean villagers evacuate after toxic leak

Council of war gathers for world's biodiversity crisis




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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