Close X
Friday, November 29, 2024
ADVT 
Health

'Nuclear winter' wiped out dinosaurs 66 mn years ago: Study

Darpan News Desk IANS, 13 May, 2014 02:06 PM
    In a first physical evidence that a sudden dip in temperatures wiped out dinosaurs, a team of scientists has revealed that a massive asteroid hit the earth 66 million years ago, causing “nuclear winter” and the ultimate demise of giant animals.
     
    Global temperatures suddenly plummeted following the “Chicxulub” impact off Mexico's Yucatan Peninsula, researchers said.
     
    The “Chicxulub” impact is likely to have lowered global sea surface temperatures by as much as seven degrees Celsius.
     
    The evidence was hidden in Brazos River region of Texas. Sedimentary rocks were analysed from the same age as the asteroid impact, containing layers of broken shells.
     
    “The global 'impact winter' perturbed a relatively stable, warm climate and likely represented a major stress factor for life on earth,” said Johan Vellekoop from Utrecht University in the Netherlands.
     
    The “winter” is thought to have lasted no more than two to three decades but that was long enough to wipe out the dinosaurs, flying and swimming reptiles, and many other forms of life, researchers noted.
     
    As seen in computer simulations, sunlight reaching the earth's surface might have been reduced to around 20 percent of its normal level after the impact.
     
    The first hours of the impact were marked by earthquakes, tsunamis and global wildfires.
    Next, dust and sulphur droplets would have collected in the atmosphere and blocked out the sun's rays.
     
    The 'dark phase' would have caused a global collapse of terrestrial and marine food webs, said the study that appeared in the journal Proceedings Of The National Academy Of Sciences.

    MORE Health ARTICLES

    Ancient kitten-sized predator found!

    Ancient kitten-sized predator found!
    A kitten-sized but formidable hunter preyed on animals of its size in Bolivia about 13 million years ago, researchers have found.

    Ancient kitten-sized predator found!

    Teen depression may kill love life even in middle-age

    Teen depression may kill love life even in middle-age
    Negative emotions suffered when one was young can have a lasting grip on love relationships well into middle-age, new research says.

    Teen depression may kill love life even in middle-age

    Scientists rewrite code of life with 'alien' DNA

    Scientists rewrite code of life with 'alien' DNA
    In a major breakthrough that could re-write the history of life on earth, scientists have successfully added an alien pair of DNA "letters" (or bases) to create the first "semi-synthetic" bacterium.

    Scientists rewrite code of life with 'alien' DNA

    Now, a DNA tool to spot cancer

    Now, a DNA tool to spot cancer
    Detecting cancer could soon become a lot easier as scientists have used DNA to develop a tool that detects and reacts to chemical changes caused by cancer cells.

    Now, a DNA tool to spot cancer

    What you were waiting for! A device that detects pee in pool

    What you were waiting for! A device that detects pee in pool
    Those who have a habit of peeing in a swimming pool, beware. Here comes a device glows green the moment it detects traces of human waste in water.

    What you were waiting for! A device that detects pee in pool

    Do humans have spiders' genes?

    Do humans have spiders' genes?
    Not only the spiderman, even you may share certain genomic similarities with spiders, a study that for the first time sequenced the genome of a spider has revealed.

    Do humans have spiders' genes?