Ancient Rocks Unlock Mystery of When Earth's Core Formed (ABC News)
Earth is a magnificent, mysterious place that continues to surprise scientists.
Scientists have long disagreed on when Earth's solid iron inner core was formed, but a new study has zeroed in on its approximate age thanks to clues left in the magnetic signature of ancient igneous rocks.
While
previous estimates have put the inner core at 500 million to 2 billion
years old, a new study from an international team of scientists
published in the journal "Nature" has found the Earth's interior is
somewhere around one to 1.5 billion years old.
NASA Reveals Red Planet Contains Both Frozen, Liquid Water
NASA Reveals What Actually Happens in a Martian Dust Storm
Mars Curiosity Rover Finds Mysterious 'Floating Spoon' on the Red Planet
Scientists
made the determination by examining igneous rocks and determining there
was an increase in Earth's magnetic field between one to 1.5 billion
years, corresponding with the time they believe the inner core began to
freeze due to cooling from the molten outer core.
"This
finding could change our understanding of the Earth’s interior and its
history," Andy Biggin, the lead author of the study who works at the
University of Liverpool's School of Environmental Sciences, said in a
statement.
"The
results suggest that the Earth’s core is cooling down less quickly than
previously thought which has implications for the whole of Earth
Sciences," he said. "It also suggests an average growth rate of the
solid inner core of approximately 1 millimeter per year which affects
our understanding of the Earth’s magnetic field."
Scientists
were also able to create a model with their data, showing that the flow
of energy from Earth's inner core should keep our planet's magnetic
field strong for at lease another one billion years or more.
"This contrasts sharply with Mars
which had a strong magnetic field early in its history which then
appears to have died after half a billion years," Biggin said.
Comments
Post a Comment