Researchers have examined 3.8 billion year old minerals from
Greenland which are derived from the Earth’s primordial oceans in order
to approximate the ancient water budget. (Credit: Image courtesy of
University of Copenhagen)
Investigating the history of water on Earth is critical to understanding
the planet's climate. One central question is whether Earth has always
had the same amount of water on and surrounding it, the same so-called
"water budget." Has Earth gained or lost water from comets and
meteorites? Has water been lost into space? New research into Earth's
primordial oceans conducted by researchers at the Natural History Museum
of Denmark at the University of Copenhagen and Stanford University
revisits Earth's historical water budget.
The results have just been published in the Proceedings of the National Academy of Sciences.
Water accounts for about ½ of a thousandth of Earth's total mass,
despite the fact that roughly 70% of the planet's surface is covered by
this substance so vital to survival. Indeed, water is a relatively "rare
substance" on our "Blue Planet."
Where does water come from?
"One of the absolutely most intriguing things about Earth is that
there are oceans of water and that the presence of liquid water has
enabled the existence of life on Earth. Therefore, questions concerning
how Earth got its oceans, where the water came from and -- whether we
are losing or gaining water from space -- are fundamental questions in
the understanding of the Earth's history," says Emily Pope of the Nordic
Center for Earth Evolution at the Natural History Museum of Denmark,
University of Copenhagen.
Earth's "little bit" of water is divided among a variety of
reservoirs. Therefore, a fairly accurate assessment of how much water
currently exists on Earth can be made. But now, Emily Pope and her
colleagues at the Natural History Museum of Denmark and Stanford
University have also been able to determine that liquid water was also
in existence upon the young Earth, billions of years ago. And, more
consequentially, they have been able to approximate the ancient water
budget.
The researchers have done this by examining 3.8 billion year old
minerals from Greenland which are derived from Earth's primordial
oceans.
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