Friday , July 1 2022

Some of the earth's water came from a stream of hydrogen long ago


Build an ocean

When looking out to the ocean, it's hard to imagine that the swinging body of water is another way. But, says a team of researchers, some of H2O that covers a lot of our planet's surface once again was something very different: a liquid pool in our soaring sunbubble. Only on earth mixed this hydrogen with oxygen to create the water world that we know today.

There are a number of theories about the formation of the world's global sea. Comets that hold a lot of ice could have delivered some of our planet's waters; Asteroids, though they have less water, could have added to the Earth's range as well. "But there is another way of thinking about water sources in the formative days of the solar system," said Steven Desch, a researcher at this team and Professor of Astrophysics at Arizona State University's (ASU) School of Earth and Space Exploration (SESE). a statement. "Because water is hydrogen plus oxygen, and oxygen is plentiful, some hydrogen source may have acted as the water of the earth," said Desch.

Cosmic dust and gas

Hydrogen gas was one of the main ingredients in the solar needle, or the gases and dust that formed the sun and planets of our solar system.

When the planets were formed, hydrogen from sunbathing had been incorporated into their interiors. While most remain locked under, some of it may have combined with oxygen from other materials on earth and proceeded to create the world's global ocean, Desch and his team found.

So, looking for hydrogen in the interior of the earth would give researchers an idea of ​​whether there was enough under the formation of the planet to contribute to the waters of our oceans.

To investigate this theory, the layer saturated the ratio of common hydrogen atoms (H) to "heavy" hydrogen (also called deuterium or D) on earth – the D / H ratio. The water in the global ocean of the earth and it has dissolved in the shell has a D / H ratio of about 150 parts per million (ppm). Asteroid water has a D / H of about 140 ppm and water from comets ranges from 150 ppm to 300 ppm. This makes asteroids (because D / H in comet water is so much higher) a more likely candidate than comets.

Because D / H for hydrogen in the solar needle was very low – 21 ppm – researchers had previously discounted it as a source. Doing that can not be right, says Jun Wu, lead author and assistant researcher at SESE and ASU's Molecular Sciences. The liquid that caused early soil may have gone through a series of geochemical processes that greatly increased the amount of heavy hydrogen it contained, resulting in the D / H ratio we see today. If so, it could have been another source of the water of the earth.

To find out, the team created a computer model of the early earth's mantle and was added to hydrogen to see what happened to it.

In addition to computer modeling, the team took samples of mantle stones. "We calculate how much hydrogen dissolved in the body's mantles could have gotten in their nuclei. Then we compared this with the latest measurements of the D / H ratio in samples from the deep cloak of the earth," says Desch.

The team found, based on dissolved hydrogen, that the soil conceals about two-sea water in the mantle and about four to five in the core. About one of 100 water molecules on earth came from the sun needle, they appreciate. Much of the rest comes from asteroids and some from comets.

The team published this work October 9 in Journal of Geophysical Research.

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