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Study Suggests That Life on Earth Began 300 Million Years Earlier Than We Thought

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According to a study published in the journal Proceedings of the National Academy of Sciences (PNAS), after studying carbon samples found in graphite embedded in zircon crystals in Western Australia, researchers believe that life on our planet may have started hundreds of millions of years earlier than previous estimates.

Elizabeth A. Bell and her co-authors explain that "evidence of life on Earth is manifestly preserved in the rock record," but the record of microfossils (so small they require a microscope to see) only goes back so far, to 3.5 billion years ago. Meanwhile, the chemofossil record (chemicals from the decomposition of a once-living organism) dates back to about 3.8 billion years ago, and the rock record to some 4 billion years ago. However, last year, zircon crystals were discovered in the Jack Hills of Western Australia that pre-date the rock record by .4 billion years, making them the oldest known minerals on the planet.

Bell and her team studied more than 10,000 Jack Hills zircon crystals and discovered the graphite and carbon samples in a "crack-free" region of the minerals. "We used the caesium ion beam to drill through the [zircon] surface and into the graphite, such that the graphite was never exposed to contaminants prior to analysis," she told Scientific American. The researchers believe that the graphite was "incorporated during crystallization of this igneous zircon." That means that if the carbons were produced by live organisms, then a "terrestrial biosphere" may have formed around 4.1 billion years ago—that's roughly 300 million years earlier than scientists previously thought.

Bell also told Scientific American that while the isotope ratio of the carbon found (which is used as an "indicator of life" in rocks) could be a result of processes that don't involve living organisms, the conditions in which the graphite was discovered would make those alternative processes "incredibly complicated, perhaps unfeasibly so."

The next step in confirming that the carbon was produced by living organisms would be to find and study more samples in the Jack Hills zircon crystals.

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AI Could Help Scientists Detect Earthquakes More Effectively
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Thanks in part to the rise of hydraulic fracturing, or fracking, earthquakes are becoming more frequent in the U.S. Even though it doesn't fall on a fault line, Oklahoma, where gas and oil drilling activity doubled between 2010 and 2013, is now a major earthquake hot spot. As our landscape shifts (literally), our earthquake-detecting technology must evolve to keep up with it. Now, a team of researchers is changing the game with a new system that uses AI to identify seismic activity, Futurism reports.

The team, led by deep learning researcher Thibaut Perol, published the study detailing their new neural network in the journal Science Advances. Dubbed ConvNetQuake, it uses an algorithm to analyze the measurements of ground movements, a.k.a. seismograms, and determines which are small earthquakes and which are just noise. Seismic noise describes the vibrations that are almost constantly running through the ground, either due to wind, traffic, or other activity at surface level. It's sometimes hard to tell the difference between noise and legitimate quakes, which is why most detection methods focus on medium and large earthquakes instead of smaller ones.

But better understanding natural and manmade earthquakes means studying them at every level. With ConvNetQuake, that could soon become a reality. After testing the system in Oklahoma, the team reports it detected 17 times more earthquakes than what was recorded by the Oklahoma Geological Survey earthquake catalog.

That level of performance is more than just good news for seismologists studying quakes caused by humans. The technology could be built into current earthquake detection methods set up to alert the public to dangerous disasters. California alone is home to 400 seismic stations waiting for "The Big One." On a smaller scale, there's an app that uses a smartphone's accelerometers to detect tremors and alert the user directly. If earthquake detection methods could sense big earthquakes right as they were beginning using AI, that could afford people more potentially life-saving moments to prepare.

[h/t Futurism]

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Stefan Flöper, Wikimedia Commons // CC BY-SA 3.0
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Why There's a 4-Ton Steel Ball Making Mini-Earthquakes in Germany
Stefan Flöper, Wikimedia Commons // CC BY-SA 3.0
Stefan Flöper, Wikimedia Commons // CC BY-SA 3.0

An earthquake is caused by the shifting of tectonic plates, the pieces of Earth's crust that make up the surface of the planet. But humans have figured out how to create artificial earthquakes without relying on Mother Nature. YouTube personality Tom Scott recently visited the world's oldest working seismic station in Göttingen, Germany, to experience one of these mini-earthquakes in person.

Wiechert'sche Erdbebenwarte Göttingen is home to a 4-ton steel ball that can be hoisted 46 feet in the air. When dropped, the impact sends shock waves through the ground. The power to manufacture earthquakes on demand helps the team calibrate their seismographs, but there's another reason the rig was set up: It proved the theory that artificial quakes can be used to measure the earth underground.

German geophysicist Emil Wiechert got the idea a century ago. By using seismic meters to measure the reflections of waves rocking an area, he hypothesized that he would end up with an accurate sketch of what the world looked like below. The steel ball was set up in Göttingen in 1903, and it proved his theory to be correct.

More sophisticated instruments are used to measure subterranean landscapes today, but the mini-earthquake maker still functions as well now as it did 100 years ago. You can see it in action in the video below.

[h/t Tom Scott]

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