Undersea Internet Cables Could Be Key to the Future of Earthquake Detection

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Considering that 70 percent of the planet is covered by oceans, we don't have all that many underwater earthquake sensors. Though there's plenty of seismic activity that happens out in the middle of the ocean, most detection equipment is located on land, with the exception of a few offshore sensor projects in Japan, the U.S., and Canada.

To get better earthquake data for tremors and quakes that happen far from existing sensors, a group of scientists in the UK, Italy, and Malta suggest turning to the internet. As Science News reports, the fiber-optic cables already laid down to carry communication between continents could be repurposed as seismic sensors with the help of lasers.

The new study, detailed in a recent issue of Science, proposes beaming a laser into one end of the optical fiber, then measuring how that light changes. When the cable is disturbed by seismic shaking, the light will change.

This method, which the researchers tested during earthquakes in Italy, New Zealand, Japan, and Mexico, would allow scientists to use data from multiple undersea cables to both detect and measure earthquake activity, including pinpointing the epicenter and estimating the magnitude. They were able to sense quakes in New Zealand and Japan from a land-based fiber-optic cable in England, and measure an earthquake in the Malta Sea from an undersea cable running between Malta and Sicily that was located more than 50 miles away from the epicenter.

A map of the world's undersea cable connections with a diagram of how lasers can measure their movement
Marra et al., Science (2018)

Seismic sensors installed on the sea floor are expensive, but they can save lives: During the deadly Japanese earthquake in 2011, the country's extensive early-warning system, including underwater sensors, was able to alert people in Tokyo of the quake 90 seconds before the shaking started.

Using existing cable links that run across the ocean floor would allow scientists to collect data on earthquakes that start in the middle of the ocean that are too weak to register on land-based seismic sensors. The fact that hundreds of thousands of miles of these cables already crisscross the globe makes this method far, far cheaper to implement than installing brand-new seismic sensors at the bottom of the ocean, giving scientists potential access to data on earthquake activity throughout the world, rather than only from the select places that already have offshore sensors installed.

The researchers haven't yet studied how the laser method works on the long fiber-optic cables that run between continents, so it's not ready for the big leagues yet. But eventually, it could help bolster tsunami detection, monitor earthquakes in remote areas like the Arctic, and more.

[h/t Science News]

Archaeologists Uncover World's Oldest Known Brewery in Israel

People have been knocking back beers for 13,000 years, according to new archaeological findings out of the Middle East. As Science magazine reports, evidence of wheat and barley-based beer was found inside stone mortars carved into the floor of a cave near Haifa, Israel.

The Raqefet Cave was used as a burial site by the Natufians, a group of semi-nomadic hunter-gatherers who were also responsible for the world’s oldest known bread, which was discovered in Jordan in July. These findings challenge previous evidence that traced the origin of beer back just 5000 years.

Beer was also previously believed to be merely a by-product of bread-making, but archaeologists say that isn’t necessarily the case. Instead, researchers believe beer may been served during ritual feasts “to venerate the dead and/or to enhance group cohesion among the living,” researchers wrote in their paper, published in the Journal of Archaeological Science: Reports.

Remarkably, the Stanford University researchers who made this discovery weren't even looking for evidence of alcohol. “We did not set out to find alcohol in the stone mortars, but just wanted to investigate what plant foods people may have consumed because very little data was available in the archaeological record,” Li Liu, a professor of Chinese archaeology at Stanford, said in a statement.

Researchers theorize that beer brewing may have inspired the Natufians to cultivate cereals in the region, but it’s not currently known whether beer or bread came first. The mortars dug into the cave floor were reportedly used for storing and pounding wheat and barley, as well as brewing beer.

The beverage wasn’t exactly what we know as beer today, though. According to the BBC, the prehistoric beer was “gruel-like” and similar to porridge. It was likely weaker than modern beer, too.

[h/t Science]

Newly Uncovered Galileo Letter Details How He Tried to Avoid the Inquisition

Galileo Before The Papal Tribunal by Robert Henry. Hulton Archive, Getty Images
Galileo Before The Papal Tribunal by Robert Henry. Hulton Archive, Getty Images

Galileo Galilei was one of the Roman Catholic Inquisition’s most famous targets. As a result of his outspoken support for the theory that all the planets, Earth included, revolve around the Sun, the Catholic Church charged him with heresy and he spent the last years of his life under house arrest. Galileo was well aware that he was on the Church’s hit list, and a newly discovered letter shows that at one point, he tried to tone down his ideas to avoid persecution, according to Nature and Ars Technica.

The letter in question, written in 1613, solves a long-held mystery for Galileo scholars. It was found in the library of the Royal Society, where it has been for at least 250 years.

Galileo’s beef with the Catholic Church came about because of his support for heliocentrism—the idea that the solar system centers around the Sun—as advocated in Nicolaus Copernicus’s book De Revolutionibus. Galileo’s scientific writings clearly endorsed Copernicus’s theory of the world, including in personal correspondence that was widely disseminated, and in some cases, he directly questioned the scientific merit of Biblical passages.

In 1613, Galileo wrote to a friend and former student named Benedetto Castelli who was then teaching mathematics at the University of Pisa. The letter was a long treatise on Galileo’s thoughts on Copernicus’s ideas and religion, arguing that science and astronomy should not be overpowered by religious doctrin . (He would later expand this into his Letter to the Grand Duchess Christina.) As with many of Galileo’s writings at the time, the letter was copied and disseminated widely, and eventually, a friar named Niccolò Lorini forwarded it to the Inquisition in Rome in 1615.

This is where things get tricky. Galileo claimed that the version of the letter Lorini sent was doctored to be more inflammatory. He sent a less controversial version of the letter to a friend, saying that it was the original document and should be forwarded to the Vatican, essentially to clear his name. But scholars have never been able to be totally sure if he was telling the truth about the letter being doctored.

This newly discovered letter suggests that he was lying, and that he himself was looking to tone down his rhetoric to appease the Catholic Church and keep authorities from quashing the spread of heliocentric ideas. The original copy found in the Royal Society archives shows changes to the wording in what appears to be Galileo’s handwriting. The seven-page letter, signed “G.G.,” includes changes like swapping the word “false” for the more slippery “look different from the truth,” changing “concealing” to “veiling,” and other edits that seek to tone down the rhetoric that inflamed Church leaders. The wording and handwriting corresponds to similar writing by Galileo at the time. Based on this finding, it seems that Galileo did seek to make his ideas more palatable to the Catholic Church in the hopes of escaping persecution by the Inquisition.

Discovered on a research trip by science historian Salvatore Ricciardo of Italy's University of Bergamo, the letter may have been overlooked in the Royal Society archives because it was cataloged as being dated October 21, 1613 rather than the date it actually bears, December 21, 1613. However, it’s unclear how it came to the Royal Society in the first place. The document is the subject of a forthcoming article by Ricciardo and his colleagues in the Royal Society journal Notes and Records, according to Nature.

The minor changes Galileo made did not successfully hold off the Church’s crackdown on heliocentrism. In 1616, the Inquisition ordered Galileo to stop teaching or defending the theory, and several of his books were subsequently banned. He would stand trial again almost two decades later, in 1633, on suspicion of holding heretical thoughts. He was found guilty and sentenced to house arrest, where he remained until his death in 1642.

[h/t Ars Technica]

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