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The Earth's Rotation Is Slowing and Geologists Are Nervous About What That Means for 2018
10 December 2017
Planet earth with fault lines and tectonic plates, computer artwork. (Getty Images)
On November 30, thousands of people on the East Coast got a surprising afternoon jolt when a 4.1 earthquake struck Dover, Delaware. People reported feeling the quake as far north as Connecticut and as far south as Virginia. It was a rare occurrence on that side of the U.S., and it sent the hashtag #earthquake trending for a few hours. But if a couple of geophysicists in Colorado and Montana are correct, we might be talking about #earthquakes a lot more in 2018.
Buckle up--it's going to be a bumpy ride. https://t.co/s82297ZVrD— Second Nexus (@Second Nexus)1513362282.0
<p></p><p><span style="font-weight: 400;">Roger Bilham of the University of Colorado and Rebecca Bendick of the University of Montana </span><a href="http://onlinelibrary.wiley.com/doi/10.1002/2017GL074934/abstract"><span style="font-weight: 400;">published a study in </span><i><span style="font-weight: 400;">Geophysical Research Letters</span></i></a><span style="font-weight: 400;"> in August suggesting that the periodic slowing of the Earth’s rotation coincides with an increase in larger earthquakes. They already knew there was an uptick in earthquakes approximately every 32 years, and in searching for what might cause these cyclical clusters, they found just one major correlation: the Earth’s slowing rotation during the five preceding years. According to atomic clocks, the Earth’s rotation has been slowing in tiny increments — fractions of a millisecond — for more than four years. This means we might be due for an earthquake cluster next year. </span></p><p><div data-conversation-spotlight=""></div></p><p><span style="font-weight: 400;">The Earth’s periodic slowing is typically imperceptible, but Bilham says it could be seen as a </span><a href="https://www.theguardian.com/world/2017/nov/18/2018-set-to-be-year-of-big-earthquakes"><span style="font-weight: 400;">“five-year heads-up on future earthquakes.”</span></a><span style="font-weight: 400;"> And, unfortunately, the earthquakes he predicts for next year may be a lot stronger and more devastating than the one that recently rattled East Coasters. </span></p><p><span style="font-weight: 400;">The cyclical cluster usually includes a bump in earthquakes that measure more than 7.0 on the moment magnitude scale. A regular year sees about 15 to 20 earthquakes of that size or larger. Next year, the researchers say, </span><a href="https://qz.com/1133304/as-earths-rotation-slows-2018-could-see-a-spike-in-large-earthquakes/"><span style="font-weight: 400;">Earth could see 25 to 30 such quakes</span></a><span style="font-weight: 400;">. And those could be less like the tremblor the East Coast felt last week and more like the </span><a href="https://thesocialedgen.wpengine.com/news/iran-iraq-earthquake-video/"><span style="font-weight: 400;">devastating 7.3 magnitude quake</span></a><span style="font-weight: 400;"> that killed 300 Iranians earlier in November.</span></p><p></p><div id="b655d" class="rm-shortcode" data-rm-shortcode-id="FPFTWF1574878476"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="930072673673207809" data-partner="rebelmouse"><div style="margin:1em 0">A Kurdish channel was live on air when Sunday night's earthquake hit the northern border regions of Iraq and Iran… https://t.co/G912PiSTq9</div> — BBC News (World) (@BBC News (World))<a href="https://twitter.com/BBCWorld/statuses/930072673673207809">1510581579.0</a></blockquote></div><p></p><p>So, what’s actually happening beneath the ground?</p><p></p><p><span style="font-weight: 400;">An earthquake happens when energy stored along cracks in the Earth’s crust — faults — is released. That creates seismic vibrations that shake the ground. Since we know where many faults are, scientists can predict generally where earthquakes might occur. When it comes to the connection with the Earth’s rotation, however, things get a bit more complicated. </span></p><p><span style="font-weight: 400;">Some suggest thinking about it like a spinning skirt: when the rotation speeds up, mass moves closer to the equator, and when it slows down, mass moves back out toward the North and South Poles. The idea is that if this slowing happens after a significant amount of potential energy has already built up along fault lines, or, as </span><a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2017/11/21/the-real-science-behind-the-unreal-predictions-of-major-earthquakes-in-2018/?utm_term=.0ebddd58ffae"><span style="font-weight: 400;">Bendick says</span></a><span style="font-weight: 400;">, “if they’re locked and loaded,” the tiny change in the Earth’s rotation could kick earthquakes into gear.</span></p><p><span style="font-weight: 400;">It’s important to remember that this isn’t a foolproof prediction. It’s notoriously difficult to </span><a href="https://qz.com/664138/this-technology-is-designed-to-predict-big-earthquakes-and-save-lives-but-it-cant-get-funding/"><span style="font-weight: 400;">predict earthquakes</span></a><span style="font-weight: 400;">, and this most recent hypothesis hasn’t been tested in a lab. Bilham himself said, </span><a href="http://www.sciencemag.org/news/2017/10/sloshing-earth-s-core-may-spike-major-earthquakes"><span style="font-weight: 400;">“Of course [it] seems sort of crazy.”</span></a></p><p><span style="font-weight: 400;">But even some skeptics are willing to sign on to this prediction. </span></p><p><span style="font-weight: 400;">“It might be nonsense,” </span><a href="http://www.sciencemag.org/news/2017/10/sloshing-earth-s-core-may-spike-major-earthquakes"><span style="font-weight: 400;">said geophysicist Michael Manga</span></a><span style="font-weight: 400;"> of the University of California, Berkeley. “I’ve worked on earthquakes triggered by seasonal variation, melting snow. His correlation is much better than what I’m used to seeing.” </span></p>
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