Could a Change in the Earth’s Spin Lead to More Earthquakes Next Year?

By Erik Klemetti | November 19, 2017 7:15 pm
Damage from the November 2017 M7.3 earthquake near the Iran/Iraq border. Farzad Menati / Wikimedia Commons

Damage from the November 2017 M7.3 earthquake near the Iran/Iraq border. Farzad Menati / Wikimedia Commons

If you’ve seen the news over the weekend, you might have seen a bevy of article proclaiming that 2018 will see a big surge in M7+ earthquakes. My first reaction was “ugh” and the next was “sigh”. I thought that yet again the media was being duped by crackpots trying to sell some snake oil prediction scheme.

However, that first pass may have been misguided, but old habits die hard. Instead, this dramatic statement came from a paper in Geophysical Research Letters and an abstract from the Geological Society of America meeting in Seattle. Roger Bilham (Colorado) and Rebecca Bendick (Montana) presented a model that predicts that 2018 will be the opening of a window of potentially higher large earthquake activity due to very, very slight changes in the rate that the Earth spins.

Although we never notice it, the Earth’s spin does change ever so slightly. Geologists aren’t sure what drives this slight variation, but it is likely linked to the Earth’s core. The outer core is a layer of molten iron and nickel that is 2,200 kilometers thick and the whole thing is convecting (moving). This is what drives the dynamo that generates the Earth’s magnetic field, so you should remember to send that “thank you” note to the outer core. However, small changes in that convection in the mantle could be reflected in slight changes in the rate the Earth spins as well.

Just like you might feel that seatbelt pull you in if you hit the brakes (thank you, momentum), if the Earth’s spin slows even a little bit, there is a lot of rock with a lot of momentum that slows with it. You can think of it like the whole planet “sloshing” a little bit. That causes a lot of stress to rocks … and stress added to rocks can lead to earthquakes.

However, Bilham and Bendick say that they have found examples where the slight deceleration of the Earth’s spin take awhile to propagate through the Earth’s rocks. So, after that small slowing of the Earth’s spin happens, there is a 5-6 year lag before they identify an increase of up to 30% in big earthquakes (over magnitude 7) between 10-30º latitude N and S. This increase could last up to 5 years, but the duration is unclear based on the current data.

Why 2018? Apparently 2017 is the 6th year since that last deceleration event, so 2018 may see an increase in M7 earthquakes … and that’s the real issue. This is a theory that comes from looking at data since 1900, so although there have been multiple occurrences of this increase after changes in Earth’s spin, 2018 would be the first time that we could predict that we should expect changes. If an increase happens, then Bilham and Bendick are likely onto something. If it doesn’t this doesn’t mean they are wrong, but rather that the situation might be more complicated then their models suggest.

We’ve already seen two M7 earthquakes over the last few weeks: the M7.3 on the Iran/Iraq border on November 12 and the M7.0 in New Caledonia in the west Pacific on November 19. The former saw over 500 deaths, making it the deadliest of the year. The latter may have generated a tsunami in the Pacific Basin (I write this on the evening on the 19th).

Now, M7 earthquakes can happen multiple times per year — 2017 has already had 7 — so, this may or may not be related to the phenomenon detailed by Bilham and Bendick. They tend to be randomly distributed across time, but geologists have noted clusters of large earthquakes occasionally, so they have possibly come across a mechanism to explain these “mega-earthquake clusters”. The last year that the Earth’s spin might have influenced earthquakes was 2010, which saw 23 M7+ earthquakes.

However, the most important aspect might be that we could begin to prepare ourselves for years that could have more large earthquakes. Nothing in Bilham and Bendick’s work tells us exactly when and where these earthquakes might happen. They just say that we might expect more earthquakes (so, no, not prediction). But even knowing that we could expect an increase means we can make sure people are prepared for a disaster with kits, evacuation plans and emergency management resources.

It is a far cry from any real prediction of earthquakes (this is likely a fool’s errand anyway), but if 2018 does see a real increase in M7+ earthquakes, then we may understanding more about how “big picture” processes like earthquakes and volcanoes* might be influenced by changes within the Earth.

* One note of speculation: If earthquakes see an increase after these changes, one could speculate that volcanic eruptions might also feel this stress too. It will be interesting to see what happens with eruptions in 2018 as well.

CATEGORIZED UNDER: Rocky Planet, Science, Science Blogs
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  • beanfeast

    The first link in the article is about income inequality, not about earthquakes.

    • http://www.wired.com/wiredscience/eruptions/ Erik Klemetti

      Fixed.

  • OWilson

    Gravitation from other bodies in the solar system, including the Sun and the Moon, is gradually slightly slowing the Earth’s rotation, and continually causing tidal effects on the Earth’s oceans and interior.

    Unless there is some other slowing and accelerating processes. that I am not aware of beyond that, there should be no unusual crustal movements leading to increased levels or severity of earthquakes?

    • Kurt S

      There are more influences on rotation. Though those influences can be minimal, they are significant enough to put at the very least pico second differences. A big enough earthquake, volcanic eruptions (especially a super volcano), celestial impact, and a discovery from NASA weather! That last one blew me away (pun intended);

      https://www.nasa.gov/centers/goddard/news/topstory/2003/0210rotation.html

      • OWilson

        Thanks for the cite, but I couldn’t get passed NASA’s:

        “From year to year, winds and air pressure patterns change, causing different forces to act on the SOLID Earth” :)

        And the many references to the conservation of angular momentum all deal with affecting rotation by slowing down, (entropy).

        I was more curious about planetary bodies suddenly speeding up, thereby increasing the centrifugal forces that might cause the molten heavy interior to migrate to the surface. :)

  • kapnlogos

    They have the cause and effect mixed up. When an earthquake happens and part of the earth rises or drops, or when magma rises it changes the rotation of the earth, angular momentum being conserved. Think of being on a merry-go-round and taking a step in or out and the speed of the merry-go-round will change. This changing of angular rotation then manifests itself as stress which then can cause addition ‘changes’ or earthquakes.

  • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

    03 December 2017 is a lunar perigee full moon Quadrupole distortion rock and roll!

    Full moon, 03 Dec 3 2017, 15:47 UTC, 357,987 km
    Lunar perigee, 04 Dec 3 2017, 08:42 UTC, 357,492 km

    Lunar apogee is 406,401 km.

    • Geek0id

      And?

  • David Thomson

    I am looking for a major earthquake in the United States Midwest due to the eclipse in August 2017. The eclipse puts a stronger gravitational tug on the large slabs of rock from the busted up ancient ocean in the region. A 1/16 inch displacement of the large slabs causes the displacement of billions of gallons of water, which then continue to slosh around deep underground with the Earth’s daily tides. Eventually, erosion wears cavities under the slabs and the slabs then sink, causing major earthquakes over a year or more. A similar event preceded the 1811 – 1812 New Madrid earthquakes, and the seismometers in the Midwest have been showing an increase in deep hydraulic resonance since the eclipse.

    Also, I have noticed that the recent Iran earthquake and the Costa Rica earthquake occurred at a time when there was a deep vibration coming through the Earth as registered on all the Earth’s seismometers. Keep an eye on the deep vibrations (heavy background noise) as I am confident they will continue to recur during the coming year.

    • Geek0id

      ECLPISES DO NOT WORK THAT WAY. -Morbo, Probably.

  • Stefani Ciccone

    Read Worlds in Collision, by Immanuel Velikovsky. 60 years ago he warned us that the earth would experience great upheaval in the early 21st century. He said it would begin with our planet’s core heating up. The heat would increase the oceans temp, leading to severe and erratic weather, it would increase volcanic activity, sinkholes and quakes. He also said we could expect an increase in large fireballs. All of these things dramatically shot up in 2010 and have been increasing every year since…basically everything is unfolding just as he predicted and at the time he said it would. Mainstream science calls him fringe science and mocks him, but no can deny his predictions are coming to pass. NASA has been aware of Velikovsky’s work, and because of him, they’ve had time to come up with cover stories to explain the changes. Telling us the earth slowing down is causing earthquakes, is just another cover. Make of this what you will. I’m sure most of you will write it off as quackery, and that’s your right, but if everything Velikovsky said is coming to pass, then its safe to assume these big quakes are the final event before all hell breaks loose.

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Rocky Planet

Rocky Planet covers all the geologic events that made and will continue to shape our planet. From volcanoes to earthquakes to gold to oceans to other solar systems, I discuss what is intriguing and illuminating about the rocks beneath our feet and above our heads. Ever wonder what volcanoes are erupting? How tsunamis form and where? What rocks can tell us about ancient environments? How the Earth might change in the future? You'll find these answers and more on Rocky Planet.
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