Earthquakes can systematically trigger other ones on opposite side of Earth

Posted: August 4, 2018 by oldbrew in Earthquakes, research

Ring of Fire earthquake zone [image credit: BBC]

The understanding of the processes may be lacking, but the evidence is there according to researchers.

New research shows that a big earthquake can not only cause other quakes, but large ones, and on the opposite side of the Earth, reports ScienceDaily.

The findings, published today in Scientific Reports, are an important step toward improved short-term earthquake forecasting and risk assessment.

Scientists at Oregon State University looked at 44 years of seismic data and found clear evidence that tremblors of magnitude 6.5 or larger trigger other quakes of magnitude 5.0 or larger.

It had been thought that aftershocks — smaller magnitude quakes that occur in the same region as the initial quake as the surrounding crust adjusts after the fault perturbation — were the only seismic activity an earthquake could lead to.

But the OSU analysis of seismic data from 1973 through 2016 — an analysis that excluded data from aftershock zones — provided the first discernible evidence that in the three days following one large quake, other earthquakes were more likely to occur.

Each test case in the study represented a single three-day window “injected” with a large-magnitude (6.5 or greater) earthquake suspected of inducing other quakes, and accompanying each case was a control group of 5,355 three-day periods that didn’t have the quake injection.

“The test cases showed a clearly detectable increase over background rates,” said the study’s corresponding author, Robert O’Malley, a researcher in the OSU College of Agricultural Sciences. “Earthquakes are part of a cycle of tectonic stress buildup and release. As fault zones near the end of this seismic cycle, tipping points may be reached and triggering can occur.”

The higher the magnitude, the more likely a quake is to trigger another quake. Higher-magnitude quakes, which have been happening with more frequency in recent years, also seem to be triggered more often than lower-magnitude ones.

A tremblor is most likely to induce another quake within 30 degrees of the original quake’s antipode — the point directly opposite it on the other side of the globe.

Continued here.

  1. DUTCHSINSE has been saying this online for years, adding very accurate predictions of size and locations. My series on Geothermal climate forcing dates back to “Motive Force for All Climate Change” at ClimateRealist, May 2009. Also see Dr Arthur Viterito articles at Principia Scientific,

    “Corollation of Seismic Activity and Recent Global Warming”

    Variable mantle fission is the other climate forcing factor.

  2. oldbrew says:

    Can a large earthquake send a seismic signal in both directions round the Earth, meeting somewhere on the other side?

    7 APRIL 2015
    New study explains source of Earth’s mysterious ringing
    By Nanci Bompey

    Scientists have come up with an explanation of why the Earth rings like a bell.

  3. oldbrew says:

    The Earth is quite sensitive to seismicity…

    The seismic signal of Lionel Messi

    Scientists have a seismometer installed close to the Camp Nou stadium [in Barcelona] and it picks up the telltale vibrations every time the crowd celebrates a goal.

    There is a clear spike in the data as fans jump up and down.
    . . .
    Dr Díaz’s broadband seismometer is positioned 500m from the stadium in the institute’s basement.

  4. Bloke down the pub says:

    I suspect that Piers Corbyn would suggest that external factors make earthquakes around the world more likely to be temporally clustered.

  5. Jim says:

    The only comment here should be, what took so long to for this study? They just figured that out? Or so deartment just needed a cash infusion? Wasn’t it in the 1800’s they figured out loud noises could be heard around the word, so, why not effects of l!ocal tumblers.

  6. JB says:

    Well the link is posting a 404 error on me. What I want to know is just what produced the original quake, and how do they know the secondary quake was NOT caused by the same phenomenon?

    That one quake can be the source of cascade quakes seems like the crust is a very fragile system. Think about this–3 days for the ripple effect to take place? If the earth rings “like a bell” (and I have no issue with that), why would it take 3 days to circumnavigate the planet?

    I’m inclined to think there is something else going on here.

    [mod] link fixed, thanks

  7. oldbrew says:

    Indonesia issues tsunami warning after earthquake strikes off Lombok island
    Aug 5, 2018

    A magnitude 7.0 earthquake rocked Indonesia’s popular tourist island of Lombok on Sunday, according to the United States Geological Survey.

    The quake struck at a depth of 10.5 kilometers off the north coast of Lombok, a little over a mile from Loloan village, the USGS said.

    Indonesia’s agency for meteorology, climatology and geophysics issued a tsunami warning just minutes after the earthquake hit.

  8. oldbrew says:

    JB says: ‘why would it take 3 days to circumnavigate the planet?’

    Report: The higher the magnitude, the more likely a quake is to trigger another quake.
    . . .
    “But irrespective of the specific mechanics involved, evidence shows that triggering does take place, followed by a period of quiescence and recharge.”

    It’s a trigger, but not like firing a gun. A chain of causality may occur, where the quake is the end product.

  9. pochas94 says:

    That’s what I think happened at the KT extinction. A meteor struck just off the Yucatan peninsula (The Chicxulub crater). The shock waves then resulted in the sea floor rupturing at the antipode and subsequent volcanism produced the Indian subcontinent, which rose above sea level and has since migrated across the equator to its present position collided with Eurasia. The meteor strike plus the volcanism produced the KT extinction.

  10. Curious George says:

    I injected an earthquake into data, and I also injected a response earthquake a day later into the data. Result: the response earthquake always followed the original injected quake in a day. Long live science, and Oregon State University.

  11. angech says:

    Contra coup, a medical term for damage in the brain to be found on the other side of the head to where it was hit. Seems a similar analogy.

  12. oldbrew says:

    Survey of anomalous Schumann resonance phenomena observed in Japan, in possible association with earthquakes in Taiwan [2016]

    The paper discloses the causative link between the anomalous Schumann resonances and earthquakes in Taiwan. Especially, the land earthquakes with large magnitude are found to trigger the anomalous Schumann resonances.
    – – –
    The Schumann resonances (SR) are a set of spectrum peaks in the extremely low frequency (ELF) portion of the Earth’s electromagnetic field spectrum. Schumann resonances are global electromagnetic resonances, generated and excited by lightning discharges in the cavity formed by the Earth’s surface and the ionosphere.

  13. Anthony says:

    See where such predictions are with coordinates

  14. Anthony says:

    See also where epicenter coordinates are predicted.

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