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Around the world seismic measurements were quieter during lockdown

Something that marks how strange times are, was that in March and April, a group of seismologists found seismic activity fell by 50% at 185 stations around the world (at least in certain high frequency bands from 4 – 14 Hz). For example the three graphs below show seismic activity in Brussels, Barbados and New Zealand. A slight downturn happens at Christmas but the lockdown period fell far below that.

For the first time seismologists could identify small quake signals they had missed before.

Co-author Dr Stephen Hicks, from Imperial’s Department of Earth Science and Engineering, said: “This quiet period is likely the longest and largest dampening of human-caused seismic noise since we started monitoring the Earth in detail using vast monitoring networks of seismometers.

Who knows what they might figure out now they have a handle on human background “noise”.

Siesmic noise quietened during lockdown.

(B) Lockdown effects in hiFSAN compared with audible environmental noise and independent mobility data in Brussels, Belgium. (C) Lockdown effect in Barbados compared to noise levels in the last decade (in gray) and correlation with local flight data at the Grantley Adams International Airport (TBPB) (24). (D) Lockdown noise reduction recorded on borehole seismometers in Auckland, New Zealand.   (Click to enlarge).

For the record, there will be an array of other frequencies that aren’t listed here because they didn’t change much.

It’s just a bit of Covid trivia, but as an opportunity for experiments, 2020 is surely a researchers dream.

For the technically inclined:

We assessed the effects of COVID-19 lockdowns on high-Frequency (4–14 Hz) Seismic Ambient Noise (hiFSAN; (24)). We compiled a global seismic noise dataset using vertical-component seismic waveform data from 337 broadband and individually operated citizen seismometer stations (24), such as Raspberry Shakes (RS), with a self-noise well below the ground motion generated by anthropogenic noise (25), and flat responses in the target frequency band (Fig. 1). For 268 seismic stations, we obtained usable data (e.g., no large data gaps, working sensors) and found significant reductions in hiFSAN during local lockdown measures at 185 stations (Fig. 2). Periods that are often seismically quiet include weekends, and the Christmas / New Year holidays for those locations where these are celebrated. We found a near-global reduction in noise, commencing in China in late Jan 2020, then followed by Europe and the rest of the world in Mar to Apr 2020. The noise level we observe during lockdowns lasted longer and was often quieter than the Christmas to New Year period.

 

REFERENCE

T. Lecocq et al.(2020). Global quieting of high-frequency seismic noise due to COVID-19 pandemic lockdown measures,, Science, 10.1126/science.abd2438

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Rating: 9.7/10 (36 votes cast)
Around the world seismic measurements were quieter during lockdown, 9.7 out of 10 based on 36 ratings

77 comments to Around the world seismic measurements were quieter during lockdown

  • #
    Geoffrey Williams

    This missing seismic activity, could it be the low level rumble of human activity and industry.
    Eg Mining, manufacturing and transport etc . .
    GeoffW

    60

    • #
      Graham Richards

      Nah, the seismic movement, unlike protesters, were simply obeying the lockdown rules!

      20

    • #
      AndyG55

      I wonder what level of seismic activity those huge herds of buffalo that once roamed the USA would have registered !

      Or a herd of brontosaurus .

      60

    • #
      sophocles

      How strange, the sun was pretty quiet too, as it got itself organized to get SSC 25 fully under way.

      Given how involved our local star is with The Third Rock From the Sun’s seismicity. the lesser intensity might not be so coincidental nor of human origin. Not everything is humanity’s fault, there are other players involved, one of which is just a bit more powerful than mankind.

      See https://quakewatch.net for more info …

      30

      • #
        sophocles

        The biggest muffling would be lack of semi-trailers esp. on the motorways through and around the city environs. ‘
        Multiple axles thumping over road/bridge expansion joints would fit the 4-14 Hz band …

        10

  • #
    Kalm Keith

    Has the potential to be a bit like the Global Temperature data in the number of input factors.

    Heavy rail passenger transport would have been substantially reduced so the area around Sydney central would have gone quiet but maybe Katoomba would barely notice the change.

    An interesting topic but I don’t think that Nancy’s stamping her foot and screaming for even more attention would register: massive Boeing 747 on takeoff would send a lot more energy into the ground.

    80

  • #
    Doubting Dave

    Is it April the 1st, coralation is not causation but you all knew already, it’s been a while but hope your all well

    60

  • #
    tom0mason

    I think I’d prefer lots of micro rumblings reliving some of the seismic stresses, than sudden and devastating major earthquakes.

    70

  • #
    Jojodogfacedboy

    If you have had the experience of playing with holographic photography…
    It takes having your table to be totally floating by mechanical means as the ground vibrations blurr the lasers 3 dimensional image on the photography film.
    Real cool stuff to see the lasers split and different lenses to focus the beams into a re-creation.
    The person did a fantastic holographic film with a human heart with blue and red valves onto a piece of film.
    These older lasers took a lot more power than today’s lasers.

    40

  • #
    David Maddison

    Victoriastan, under one of the most totalitarian extreme C-19 lockdowns in the world would be an ideal place to do some measurements, if the seismologists were allowed out of home to attend their place of work or equipment location (I’m not sure if they need to access their equipment to make measurements or adjustments or not or if remote control is possible).

    61

    • #
      Annie

      We live about two hours’ drive out of Melbourne but even now I am aware of an underlying rumble at night. I see from news reports on the box that trams are still running somewhat; they can rumble (we used to live right by a busy tramline in Melbourne).

      31

  • #
    David Maddison

    We had and still have a “climate change” establishment who are promoters of the anthropogenic global warming lies.

    I think we now also have a C-19 establishment who are responsible for both withholding potentially beneficial low risk treatments and for implementation of maximum economic destruction.

    Economic destruction of the West was the ultimate objective of the lie of anthropogenic global warming but it has been discovered to be much more efficient with C-19 than AGW ever was. The money wasted and economic damage of AGW looks like a minor hiccup compared to C-19.

    101

    • #
      Kalm Keith

      A hundred years of work, thrift, building and developing washed away in the last few decades by Politicians.

      110

      • #
        sophocles

        They [politicians] are not well enough schooled to be able to sort propaganda from facts — that’s why they’re in politics because it’s the only place left to earn well with their educational `handicaps.’

        20

  • #
    EternalOptimist

    I heard that a lot of seismic readings are not seismic readings. They are people phoning into the seismic reading measurement station saying ‘dust fell off my shelf’

    50

  • #
    David Maddison

    You can check out the latest Australian earthquakes at the following site:

    https://earthquakes.ga.gov.au/

    I assume earthquakes aren’t currently being “homogenised”.

    31

  • #
    PeterS

    Global cooling?

    10

  • #
    Peter Fitzroy

    Anthropogenic seismic activity (ASA) demonstrates just how much of an effect humans have on this world. If you can accept this, then in time, you’ll be able to accept AGW.

    /as the Whitehouse says ‘don’t let science get in the way..’

    216

    • #
      Kalm Keith

      Prooof of data trooof.

      Hilarious. :-) :-) :-) :-) :-)

      70

    • #
      robert rosicka

      You really are brainwashed Peter , I feel sorry for you and those blinkers you have on .

      100

    • #
      AndyG55

      “‘don’t let science get in the way..’”

      Yet you ALWAYS DO. !

      Do you have even the slightest empirical evidence for warming by atmospheric CO2?

      NO, YOU DON’T

      You have NO SCIENCE…. just rancid brain-hosed “belief”

      140

    • #
      AndyG55

      Measurements show we create minor seismic activity, and that when human activity is constrained, we create less than usual.. just as anyone would expect.

      SO WHAT !

      Its not “earthquakes” is just essentially white noise.

      Its basic engineering…. so, well outside anything you would understand.

      110

    • #
      AndyG55

      And of course, there is absolutely no evidence that human white noise seismic activity is causing any harm to anything….

      Just like there is absolutely no evidence human CO2 is causing any harm to anything, and is IN FACT, proven to be wholly BENEFICIAL to existence of life on the planet.

      110

      • #
        sophocles

        … just as there is no proof galloping bison, elephants, rhinos, horses, antelope by the herd etc, all of which can be heard through the ground for quite surprising distances, are doing any damage either.

        Peter would be surprised at just how much noise can be and is transmitted through the ground so why worry about mankind’s contributions? He could put an ear down and listen for echoes of WW2 …

        20

    • #
      Strop

      Ah, so it’s the earth vibrating / plate friction that’s causing the warming. Not CO2. Well done Peter. You’ve just saved the fossil fuel industry.

      100

    • #
      David Maddison

      Peter Fitzroy, today we have extremely sensitive measuring equipment and we can even measure dimensional changes due to gravity waves of the order of 10^-18 of a meter which is about a million times less than the size of an atom.

      Just because something is measurable, including anthropogenic influence, doesn’t mean it’s significant or a problem.

      91

      • #
        Peter Fitzroy

        I’m saying that man is having a measurable effect on the world, highlighted by the seismic activity on the post. The impact of that effect is a different argument

        04

        • #
          AndyG55

          Oh course man has a measurable affect, basically all movement does.

          You can measure the sound from a click of the fingers, or from a bees wings buzzing if you have right gear..

          or maybe even the flap of a butterflies wings ;-)

          Its you idiotic attempt to link this to CO2 caused climate change, which has NEVER been observed or measured anywhere on the planet…

          That is what is so RIDICULOUS about your original post.

          40

          • #
            sophocles

            I had a friend who worked for ANAC back when it was alive. (1980s?) They built very sensitive tilt-meters.

            They had to be taken well outside the city to calibrate them – on Sundays because they were the quietest days of the week – the urban background noise was just a little overwhelming and Auckland back then was a lot smaller than it is now.

            00

        • #
          AndyG55

          “The impact of that effect is a different argument”

          The impact of urban white seismic noise on the actual planet is….??

          ….. NADA, nothing, insignificant, immaterial. !

          If you think it does have a global effect, provide evidence, not just “make-it-up” fantasy.

          Heck, at least we can measure it with very sensitive equipment…

          … which is more than can be said for any warming effect of atmospheric CO2.

          30

    • #
      David Maddison

      Peter, when a train rolls by, does the earth move for you?

      It does for me.

      71

  • #
    MrGrimNasty

    The eco-fruits funded by Russian cash and supported by their troll/bot disinformation campaign (which strangely the UK gov. ignored in its Russian ‘interference’ report) succeeded in making fracking completely nonviable because the seismic limits were set so low, undetectable by humans in fact, that the site manager dropping his biro forced them to shut down.

    Meanwhile, when they were piling a windfarm about 10km from me out at sea, I had many months of lost sleep and headaches from the constant rhythmic thump which was a bit like being smacked around the head with a heavy rubber mallet. On the worst nights the windows were banging and dust was falling down and things were moving on the shelves. There was also a suspicious number of dead cetaceans turning up on the beach.

    Anyway, hopefully whilst things were quiet they managed to track down any stray Graboids.

    71

  • #
    John F. Hultquist

    Speaking of seismic activity:
    2020-08-09 05:07:37 (UTC-07:00)
    Location 36.476°N 81.093°W – - – 4km SE of Sparta North Carolina
    Depth 3.7 km
    {and 39 others in the last day}
    Clickable map for info – -
    https://earthquake.usgs.gov/earthquakes/map/

    20

  • #
    AndyG55

    The first graph is nice, you can clearly see the weekends.

    Around 20th March was the low point in activity, but week-day activity climbed up to “usual”, within about 6 weeks.

    20

  • #
    Strop

    This could be handy in the future. The next time China goes seismically quiet we know to immediately shut our borders and open quarantine.
    And have all returning citizens diverted to quarantines other than Victoria.

    60

    • #
      PeterS

      I’m sure the US has high resolution satellite imagery that could be used to detect such an event. It would be nice if the US would share such knowledge to the world whenever it occurs to give us advanced warming and allow us to close off all travel to and from China ASAP.

      20

  • #
    beowulf

    China has been having swarms of quakes before and during the floods. There has been volcanic activity at Dawei Mountain south of Wuhan (to the ESE of the Three Gorges Dam) where magma recharge of the “extinct” volcano has been detected. Since the dam lies on 2 fault lines, all this earthquake activity could be problematic, compounding the other issues with the wall. The more notable quakes were four 4.9s in central China during July, followed by a 6.3 shaker closer to Nepal on 22/7, in addition to the numerous small quakes.

    Prior to all the flooding and quakes there was erratic animal behaviour such as fish jumping out of rivers and lakes en masse in 3 provinces over a period of weeks, a known precursor to earthquake activity.

    If you want to talk quakes, Dutchsinse is a go-to site with top notch graphics and up to date technical commentary. He also gives his own predictions of likely activity.
    https://www.youtube.com/c/DutchsinseOriginal/videos

    20

  • #
    Bulldust

    I note the ABC seamlessly switched from case numbers (because they appear to have peaked) to death numbers, because that’s where the maximum fear factor resides:

    https://www.abc.net.au/news/2020-08-10/australia-coronavirus-death-toll-passes-300/12539346

    Never mind that virtually every single death is someone in their 60s-100s, mostly towards the end of that range.

    50

    • #

      Never mind that virtually every single death is someone in their 60s-100s, mostly towards the end of that range.

      virtually. In other words there are people younger than 60. Where are you getting your data?

      note the ABC seamlessly switched from case numbers (because they appear to have peaked) to death numbers, because that’s where the maximum fear factor resides:

      In multiple places they have reported all data (so incorrect again) and noted that deaths was the most in a single day. Why is that a problem? Your comment about maximum fear factor is totally made up and unsupported.

      03

  • #
    John in Oz

    This is most surprising given the amount of foot-stamping and hissy fits going on by the pro-CAGW, anti-Covid and BLM protesters.

    Then there are those of us beating our heads against the wall trying to get more rational thought and science into these topics.

    40

  • #
    Andrew McRae

    Part of this signal reduction has to be from reduced aircraft flights. There is a giant footprint of slightly increased air pressure below any heavier-than-air aircraft in flight. The heavier the aircraft the larger the overpressure. As this pressure wave travels at over 200km/hr it must be like a giant tyre rolling across the land, which I imagine sets off a small seismic vibration too. No idea of the frequency, so maybe it is not in the range shown.
    They’d have to go back to individual station data pre-pandemic and find where a logged flight overflew the seismometer, then find the same hour and day of the week during pandemic when the flight did not occur, get the difference as a non-overflight, and sum all those separate non-overflights. ie The dog that didn’t bark.

    20

    • #

      David and I were wondering what would cause the 4 – 14 Hz frequency last night. I did not consider planes. Only trains and trucks.

      11

    • #
      Kalm Keith

      Hi Andrew, undoubtedly during take off and landing the energy transmitted to ground would be significant but I’m not so sure that during flight there would be anything of significance registering at ground level.

      00

      • #
        sophocles

        What do you think helps wind up tropical cyclones in response to a CME slapping us in the face?

        Hint: pressure waves (and gravity waves).

        10

      • #
        Andrew McRae

        Instruments can be so much more sensitive than human senses that your personal intuition about what is “significant” may not be relevant to the topic. Other graphs I’ve seen suggest to me that any seismic waves from an aeroplane would be much lower frequency than the 4Hz limit in the story above, so I was mistaken about that part.

        But I would not be so quick to discount the whole idea of seismometers detecting passenger aircraft.
        https://www.researchgate.net/publication/281242239_Helicopter_vs_Volcanic_Tremor_Characteristic_Features_of_Seismic_Harmonic_Tremor_on_Volcanoes
        (My bolding)

        We recorded high frequency (> 10 Hz), harmonic tremor with spectral gliding at Hekla volcano in Iceland. Particle motion plots indicated a shallow tremor source. We observed up to two overtones beneath our Nyquist frequency of 50 Hz and could resolve a source of closely spaced pulses of very short duration (0.03-0.1 s) on zoomed seismograms. Volcanic tremor with fundamental frequencies above 5 Hz, frequency gliding and/or repetitive sources similar to our observations were observed on different volcanoes around the world. However this frequency content, duration and occurrence of volcano related tremor was not observed in the last 35 years of seismic observations at Hekla. Detailed analysis reveals that this tremor was related to helicopters passing the volcano. This study relates the GPS track of a helicopter with seismic recordings of the helicopter at various distances. We show the effect the distance, number of rotor blades and velocity of the helicopter has on the observed up and down glidings at up to 40 km distance. We highlight similarities and differences between volcano related and helicopter tremor in order to help avoid misinterpretations.

        A puny little helicopter was detected at a distance of 40km, so a large passenger airliner adding a detectable signal at 10km range is within the realms of the possible.

        This line of reasoning has even been used to argue that a seismometer on Cocos Island may have detected MH370 flying within 6km range of the main airport several hours before it completely disappeared.

        00

        • #
          Annie

          An approaching helicopter makes a really booming ‘chopping’ noise which I can hear while it is still pretty far off. Once it is over here the noise is much less bothersome.

          11

        • #
          Kalm Keith

          Andrew,

          A helicopter is not Puny. It is an extremely inefficient way of flying and having vertical thrust is obviously capable of registering on seismic equipment.

          An airliner in flight has massive horizontal thrust and remains suspended by the vacuum effect on the upper wing surface. Nothing is directed downwards except during take off and landing.

          00

          • #
            Andrew McRae

            KK, I suggest you read about how wings generate lift before venturing any further opinions in this area.
            In their aerodynamics a rotary wing is not fundamentally different than a fixed wing. From the airfoil’s perspective they work the same way; generating a pressure difference by bending airflow. With regards to “nothing is directed downwards”, Mr Newton and Mr Bernoulli have a few wise pieces of advice for you there. Air has to be directed downwards to make the lift reaction force, and it is that “vacuum effect” (as you called it) which does that directing on the top surface.

            It’s because there is no definite limit to how far the high pressure region below the wing can spread out, and the fact you can hear a “whump” when a jetliners’ sound cone first reaches you, that there is every reason for suspecting the elevated pressure region reaches all the way to the ground. None of that establishes whether seismometers can detect it, but we won’t get anywhere by using false wing physics.

            And I would not call helicopters inefficient because nobody has found a more efficient way to do everything a helicopter can do. :-)

            00

            • #
              Kalm Keith

              It’s certainly true that up to 40 miles or so after takeoff you may be able to hear the low murmur of a jet passenger aircraft as it continues to gain altitude, maybe.

              As to the rest of it, unbelievable, but go on, you stick to your guns.

              Bizarre.

              00

    • #
      Strop

      Are flight patterns significantly less around the “normal” seismic quieter periods, such as Christmas and weekends? If not, then maybe flights aren’t a factor.

      I have the impression that Tues/Wed is the quieter flight travel period. But maybe that’s just passengers and not flights. But I’d assume airlines would reduce flights if demand is less.

      00

  • #
    David

    The average life expectancy in Australia is about 83. The average COVID 19 age at death is about 83. So all these shutdowns have achieved nothing!

    63

    • #

      Off topic David.

      Define “nothing”. Should we mark all 83 year olds as “do not resuscitate”, “don’t treat”, “don’t try”? Perhaps ban them from GP’s since we are just prolonging the nothing. Might not be a civilization we want to live in, but would make health care cheaper.

      PS: I’ll probably move these OT things. Can people try to stick to topic ?

      13

    • #
      Kalm Keith

      David, I wouldn’t say they’ve achieved “nothing”.

      The suicides from the human damage caused by the lockdowns will be higher eventually than the the CV19 deaths by a significant amount. In Australia, of course.

      Overseas you might be left wondering if a significant number of deaths from other causes, like flu, have been “mistaken” this year as being from CV19. I’m not sure whether the U.N. or WHO may have financial aid available for CV19 support. Maybe Brazil will get some?

      20

  • #
    David Maddison

    Apologies, off topic.

    Slowly some of the medical profession are waking up.

    Professor Borody says his research has led him to a triple therapy of Ivermectin, zinc and an antibiotic – which are all TGA and FDA approved – which could be the fastest and safest way to stop the Victorian outbreak within 6-8 weeks.

    He said he knows of medical professionals already using it as a preventative therapy themselves.

    https://www.healthindustryhub.com.au/pharmaceutical-news-trends/australian-triple-therapy-for-covid-19-cure-and-prevention/

    61

  • #
    Mal

    Are we picking up the low frequency rumbling from the thousands of wind turbines Now in operation

    50

    • #
      AndyG55

      Would certainly be interesting to do low frequency measures near off-shore wind turbines.

      We know that on-shore wind turbines cause sub-sonic disturbances that can have a severe effect on human anatomy, but no-one seems to care much about the effect the of-shore turbines might have on the larger sea creatures.

      60

      • #
        sophocles

        What was your weather like during your lockdown?

        Anticyclonic? Because here in NZ it was pretty windless.

        Lack of windfarm productivity (on land) could have contributed to lower noise levels.

        10

    • #
      beowulf

      You’re talking micro-seismicity.

      http://notrickszone.com/2017/05/31/new-study-sees-new-health-risk-to-humans-from-wind-turbines-micro-seismicity/

      The study also found that micro-seismic waves impact the measurements of seismological centers that were even 15 km away from a wind turbine.

      The abstract of the study:

      Infrasound, low frequency noise and soil vibrations produced by large wind turbines might disturb the comfort of nearby structures and residents. In addition repowering close to urban areas produces some fears to the nearby residents that the level of disturbance may increase. Due to wind loading, the foundation of a wind turbine interacts with the soil and creates micro-seismic surface waves that propagate for long distances and they are able to influence adversely sensitive measurements conducted by laboratories located far from the excitation point.”

      20

      • #
        Kalm Keith

        An interesting and logical effect that complements the disgusting issue of vlf air pulsing from the blades.

        A hidden and serious effect suffered by truck and train drivers and operators of other vibrating equipment.

        The windmill operators love to confuse the issue and have it examined as “noise” but it is a much uglier problem than that.

        This one issue on its own shows how uncaring and callous the so called “environmental movement” really is: it’s only ever been about the money.

        10

  • #
    David Maddison

    Interesting paper:

    Urban seismology has become an active research field in the recent years, both with seismological objectives, as obtaining better microzonation maps in highly populated areas, and with engineering objectives, as the monitoring of traffic or the surveying of historical buildings. We analyze here the seismic records obtained by a broad-band seismic station installed in the ICTJA-CSIC institute, located near the center of Barcelona city. Although this station was installed to introduce visitors to earth science during science fairs and other dissemination events, the analysis of the data has allowed to infer results of interest for the scientific community. The main results include the evidence that urban seismometers can be used as a easy-to-use, robust monitoring tool for road traffic and subway activity inside the city. Seismic signals generated by different cultural activities, including rock concerts, fireworks or football games, can be detected and discriminated from its seismic properties. Beside the interest to understand the propagation of seismic waves generated by those rather particular sources, those earth shaking records provide a powerful tool to gain visibility in the mass media and hence have the opportunity to present earth sciences to a wider audience.

    https://www.nature.com/articles/s41598-017-15499-y

    00