Early moment detection that marks the start of massive tremor events

In summary, scientists have found that they can predict earthquakes up to 15 seconds in advance, which could make a big difference in warning people. If the work is validated, it would mean that people could potentially be saved from injury or death in a quake.
  • #1
jim mcnamara
Mentor
4,769
3,813
Popular science: https://phys.org/news/2019-05-scientists-early-moment-megaquake.html
https://advances.sciencemag.org/content/5/5/eaav2032
Image courtesy University of Oregon.

244303

27-scientistsfi.jpg


15 seconds into a massive event, there is data to support the concept of a warning of a coming massive event. Data is based on GPS ground-level readings for more than 20 years. The red X marks the moment.
 
  • Like
  • Informative
Likes Dragrath, davenn, 256bits and 3 others
Earth sciences news on Phys.org
  • #2
15 seconds lead time.
How much difference would that make to sound the alarm?
 
  • #3
"15 seconds lead time."
That's back-to-front, 256 ? If this work is validated, it means that you can spot a 'Great Quake' while its still barely a 'temblor'. The difference between a super-cell warning and sirens...
 
  • Like
Likes 256bits
  • #4
256bits said:
15 seconds lead time.
How much difference would that make to sound the alarm?
It can help a lot of things. That's why earthquake early warning systems and phone apps are starting to be used in the SF Bay Area:

https://sanfrancisco.cbslocal.com/tag/earthquake-warning-system/
Some of the features that are in the works when an early warning alert is sent out:

  • BART and other commuter trains are stopped (or slowed as much as possible before the quake hits them)
  • Elevators go to the nearest floor and open their doors
  • Operating rooms are alerted so they can back scalpels and other instruments out of the patient before the hard shaking starts
  • Airplanes on final approach can be told to abort
  • (other creative actions are taken -- to be determined)...
Of course, part of an effective early warning system is to avoid false alarms. So, many detector sites must all indicate that an earthquake over some threshold magnitude is happening, before the alert can be sent out. It's a hard tradeoff between providing more seconds of warning and being absolutely sure that it is a real earthquake (and not just a heavy semi truck rolling past one of the sensors)...
 
Last edited:
  • Like
  • Informative
Likes Dragrath, Astronuc, dRic2 and 4 others
  • #5
256bits said:
15 seconds lead time.
How much difference would that make to sound the alarm?
You are looking at it backwards. It does not say that you get 15 seconds warning, it says you get a warning 15 seconds after the first measureable onset. How much longer it might be to the full quake is not clear since the graph is unfortunately cut off at 30 seconds. It could be less than 15 seconds or it could be more.
 
  • Like
Likes pinball1970, davenn and 256bits
  • #6
Thanks guys
I missed/misinterpreted the "15 seconds INTO the massive event"

As per @berkeman seconds can make a big difference - informative explanation how seconds count.
 
  • Like
Likes Klystron and berkeman
  • #7
Nik_2213 said:
If this work is validated, it means that you can spot a 'Great Quake' while its still barely a 'temblor'.
hmmm, can't quite see how that comment makes sense ??
 
  • #8
phinds said:
You are looking at it backwards. It does not say that you get 15 seconds warning, it says you get a warning 15 seconds after the first measureable onset. How much longer it might be to the full quake is not clear since the graph is unfortunately cut off at 30 seconds. It could be less than 15 seconds or it could be more.

yup

256bits said:
Thanks guys
I missed/misinterpreted the "15 seconds INTO the massive event"

As per @berkeman seconds can make a big difference - informative explanation how seconds count.
no probs,
but 15 sec is irrelevant if you are within 100km (60 miles) of the event as you have already been hit

EDIT
Actually, I will take that back ... as the radio link signals from the GPS sites travel faster than the
seismic waves and even after the delays due to signal processing, there's still a good chance
that you would get 10 - 12 sec of warning D
 
Last edited:
  • #9
davenn said:
hmmm, can't quite see how that comment makes sense ??
Tremor?
 
  • #10
davenn said:
yup

no probs,
but 15 sec is irrelevant if you are within 100km (60 miles) of the event as you have already been hit

EDIT
Actually, I will take that back ... as the radio link signals from the GPS sites travel faster than the
seismic waves and even after the delays due to signal processing, there's still a good chance
that you would get 10 - 12 sec of warningD
I think I could do a lot in 10 seconds in terms of getting to a secure part of a building or getting away from a potential hazard. Also those at risk from tsunami could have 10 extra seconds to think about higher ground.
 
  • Like
Likes Klystron and davenn
  • #12
I‘m not sure how much this particular study will help the earthquake warning systems. If you are close to a magnitude 7 or 9 quake then your actions won’t depend on that difference - you protect yourself as good as you can anyway. If you are far away then the warning systems can use the information from the full event.

These warning systems are very useful. Japan has a very advanced one. It gives you a magnitude estimate and then a countdown until it will hit your location. I‘m not sure what it does if the time is too short to give both.
 
  • #14
Much better than no estimate. If you have 5 seconds you duck under whatever is next to you, if you have 30 seconds you have time to go to a safer place.
 
  • #15
roj2003 said:
The analytical paper is here - https://advances.sciencemag.org/content/5/5/eaav2032
It seems the authors still have uncertainties in available monitoring for off-shore slips but on-shore is 'good'.
So not much use for potential tsunamis in risk areas?
 

1. What is early moment detection?

Early moment detection is a method used by scientists to identify the beginning of massive tremor events, such as earthquakes. It involves measuring the initial amount of energy released by the event and using this information to predict the magnitude and location of the tremor.

2. How does early moment detection work?

Early moment detection uses seismometers, which are instruments that measure ground motion, to record the initial energy release of a tremor event. This data is then analyzed using mathematical algorithms to determine the magnitude and location of the event.

3. Why is early moment detection important?

Early moment detection is important because it allows scientists to quickly assess the severity of a tremor event and provide timely warnings to affected areas. This can help mitigate potential damage and save lives.

4. What types of tremor events can be detected using this method?

Early moment detection can be used to detect a variety of tremor events, including earthquakes, volcanic eruptions, and even man-made explosions. It is most commonly used for earthquakes, as it can provide valuable information for earthquake early warning systems.

5. Are there any limitations to early moment detection?

While early moment detection is a useful tool for identifying the start of massive tremor events, it does have some limitations. It may not be as effective for smaller or more complex events, and it can also be affected by factors such as distance and local geology. Additionally, it is not a foolproof method and may not always accurately predict the magnitude and location of a tremor event.

Similar threads

  • Earth Sciences
Replies
1
Views
3K
Replies
2
Views
1K
Replies
9
Views
1K
Replies
12
Views
1K
Replies
10
Views
2K
Replies
13
Views
2K
  • General Discussion
2
Replies
65
Views
8K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
8
Views
3K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
5
Views
3K
Back
Top