29 ms·

M 7.1 SoCal Earthquake: What's Next?

129 points by mgsouth 7y ago

deleted 7y ago
[deleted]
ianai 7y ago
The scale of geological time never ceases to impress: “There was plenty of accumulated stress, enough to permit a quake with 3 m (10 ft) of slip. That suggests that one can, indeed, have aftershocks 150 years after very large mainshocks”
- mc32 7y ago
  What I don’t get is how is a quake which happens on a disconnected and different fault (heretofore unknown) an aftershock of a previous quake (which occurred over 100 years ago)? I looks like quakes are on a continuum. The extremes are, each quake is an individual event; on the other all quakes are a result and continuation of previous quakes. It seems like the slider position on the continuum is up to a bit of “interpretation”.
  - hvs 7y ago
    As a person that knows nothing about this subject, that's the impression I got as well. The tectonic plates are constantly moving, so of course earthquakes in one place will often cause stress in another place. Understanding this process is certainly important, though.
    - ianai 7y ago
      I think it’s closer to being a constant chain of reactions than otherwise - because the earth has so much heat and magma below its crust.
  - Retric 7y ago
    While plants are moving over 1cm per year that’s not all across a single fault. If you look at a map of them California has an extensive fault network which means it takes far longer than 100 years for a single fault to build up 3m worth of stress. Thus, you can have multiple points of stress all linked where it’s not obvious which one is going to slip first, but they are likely to cluster over relatively short periods. Where 100 years can still be considered short.
wanderfowl 7y ago
The writing and research following this quake series has again underscored for me both a) how little we actually know about predicting earthquakes b) and how frustrating that is. You can read every article out there about the things, and each one ends with, roughly, shrug. As somebody who derives a sense of control from knowledge, it's extra terrifying to have something with such a huge potential impact on me completely in the dark.
- adanto6840 7y ago
  Right there with you. My wife keeps asking me questions about it and she seems dumbfounded that my relaying of information via research generally ends with "we just don't know how it works". It seems to me like we've recently (~15-30yrs) had a lot of new technology deployments (and accessibility to the underlying data that's produced) which might considerably help us with gaining an understanding over time. Things like high-resolution, high-precision aerial & satellite radar/lidar/photography and the like. I tend to think it's just a function of time at this point, but on geological time scales that may still take quite a while I suppose.
  - mgsouth 7y ago
    I'm not optimistic. 1. Hold your hands together, palms open, as if you were praying. 2. Press them together very hard, and at the same time try to slide them past one another. 3. Predict exactly when they will slip, by how much, and how loud the sound will be. To be roughly to scale, it must be with millisecond [0] and millimeter [1] accuracy. [0] Assuming avg. 100 years between quakes, prediction accurate to a week, avg. 5 seconds before hands slip, then 100 yrs * 52 weeks : 1 week ~ 5,000:1 ~ 5 sec : 1 msec. [1] A 150 KM fault with a prediction of slip accurate to 0.5 M movement is 300,000:1. For a hand span of 150 mm that would equate to 0.5 um. On the other hand (pun intended), we could compare maximum slippages; assuming an earthquake movement max of 20 M and a hand slippage max of 0.2 M, a real-world resolution of 0.5 M would equate to a hand-slip prediction accurate to 2 mm.
- lotsofpulp 7y ago
  I don't see the point worrying about things outside of your control. Solar storms, nuclear war, infectious diseases, asteroids, any number of other unknown natural phenomena we know nothing about. Mitigate what you can, try to help others, but accept that at the end of the day, you (and the rest of humanity) are most likely inconsequential in the story of the universe.
needle0 7y ago
One thing I noticed is that when the US talks about earthquakes, it often only notes the seismic magnitude value of the quake and doesn't always mention the seismic intensity scale values of the affected locations. This is in contrast to Japan where quakes are almost always mentioned in both magnitude and the Japan Meteorological Agency's "shindo" intensity scale [1], eg. "The 2011 Tohoku Earthquake was a M9.0 quake with a maximum intensity of shindo 7." The US does have the equivalent of the JMA shindo scale - the Modified Mercalli (MM) scale [2], and they do seem to be used, but I see the MM values mentioned much less frequently than how both the Japanese agencies and the general public refers to shindo values. While the magnitude value signifies the overall energy of the quake, intensity scale values indicate the shaking intensity of a given location; hence, it feels more grounded in one's daily life experiences. Many Japanese individuals have developed an approximate sense of how strong a quake is - conversations like "That was a bit big, somewhere around shindo 4?" are common after quakes. People do of course care about magnitude, but the thing they care most about after a big quake is more likely "what was the seismic intensity in the worst-hit area?" Any idea why intensity scales seem to be much less common in the US? [1] https://en.wikipedia.org/wiki/Japan_Meteorological_Agency_seismic_intensity_scale https://en.wikipedia.org/wiki/Japan_Meteorological_Agency_se... [2] https://en.wikipedia.org/wiki/Modified_Mercalli_intensity_scale https://en.wikipedia.org/wiki/Modified_Mercalli_intensity_sc...
- bribroder 7y ago
  It might be a data collection problem--the JMA has deployed a pretty dense network of sensors over their entire territory, which makes sense given how geologically active it is. In fact the Earthquake Early Warning's "next steps" plan says "New sensors need to be added in California to shorten the CISN sensors spacing to approximately 12 miles to facilitate timely EEW. The shorter the station spacing, the smaller the blind zone will be because warnings can be issued faster." Check out this map comparison of the two networks: https://earthquake.usgs.gov/research/earlywarning/images/stationdensity.JPG https://earthquake.usgs.gov/research/earlywarning/images/sta... https://earthquake.usgs.gov/research/earlywarning/nextsteps.php https://earthquake.usgs.gov/research/earlywarning/nextsteps....
- abcanthur 7y ago
phy6 7y ago
If you can don your anti-quackery bio hazard suit, the youtube channel Dutchsinse is entertaining for his forecast of earthquake locations. His guesses involve following trends along tectonic boundaries on a globe scale. One of the things I've heard him say that I've not heard elsewhere is the implied correlation between geothermal pumping operations near the latest epicenter and crust weakness. https://www.youtube.com/watch?v=Oj6Vj4TOtx4 https://www.youtube.com/watch?v=Oj6Vj4TOtx4
- thanatos_dem 7y ago
  Eek. The content is interesting, but the channel’s style and sound effects are just too much for me. Same problem I have with “Mad Money”.
  - phy6 7y ago
    I agree, too much VHS-iness.
- dane-pgp 7y ago
  What I found interesting about his work is the hypothesis that earthquakes are predictable based on recent nearby earthquakes. This feels like something a machine learning algorithm would have little trouble building a model of, so I'd be interested to know what sort of results people have achieved if this has been attempted before.
caymanjim 7y ago
I can't speak to the merits of this article, but the tone is a bit sensationalist, especially the conclusion, and then they link to some commercial entities to help you prepare for doom. It makes me dismiss the entire article as a fear-mongering advertisement.
olivermarks 7y ago
'...nothing at the ground surface had given this fault away before it fired off the quake. Some of the world’s best field geologists had scoured this area for the past 50 years...'
peter303 7y ago
Interesting a non-peer-reviewed study is released quickly on web. However Dr Stein is one of my Stanford classmates and computing earthquake stress changes for 30 years. So I would believe this study.
coss 7y ago
I live in SoCal and can't believe the amount of attention this has gotten, literally world wide. Am I underestimating the importance or is it just a slow news cycle?
lorrieb2226 7y ago
I live in Corona California and an avid follower of Dutchsinse and his earthquake webcasts. I have the utmost respect for Dutch and for the support he provides on a daily basis 24/7 if he needs to. I as well as hundreds to thousands of people participate daily to be more attentive to events seismically and be prepared not scared. He has been attacked personally and ridiculed being labeled a fear monger! The information is utilized by data researching provided by the professional agencies. Dutch has our backs and provides me the knowledge to feel my safety and my family atleast have a chance of survival and what to look for. I am ashamed to say that my 57 years in california none of the agencies do anything for my safety concerns and I and many like myself feel the same way I trust Dutch and his crucial updates 1000% before considering what my officials status news conferences, broken earthquake alert app malfunctions(available Los Angeles residents only). 7.1 earthquake and Usgs site crashed and unavailable. I reside in Riverside county where shake app is not available. As far as fear-monger tactics Dutch is dedicated to what he does and is extremely gifted with having high school diploma. If you don't like what is being told to you and events surrounding you then go about your way and don't judge someone until you check it out and see his wonderful webcasts and how much he helps anybody who wants to see the truth of earth events. So Blessed to have found Michael Janitch aka DUTCHSINSE.
lorrieblomgren 7y ago
I live in Corona California and an avid follower of Dutchsinse and his earthquake webcasts. I have the utmost respect for Dutch and for the support he provides on a daily basis 24/7 if he needs to. I as well as hundreds to thousands of people participate daily to be more attentive to events seismically and be prepared not scared. He has been attacked personally and ridiculed being labeled a fear monger! The information is utilized by data researching provided by the professional agencies. Dutch has our backs and provides me the knowledge to feel my safety and my family atleast have a chance of survival and what to look for. I am ashamed to say that my 57 years in california none of the agencies do anything for my safety concerns and I and many like myself feel the same way I trust Dutch and his crucial updates 1000% before considering what my officials status news conferences, broken earthquake alert app malfunctions(available Los Angeles residents only). 7.1 earthquake and Usgs site crashed and unavailable. I reside in Riverside county where shake app is not available. As far as fear-monger tactics Dutch is dedicated to what he does and is extremely gifted with having high school diploma. If you don't like what is being told to you and events surrounding you then go about your way and don't judge someone until you check it out and see his wonderful webcasts and how much he helps anybody who wants to see the truth of earth events. So Blessed to have found Michael Janitch aka DUTCHSINSE.

129 points by mgsouth 7y ago

deleted 7y ago

[deleted]

The scale of geological time never ceases to impress: “There was plenty of accumulated stress, enough to permit a quake with 3 m (10 ft) of slip. That suggests that one can, indeed, have aftershocks 150 years after very large mainshocks”

mc32 7y ago
What I don’t get is how is a quake which happens on a disconnected and different fault (heretofore unknown) an aftershock of a previous quake (which occurred over 100 years ago)? I looks like quakes are on a continuum. The extremes are, each quake is an individual event; on the other all quakes are a result and continuation of previous quakes. It seems like the slider position on the continuum is up to a bit of “interpretation”.
- hvs 7y ago
  As a person that knows nothing about this subject, that's the impression I got as well. The tectonic plates are constantly moving, so of course earthquakes in one place will often cause stress in another place. Understanding this process is certainly important, though.
  - ianai 7y ago
    I think it’s closer to being a constant chain of reactions than otherwise - because the earth has so much heat and magma below its crust.
- Retric 7y ago
  While plants are moving over 1cm per year that’s not all across a single fault. If you look at a map of them California has an extensive fault network which means it takes far longer than 100 years for a single fault to build up 3m worth of stress. Thus, you can have multiple points of stress all linked where it’s not obvious which one is going to slip first, but they are likely to cluster over relatively short periods. Where 100 years can still be considered short.

wanderfowl 7y ago

The writing and research following this quake series has again underscored for me both a) how little we actually know about predicting earthquakes b) and how frustrating that is. You can read every article out there about the things, and each one ends with, roughly, shrug. As somebody who derives a sense of control from knowledge, it's extra terrifying to have something with such a huge potential impact on me completely in the dark.

adanto6840 7y ago
Right there with you. My wife keeps asking me questions about it and she seems dumbfounded that my relaying of information via research generally ends with "we just don't know how it works". It seems to me like we've recently (~15-30yrs) had a lot of new technology deployments (and accessibility to the underlying data that's produced) which might considerably help us with gaining an understanding over time. Things like high-resolution, high-precision aerial & satellite radar/lidar/photography and the like. I tend to think it's just a function of time at this point, but on geological time scales that may still take quite a while I suppose.
- mgsouth 7y ago
  I'm not optimistic. 1. Hold your hands together, palms open, as if you were praying. 2. Press them together very hard, and at the same time try to slide them past one another. 3. Predict exactly when they will slip, by how much, and how loud the sound will be. To be roughly to scale, it must be with millisecond [0] and millimeter [1] accuracy. [0] Assuming avg. 100 years between quakes, prediction accurate to a week, avg. 5 seconds before hands slip, then 100 yrs * 52 weeks : 1 week ~ 5,000:1 ~ 5 sec : 1 msec. [1] A 150 KM fault with a prediction of slip accurate to 0.5 M movement is 300,000:1. For a hand span of 150 mm that would equate to 0.5 um. On the other hand (pun intended), we could compare maximum slippages; assuming an earthquake movement max of 20 M and a hand slippage max of 0.2 M, a real-world resolution of 0.5 M would equate to a hand-slip prediction accurate to 2 mm.
lotsofpulp 7y ago
I don't see the point worrying about things outside of your control. Solar storms, nuclear war, infectious diseases, asteroids, any number of other unknown natural phenomena we know nothing about. Mitigate what you can, try to help others, but accept that at the end of the day, you (and the rest of humanity) are most likely inconsequential in the story of the universe.

needle0 7y ago

One thing I noticed is that when the US talks about earthquakes, it often only notes the seismic magnitude value of the quake and doesn't always mention the seismic intensity scale values of the affected locations. This is in contrast to Japan where quakes are almost always mentioned in both magnitude and the Japan Meteorological Agency's "shindo" intensity scale [1], eg. "The 2011 Tohoku Earthquake was a M9.0 quake with a maximum intensity of shindo 7." The US does have the equivalent of the JMA shindo scale - the Modified Mercalli (MM) scale [2], and they do seem to be used, but I see the MM values mentioned much less frequently than how both the Japanese agencies and the general public refers to shindo values. While the magnitude value signifies the overall energy of the quake, intensity scale values indicate the shaking intensity of a given location; hence, it feels more grounded in one's daily life experiences. Many Japanese individuals have developed an approximate sense of how strong a quake is - conversations like "That was a bit big, somewhere around shindo 4?" are common after quakes. People do of course care about magnitude, but the thing they care most about after a big quake is more likely "what was the seismic intensity in the worst-hit area?" Any idea why intensity scales seem to be much less common in the US? [1] https://en.wikipedia.org/wiki/Japan_Meteorological_Agency_seismic_intensity_scale https://en.wikipedia.org/wiki/Japan_Meteorological_Agency_se... [2] https://en.wikipedia.org/wiki/Modified_Mercalli_intensity_scale https://en.wikipedia.org/wiki/Modified_Mercalli_intensity_sc...

bribroder 7y ago
It might be a data collection problem--the JMA has deployed a pretty dense network of sensors over their entire territory, which makes sense given how geologically active it is. In fact the Earthquake Early Warning's "next steps" plan says "New sensors need to be added in California to shorten the CISN sensors spacing to approximately 12 miles to facilitate timely EEW. The shorter the station spacing, the smaller the blind zone will be because warnings can be issued faster." Check out this map comparison of the two networks: https://earthquake.usgs.gov/research/earlywarning/images/stationdensity.JPG https://earthquake.usgs.gov/research/earlywarning/images/sta... https://earthquake.usgs.gov/research/earlywarning/nextsteps.php https://earthquake.usgs.gov/research/earlywarning/nextsteps....
abcanthur 7y ago

phy6 7y ago

If you can don your anti-quackery bio hazard suit, the youtube channel Dutchsinse is entertaining for his forecast of earthquake locations. His guesses involve following trends along tectonic boundaries on a globe scale. One of the things I've heard him say that I've not heard elsewhere is the implied correlation between geothermal pumping operations near the latest epicenter and crust weakness. https://www.youtube.com/watch?v=Oj6Vj4TOtx4 https://www.youtube.com/watch?v=Oj6Vj4TOtx4

thanatos_dem 7y ago
Eek. The content is interesting, but the channel’s style and sound effects are just too much for me. Same problem I have with “Mad Money”.
- phy6 7y ago
  I agree, too much VHS-iness.
dane-pgp 7y ago
What I found interesting about his work is the hypothesis that earthquakes are predictable based on recent nearby earthquakes. This feels like something a machine learning algorithm would have little trouble building a model of, so I'd be interested to know what sort of results people have achieved if this has been attempted before.

caymanjim 7y ago

I can't speak to the merits of this article, but the tone is a bit sensationalist, especially the conclusion, and then they link to some commercial entities to help you prepare for doom. It makes me dismiss the entire article as a fear-mongering advertisement.

olivermarks 7y ago

'...nothing at the ground surface had given this fault away before it fired off the quake. Some of the world’s best field geologists had scoured this area for the past 50 years...'

peter303 7y ago

Interesting a non-peer-reviewed study is released quickly on web. However Dr Stein is one of my Stanford classmates and computing earthquake stress changes for 30 years. So I would believe this study.

coss 7y ago

I live in SoCal and can't believe the amount of attention this has gotten, literally world wide. Am I underestimating the importance or is it just a slow news cycle?

lorrieb2226 7y ago

I live in Corona California and an avid follower of Dutchsinse and his earthquake webcasts. I have the utmost respect for Dutch and for the support he provides on a daily basis 24/7 if he needs to. I as well as hundreds to thousands of people participate daily to be more attentive to events seismically and be prepared not scared. He has been attacked personally and ridiculed being labeled a fear monger! The information is utilized by data researching provided by the professional agencies. Dutch has our backs and provides me the knowledge to feel my safety and my family atleast have a chance of survival and what to look for. I am ashamed to say that my 57 years in california none of the agencies do anything for my safety concerns and I and many like myself feel the same way I trust Dutch and his crucial updates 1000% before considering what my officials status news conferences, broken earthquake alert app malfunctions(available Los Angeles residents only). 7.1 earthquake and Usgs site crashed and unavailable. I reside in Riverside county where shake app is not available. As far as fear-monger tactics Dutch is dedicated to what he does and is extremely gifted with having high school diploma. If you don't like what is being told to you and events surrounding you then go about your way and don't judge someone until you check it out and see his wonderful webcasts and how much he helps anybody who wants to see the truth of earth events. So Blessed to have found Michael Janitch aka DUTCHSINSE.

lorrieblomgren 7y ago