mturmon 16 hours ago | parent | next [-]

I think you intended this to be a validation of the idea that small quakes relieve stress and therefore lower the chance of a large quake.

The above link does not answer that question. It is relating stress release to "fault strength", or the maximum shear stress that can be withstood by the fault. There is an incidental relationship with depth that plays a role.

The video linked nearby (on criticality) also does not address the question at issue.

I'm only replying because I work adjacent to this area, and my understanding is that the idea that small EQ's release stress is a myth. Here [1] is another link, listed as #1 in the "Myths" category. And you can dig up quotes from none other than Lucy Jones [2] saying that this is a myth.

I don't work directly in this area, so I'm not willing to say absolutely no. But I'd really like to see a head-on reference supporting the claim that it's not a myth.

[1] https://earthquakes.berkeley.edu/outreach/faq.html

[2] https://en.wikipedia.org/wiki/Lucy_Jones

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fc417fc802 14 hours ago | parent [-]

EQs are a release of energy. That energy is stored as stress prior to release. There is a finite amount of stored energy at any given time.

So the statement "EQs release stress" is true and it follows that adding the modifier "small" to the front doesn't change this.

It should also be immediately apparent that it would be very surprising if there were not statistical implications as a result of this. So surprising in fact that I would suggest that the burden of evidence should fall on those claiming that any such statistical effects are unexpected.

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mitthrowaway2 9 hours ago | parent [-]

This part is unquestionably true. But since we don't have a direct measurement of the stored energy at a given time, the occurrence of an earthquake acts as both an indicator of release of stored energy but also, potentially, evidence of increasing stored energy.

Like how buying a Porsche costs money, and leaves you poorer than before you bought it, but when you see stranger buy a Porsche, you update towards believing that they're wealthy rather than poor.

Disclaimer: I am not a geoscientist.

	▲	fc417fc802 6 hours ago \| parent [-]
		Fair enough. I'm also not a geoscientist, and to clarify I didn't mean to imply any specific statistical effect there. It seems entirely reasonable to me that a series of EQs might tend to increase in intensity. In reality I think (layman's impression) that there's rough (post hoc) evidence for both things. Foreshocks followed by noticably larger EQs as well as trains of progressively smaller EQs.

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criddell 18 hours ago | parent | prev [-]

https://news.caloes.ca.gov/earthquake-myths-separating-fact-...

Myth 5 is "Small Earthquakes Relieve Pressure and Prevent Larger Ones"

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fc417fc802 17 hours ago | parent | next [-]

GP is correct; I'm not sure why CA gov is calling that a myth (it's not). However keep in mind that it's not necessarily true 100% of the time. Or at least the things it might seem to imply at first glance aren't true - the presence or absence of small quakes in a given period doesn't necessarily tell you anything useful about the future.

	▲	jacquesm 16 hours ago \| parent [-]
		Indeed. But I get why people are confused because it is a subtle difference between 'stress relieved through small earthquakes is stress expended' vs 'stress relieved through small earth quakes is not indicative of the magnitude of future events'. The long term absence of stress relief small quakes on a known fault line might be bad news, or no news at all, statistics are where the difference is here, not in particular events. See also, 'the big one' and various theories around it.

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jacquesm 18 hours ago | parent | prev [-]

Myth: new knowledge never trumps old knowledge. Check the dates on those two publications.