Is a 10.0 earthquake actually possible?

[ElliotSmith]

Is a 10.0 magnitude earthquake theoretically possible?

The most -powerful quake ever recorded was a 9.5, which occurred just off the coast of Chile on May 22nd, 1960.

 

[phinds]

Is a 10.0 magnitude earthquake theoretically possible?

The most -powerful quake ever recorded was a 9.5, which occurred just off the coast of Chile on May 22nd, 1960.

A Yellowstone supervolcano erruption would likely be bigger that 10.0 although I've never seen any actual estimates of where it would fit on the scale, just that it would dwarf anything in recorded history.

A magnitude 10.0 earthquake is not theoretically possible within the framework of the moment magnitude scale (Mw), which is the modern scale used to measure earthquake magnitudes. The moment magnitude scale is a logarithmic scale, which means that each whole number increase on the scale represents a tenfold increase in the amplitude of seismic waves and approximately 31.6 times more energy release.

 

[berkeman]

The 1964 earthquake was a 9.2, and one of my fellow emergency trainers was in the thick of it. He was a young military police officer at Elmendorf AFB when it happened, and has given a number of emergency response presentations about it. Incredible.

Also paging @davenn to help answer your question...

https://en.wikipedia.org/wiki/1964_Alaska_earthquake

 

[Ygggdrasil]

Thinking historically about the most powerful earthquake causing events on Earth, I found this:

Models suggest the impact at Chicxulub was a million times more energetic than the largest nuclear bomb ever tested. An impact of this size would eject material at high velocity around the world, cause earthquakes of magnitude >10, continental shelf collapse, landslides, gravity flows, mass wasting and tsunamis and produce a relatively thick and complex sequence of deposits close to Chicxulub

source:https://blog.nationalgeographic.org/2010/03/04/asteroid-terminated-dinosaur-era-in-a-matter-of-days/

 

[phinds]

Thinking historically about the most powerful earthquake causing events on Earth, I found this:

source:https://blog.nationalgeographic.org/2010/03/04/asteroid-terminated-dinosaur-era-in-a-matter-of-days/

No argument that it likely had an effect greater than a 10.0 earthquake, but it was NOT an earthquake, which is the subject of this thread.

 

[Ophiolite]

No argument that it likely had an effect greater than a 10.0 earthquake, but it was NOT an earthquake, which is the subject of this thread.

The quoted text from Ygggdrasil states clearly "cause earthquakes of magnitude >10". It may be a matter of semantics, but I don't recall any definition of earthquakes that specifies the energy source. A significant vibration of the lithosphere caused by an energy release is, ipso facto, an earthquake.

 

[phinds]

The quoted text from Ygggdrasil states clearly "cause earthquakes of magnitude >10". It may be a matter of semantics, but I don't recall any definition of earthquakes that specifies the energy source. A significant vibration of the lithosphere caused by an energy release is, ipso facto, an earthquake.

Yes, you make a fair point. I tend to think of earthquakes as something caused by tectonic plates shifting.

 

[Ophiolite]

Yes, you make a fair point. I tend to think of earthquakes as something caused by tectonic plates shifting.

And most of them are, especially the larger ones, but impacts, isostatic adjustment, mass wastage, volcanic activity, etc are also sources. (The current Mars probe, Insight, is designed to measure Marsquakes and proper attention has been given to distinguishing small impact events from "true" quakes.)

 

[davenn]

Is a 10.0 magnitude earthquake theoretically possible?

The most -powerful quake ever recorded was a 9.5, which occurred just off the coast of Chile on May 22nd, 1960.

Also paging @davenn to help answer your question...

cheers

An actual earthquake as in a tectonic earthquake of M10 is relatively unlikely.

No argument that it likely had an effect greater than a 10.0 earthquake, but it was NOT an earthquake, which is the subject of this thread.

Yes, exactly

The issue with tectonic quakes is that there is only so much stress that can build up on a section of fault line
before it will fail. Overcoming the frictional forces on the slip surface is the deciding factor.
The only fault lines that can produce M9 + are the large subduction zone, Megathrusts, namely ...

1) offshore NW USA and Canada ... 1 known
2) offshore southern Alaska and out westward across the Aleutians ... 1 known
3) offshore eastern Kamchatka Penin. and down the eastern side of Japan ... 2 known
4) The Sumatera and Java zones offshore of western Indonesia ... 1 known
5) the trench between Fiji/Tonga in the north and down to the eastern North Island of New Zealand ... 0
6) the zone that runs the full length offshore of western South America ... 1 known
and finally
7) the subduction zones offshore of Central America .. Mexico and south to Nicaragua ... 0

There are no other megathrust zones anywhere else in the world that would be capable of a M9+ event
( I was tempted to include the Tibetan megathrust. It has produced several M8+ events, but the main
problem with it is that it a very segmented fault zone and therefore it is difficult for it to build up enough
stress to produce a M9+ event before one of the smaller segments breaks in a M7.x to M8.x event.

All these zones can and do regularly produce M8.0 - 8.9 events ( and obviously smaller ones).
But it will take a significant section of one of these megathrust zones to be inactive for a very long time
( that includes no M8+ events), for it to build up enough stress and strain to be able to produce a M9+
event. Build up time, going by previous data, in the order of 300-500 yearscheers
Dave

 

[DaveC426913]

No argument that it likely had an effect greater than a 10.0 earthquake, but it was NOT an earthquake, which is the subject of this thread.

Interestingly a 10+ earthquake is called "Meteoric".

https://simple.wikipedia.org/wiki/Richter_scale
(It also happens to note that the Chicxulub Impact would have been a Magnitude 13 event. Or 1000 times more powerful than a 10, releasing 32³ times the energy.

 

[DaveC426913]

Some cool animations of the recent quake rippling across North America.
https://twitter.com/IRIS_EPO

 

[DaveE]

Here's an interesting interview with Lucy Jones (USGS/Caltech). If you jump ahead to 14:00 she talks about how large earthquakes can be. She says it's a function of the fault area, which is mostly determined by the fault length. However, the whole thing is worth watching, IMO.
She says the largest was 9.5 in Chile.

 

[phinds]

And most of them are, especially the larger ones, but impacts, isostatic adjustment, mass wastage, volcanic activity, etc are also sources. (The current Mars probe, Insight, is designed to measure Marsquakes and proper attention has been given to distinguishing small impact events from "true" quakes.)

Yeah, I had completely forgotten about it but I read an article fairly recently talking about all the fracking-induced earthquakes in Oklahoma in the last few years.

 

[FactChecker]

Regarding earthquakes caused by tectonic plate motion, I think that the real factor that reduces the odds of a magnitude 10 earthquake is not the lack of energy. It would be that smaller earthquakes would release the energy before it reached that large magnitude.

 

[davenn]

Regarding earthquakes caused by tectonic plate motion, I think that the real factor that reduces the odds of a magnitude 10 earthquake is not the lack of energy. It would be that smaller earthquakes would release the energy before it reached that large magnitude.

No, your reasoning is unsound. This is well disproved, every year, year after year.
If that were the case, we would never get the big quakes that we do.

It really is a case of there not being large enough faults to produce anything over
around a M9.5Dave

 

[DaveC426913]

If that were the case, we would never get the big quakes that we do.

No. If that were the case we would rarely get the big quakes we do.

And indeed, big quakes are much rarer than small quakes...

... partly because the small quakes relieve the pressure before big ones can occur.

 

[davenn]

No. If that were the case we would rarely get the big quakes we do.

And indeed, big quakes are much rarer than small quakes...
View attachment 249278

... partly because the small quakes relieve the pressure before big ones can occur.

Again, NO, you, like the other poster, are not understanding

this is, as I said before, well disproven... it's a numbers thing.
The number of small events needed to release the energy of a much larger event are HUGE
And there are never the numbers of smaller events in a particular area to stop a larger event occurring. As a result, the strain in that area continues to build up till it finally releases in a major M 7++ event

Large events are regular
M 7.0 - 7.9 avg 18 per year
M 8+ avg 1 per year

 

[FactChecker]

@davenn, My statement may indeed be wrong, but IMHO your argument does not logically contradict what I said. I am not sure that there is enough strength in the plates to realistically hold together until an M 10 occurs, but I am not an expert. In fact, there have been a great many smaller events already without an M10 and there may be a great many more before one occurs. So their cumulative energy released might eventually be enough to equal an M 10.

That being said, I see what I think is your point that the energy required might make it so rare that we just have not seen one yet.

 

[davenn]

but IMHO your argument does not logically contradict what I said.

Yes it does. There's no reasonable or scientific grounding in stating that a lot of small quakes will stop the occurrence of a much larger event. As I hinted at in my previous post responding to DaveC,
if lots of small quakes released enough energy to prevent larger quakes then we wouldn't even see the larger quakes that we do see happen.

I am not sure that there is enough strength in the plates to realistically hold together until an M 10 occurs, but I am not an expert. In fact, there have been a great many smaller events already without an M10 and there may be a great many more before one occurs. So their cumulative energy released might eventually be enough to equal an M 10.

It's pretty much agreed in the seismological world that there isn't a plate boundary on Earth large enough to accumulate the stress needed to generate a M 10 event
We don't get those great numbers of smaller events that you refer to, it just doesn't happen.

A M4 is 10 x greater than a M3
A M5 is 100 x greater than a M3
A M6 is 1,000 x greater than a M3
A M7 is 10,000 x greater than a M3
A M8 is 100,000 x greater than a M3 etc

you can do that for any magnitude quake
And the energy released is 32 x greater with each step

Even a bunch of M 6 events isn't going to stop a M8 from occurring in a specific
large subduction region. Wayyyyyyy up the page I listed the various large subduction regions
around the world and the numbers of known large events on them. Maybe you didn't read the
whole thread ?

Think on this for a minute
A M 10.0 is 10 times greater than a M 9.0
32 times more energy released than a M9.0 !

Look at the top of that graphic that @DaveC426913 provided a couple of posts ago. If you were willing to do the math (I'm not/ nor able to) I wouldn't be surprised if it was more energy released that all the nukes in the world detonated at once and many times over

Dave

 

[FactChecker]

It's pretty much agreed in the seismological world that there isn't a plate boundary on Earth large enough to accumulate the stress needed to generate a M 10 event

Maybe I wasn't clear. I think this is exactly my point. Before the energy, forces, and stress are great enough to reach the M 10 level, the plate would have already broken and there would have been one or more lower-level earthquakes.
There may be other reasons that an M 10 is not possible, but I think you have confirmed the one that I proposed. If you are saying that there is not enough energy in the interior of the Earth to create an M 10, I doubt that very much.

 

[phinds]

There may be other reasons that an M 10 is not possible ...

Personally, I think the point that he has made (over and over) is that plates just can't DO that. It's irrelevant how much power there is in the Earth's core, it just can't build up to an M10 in the plates, and your point of view is in direct contradiction to what he has said.

 

[FactChecker]

Personally, I think the point that he has made (over and over) is that plates just can't DO that. It's irrelevant how much power there is in the Earth's core, it just can't build up to an M10 in the plates, and your point of view is in direct contradiction to what he has said.

I interpret that as saying that they would brake first at a lower intensity. That is what I said (or meant to say) in the first place. But he says that I am wrong. Maybe I am misinterpreting something.

 

[phinds]

I interpret that as saying that they would brake first at a lower intensity. That is what I said (or meant to say) in the first place. Maybe I am misinterpreting something.

My interpretation is that there is no way that any known tectonic plate (and they're all known) could build up with enough energy for an M10 REGARDLESS of smaller quakes. @davenn said exactly that, clearly, I believe.

 

[FactChecker]

My interpretation is that there is no way that any known tectonic plate (and they're all known) could build up with enough energy for an M10 REGARDLESS of smaller quakes. @davenn said exactly that, clearly, I believe.

So you are saying that they can not have enough mass, velocity, or force? Or are you saying that there is another way to dissipate energy rather than a lower magnitude quake?

In any case, I do not want to hijack this thread with my amateur theory.

 

[phinds]

So you are saying that they can not have enough mass, velocity, or force? Or are you saying that there is another way to dissipate energy rather than a lower magnitude quake?

I'm not saying anything, I'm repeating what Davenn said and that only because I believe you have misinterpreted what he said. He's the one that will have to stand by his statements but it very much sounds to me as though he knows what he's talking about.

 

[FactChecker]

I'm not saying anything, I'm repeating what Davenn said and that only because I believe you have misinterpreted what he said. He's the one that will have to stand by his statements but it very much sounds to me as though he knows what he's talking about.

Ok. I'll buy that and just leave it there. Thanks.

 

[davenn]

If you are saying that there is not enough energy in the interior of the Earth to create an M 10, I doubt that very much.

I'm not saying that ... never even hinted at it

The energy if the centre of the Earth isn't really relevent

 

[DaveC426913]

this is, as I said before, well disproven... it's a numbers thing.
The number of small events needed to release the energy of a much larger event are HUGE
And there are never the numbers of smaller events in a particular area to stop a larger event occurring.

I see. That is a lot more clear now.

 

[eachus]

There is one scenario that can result in a magnitude 10 earthquake. A caldera like Yellowstone but located near a plate boundary--lots of them in the Pacific near or even part of the ring of fire. Think of a VEI 8 eruption as firing a really big gun upwards. (Gigatons of ash will reach the stratosphere.) The recoil will push down, and if there is a descending continental plate under the plate with the caldera, the entire boundary between the two plates could rip free. (The top plate would be rebounding as the lower plate is still descending.) This can't really cause a mag. 10 in the Pacific Northwest--the Juan de Fuca plate is too small. How much energy is available from slamming the Mariana trench closed? There isn't a known caldera nearby, but there are lots of sea bottom volcanoes that are not known until they erupt.

A very low probability combination of events? Sure. But likely enough that it has probably occurred more than once in Earth's 4.5 billion year history. But if you want to worry, a Megatsunami is likely to nuch more damage and loss of life than a Magnitude 10 earthquake. Or to phrase it differently, tsunamis associated with earthquakes have often been the largest cause of damage and loss of life.

 

[FactChecker]

It seems that the uplifting of the great mountain ranges like the Rockies, Alps, Andes, etc. would supply enough energy for magnitude 10 earthquakes if the techtonic plates got stuck enough to release energy in a single large earthquake. What would one call the processes that release such energy in small, continuous increments that prevent stresses to build to that extent?

 

[Bystander]

in small, continuous increments that prevent stresses to build to that extent?

"Orogeny" the word you're looking for?

 

[phinds]

"Orogeny" the word you're looking for?

To add to that:

The processes of orogeny can take tens of millions of years and build mountains from plains or from the seabed.

Hardly sounds like an earthquake

 

[davenn]

It seems that the uplifting of the great mountain ranges like the Rockies, Alps, Andes, etc. would supply enough energy for magnitude 10 earthquakes if the techtonic plates got stuck enough to release energy in a single large earthquake. What would one call the processes that release such energy in small, continuous increments that prevent stresses to build to that extent?

That's the whole point, it is in increments, not a bunch of M10 events. There is no comparison
and as stated several times, there just isn't a plate boundary capable of accumulating enough stress
to produce a M10. The friction on the fault surface is overcome before enough stress can accumulateD

 

[ElliotSmith]

A M10 is 5 times more powerful than the strongest quake on record, which was a 9.5 in San Francisco, which happened in 1906.

 

[FactChecker]

That's the whole point, it is in increments, not a bunch of M10 events. There is no comparison
and as stated several times, there just isn't a plate boundary capable of accumulating enough stress
to produce a M10. The friction on the fault surface is overcome before enough stress can accumulate

This is exactly what I had in mind in my first post, #14. In my ignorance I expressed it as energy released in smaller earthquakes. My thought was that something (be it friction overcome, smaller quakes, or something else) would happen before an M 10 level of stress was reached.