Seismologists suspect earthquake on San Andreas Fault is imminent | Hacker News Reader

Seismologists suspect earthquake on San Andreas Fault is imminent

phys.org

67 pointswglb62 comments

I sat in on a lecture by a Stanford geophysicist, and he said that seismologists have every legal incentive to communicate that a large earthquake is imminent in the Bay, even if their work is inconclusive or suggests otherwise.

They might get sued or prosecuted if they say it’s safe and a big one strikes.

That seems odd. What would be the basis of such a lawsuit?

https://www.theguardian.com/science/2012/oct/22/scientists-c... perhaps.

Wow that’s fucked up

Edit: looks like they eventually were saved in appeals court https://www.nature.com/articles/515171a and finally completely cleared after their Supreme Court ruling https://www.science.org/content/article/italy-s-supreme-cour...

Still a lot of time and money wasted on absolute bullshit.

That was Italy, not the US.

Are there any other professional category that gets sued if they don't predict disaster within tight timing?

Imagine suing epidemiologists because they didn't predict Covid-19 in a timely manner.

No epidemiologists were going around saying "eh it could never happen". In fact, many of them were warning after SARS. Trump actually took apart Obama's virus disaster-readiness warehouses and other programs in 2018-2019. Very bad timing, many such cases!

I would suspect the majority of disaster-related experts are not going to be so laid back.

Yeah but couldn't seismologists just never say anything about the matter?

Similarly, I've known of a psychic who was known for regularly making catastrophic earthquake predictions. Naturally he was wrong 99 times out of 100. But that 1 he got right was enough to build his whole career. "The Great Zambini, who predicted the 1998 earthquake"... People just forgot all his misses, only remembered his hit.

That will not happen in the US court system. Also, the Guardian article below about this happening to scientists was in the Italian court system, not the US.

Nearby Corcoran has been subsiding at up to 60cm per year (from water extraction). Seems like quite the area.

https://earthobservatory.nasa.gov/images/89761/san-joaquin-v...

60 cm!!? Wow.

Funny. In with the roar of multiple paragraphs spent explaining all the reasons this spot will be the next big one. And then out with a quick whimper that the scientists are not convicted.

Didn't happen in the last five days either. Does that make it more likely or less?

I’m an independent statistic who don’t need no covariant!

And then out with a quick whimper that the scientists are not convicted.

Well, no, this isn't Italy.

I think op is referring to a TS Elliot poem

This is the way the world ends

Not with a bang but a whimper.

---

Excerpt from The Hollow Men by T.S. Eliot[0].

I'll have to add it to the page, but it was also used as the introduction for The Compound by S.A. Bodeen[1]. It's an interesting young adult novel about a family living underground in a state of the art bomb shelter after a nuclear attack occurs.

[0] https://en.m.wikipedia.org/wiki/The_Hollow_Men

[1] https://bookshop.org/p/books/the-compound-s-a-bodeen/1554853...

We would also have accepted, "The best lack all conviction / While the worst are filled with passionate intensity." Even though that's Yeats.

Actually, I think the reference might be to this:

https://www.theverge.com/2014/11/11/7193391/italy-judges-cle...

Whereas GP is making reference to a case in which Italian seismologists were literally convicted after their predictions did not come true.

Convinced? :-)

Likely what they meant, but convicted could be correct here, in that the scientists may not have much conviction in their assessment, i.e. do not feel certain.

Um, no. Right from the start of the article it was clear this was a relatively small, periodic family of earthquakes, nothing like "the big one".

Earlier warnings:

https://news.ycombinator.com/item?id=23823917

https://news.ycombinator.com/item?id=24116552

https://news.ycombinator.com/item?id=19701182

https://news.ycombinator.com/item?id=23823917

https://news.ycombinator.com/item?id=11634338

I think this line is (a) most accurate and (b) rings true to your list

"as is always the case with earthquakes, everyone will just have to wait and see what happens"

Oh well, off to watch a B-Grade disaster movie then ..

In Parkfield CA. Halfway between LA and SF.

The earthquake might cause unexpected damage. The Crystal Springs reservoir sits right on the San Andreas fault line. The reservoir supplies drinking water to the SF county and San Mateo county, all the way to Palo Alto. An earthquake might drain the water underground, disrupting water supply to a million people.

Reading this article it says that scientist expect an earthquake because every 22 years it pops and it's due, however, there are no signs indicating that it will soon so therefore scientists won't make a formal prediction. Am I reading this incorrectly?

I'm a non-Californian, so I'm not very familiar with the tectonics at play here.

If there's an earthquake on this fault, how bad would it be? Would it trigger a tsunami? Would SF and LA be damaged?

Could this cause "the big one" that gets mentioned occasionally? How bad would such a quake be?

San Andreas is a transform fault, also known as a 'strike-slip' fault.

These generally do not cause as much damage as a subduction zone event, also known as dip-slip. An example of this type of event (dip-slip) would be the 2004 Indian Ocean earthquake, or the violent 1700 Cascadia Megathrust Earthquake.

Personally, Cascadia is /more/ dangerous than any strike-slip earthquakes like SA. We have sedimentation records of massive Cascadia tsunamis going back to about ~900CE.

One thing which isn't discussed enough is how bad the Tsunami is environmentally. The coastline of Japan is absolutely littered with crap from the 2011 Tsunami. All manner of chemicals were sucked into the nearby sea, tires, carpets, hard and soft plastics, absolutely everywhere. It almost looks unrecoverable.

I know that seems like a non-issue in the grand scale of things, but Tsunami's of the past didn't do this. Most pollution was biodegradable.

I can't imagine what the coast of LA would look like after a similar event :(

More of a concern in the bay area, the geological composition is sand, mud, basic river delta sediments--not the most stable stuff.

eg: During a hypothetical Earthquake in the Bay area, the liquefaction of sand occurs, which causes underground structures to move upward due to buoyancy (think of a lower level parking garage), and the soil mass from the structure collapses.

the liquefied sand diffuses to the surrounding area after the earthquake, causing the sand beneath the underground structure to be lost, and the building will return to its original position or even collapse.

Yeah, also quite bad, I've seen the aftermath of this liquefaction in Japan. Whole apartment blocks topped over with seemingly good foundations.

The Parkfield region is very sparsely populated. A disruption on this segment of the San Andreas Fault, comparable to past similarly-sized events, would probably NOT have significant effects in major populated regions of either the San Francisco Bay Area (San Jose is 128 miles north) or Southern California (Santa Barbara, which is the northernmost extant of the SoCal conurbanation is 110 miles south). That's roughly 120 and 180 km respectively.

Earthquakes' effects are most strongly felt immediately around the epicenter, and diminishes with the square of the distance.

The San Andreas Fault, being a strike-slip fault (plates moving laterally against one another) and lying principally inland has very low tsunami risk. Tsunami are most associated with superthrust faults, in which one plate rides up over another, and energy is release with a strong vertical displacement, as with the 2011 Tohoku and 2004 Indian Ocean earthquakes.

I wonder what happens if someone hits the fault with an explosive while it's in this state of "near-earthquake". Would it make it better by relieving pressure or make it worse by triggering the main event?

Basically neither really. the energy unleashed by even moderate earthquakes through natural tectonic tension release is proportional to the degree of accumulated tension getting released, and in all such cases, these tensions contain a potential energy that is far, far greater than what any normal nuke generates. In other words, a nuke placed in the San Andreas fault even with extreme care to have maximum impact, would probably do almost nothing against the much bigger energy, and resistance to its release, already going on.

A key thing is that with nukes or any large artificial blast, the energy is pretty much released in a compact area right out into the open. With earthquakes, energy is spread across large areas and often starts far underground, yet still causes damage over a very extensive area. This is part of why earthquakes are much more energetic then man-made blasts.

Large explosions (especially nukes) do produce earthquakes and minor seismic movement, but it just doesn't compare to the comparative megaton-equivalent forces that natural tectonic movements create underground during really notable earthquakes, just like the one being "predicted" in the article above.

The energy released by an earthquake of magnitude 8.0 on SA is approximately 6.31×10^16 joules. When converted to an equivalent in terms of TNT, this energy amounts to about 15,080 kilotons of TNT. (About the same as the Castle Bravo nuclear test)

Now, to use such a weapon to cause a stress-relief earthquake, some factors need to come into play: Depth at which the device should be detonated to optimize stress relief without causing surface damage. detailed seismic imaging and rock mechanics studies. Geometry of the fault zone.

Even w/ a Castle Bravo type test, massive radioactive fallout would occur in groundwater as well as air. There's also the chance that such an event would cause local volcanic activity.

>this energy amounts to about 15,080 kilotons of TNT. (About the same as the Castle Bravo nuclear test)

I thought of mentioning Castle Bravo or Tsar Bomba as contray examples of my general argument, but I simply stated "normal nuke". Neither Bravo or Tsar were at all normal nukes and especially by modern design standards that focus more on the multi-kiloton range and precision-guided multiple strikes against a given area target.

Even with those insanely giant old bombs, I wouldn't absolutely be sure that they'd achieve a massive tension release, even in a fault as tense as the San Andreas. Such a thing is likely just a bit too variable-prone to model effectively.

As for something like a Hiroshima type bomb doing it, bloody unlikely. The original post comment simply mentioned a bomb so I didn't want to stray into the biggest mega explosives of human military history.

Should I be worried ? I just landed at SFO

No.

For what it's worth, the last major earthquake here killed 63 people, the significant majority of which were on various freeways and bridges that collapsed. All infrastructure has undergone significant retrofitting since then.

Yes

The paper is actually science, but it’s not news. It is, however, being portrayed that way. This type of writing seems like a job that could, and possibly should, be replaced by AI.

I personally believe the Cascadia fault will go off on June 18, 2025, but I may be wrong!

That's one week before my birthday. Do you think you could push it back 7 days?

Yes, but just for you.

Describing this as "on San Andreas" seems deceptive. It's a particular unpopulated location.

It's "on San Andreas Fault", in the usual "the"-dropping style of headlines. The fault is named after the town of San Andreas but extends well beyond it.

The town motto of San Andreas explicitly disclaims responsibility for the geographic feature.

the town motto of San Andreas, California is "It's not our fault."

jinx

"it's not our fault"

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