California Earthquakes Disrupted HF Propagation on West Coast | Hacker News Reader

California Earthquakes Disrupted HF Propagation on West Coast

arrl.org

218 pointssciurus95 comments

>RF Seismograph showed an increase in noise on 80 meters some 13 hours beforehand, as well as some propagation changes on 40 and 30 meters — low before the quake and increasing in its wake.

Hours. Hours beforehand. Having that much preparation would be life-saving. Especially for us living near the Cascadia Subduction Zone.

I don't think it has been consistent as far as observations go, so its usefulness in prediction seems unknown at this point.

Keep in mind that this report has come about with zero peer reviewing (I think it's a little strange it's been published by the ARRL to be honest), and another thing that is missing is that it needs to be correlated with solar activity, operator activity, local noise, and even thunderstorm activity, among other influences, before one can validate a change in HF propagation is a precursor to earthquakes.

All these things sound like stuff which can be controlled for.

Absolutely, but it just needs to be done.

Because there are also a million other correlations with the earthquakes which are just coincidences.

-Which is all the reason I need to bring up Tyler Vigen’s amazing spurious correlations:

https://www.tylervigen.com/spurious-correlations

That's hilarious. Would be cooler if they could limit it to stuff with the same units though!

> Keep in mind that this report has come about with zero peer reviewing

This report, maybe, but even the article includes links to previous ones which have.

Here’s one, but if you click through to the project’s website you’ll find more.

http://www.ep.sci.hokudai.ac.jp/~heki/pdf/Scientific_America...

I've always assumed that piezoelectricity would occur in the crust before and during an earthquake given the prevalence of quartz - it's my go to theory for the now undeniable sightings of earthquake lights.

The U.S. Geological Survey does issue notifications when they detect significant seismic activity that's a potential precursor to larger events. But as many people have already mentioned, there still is no known model for predicting earthquakes.

With inexpensive, distributed RF software defined radios, we could rapidly collect data and use machine learning to see if a pattern presents itself based on changes in HF propagation.

For a similar example, check out https://www.lightningmaps.org/?lang=en. They use inexpensive, freely colocated time of arrival RF receivers to triangulate lightning strikes across the world [1]. It operates on a shoestring budget as a hobbyist project.

There might be no signal to be found, but it seems from a cursory glance that to investigate would be a low cost exercise.

[1] https://i.imgur.com/dUxnTsR.png

How often does this RF Seismograph show disturbances when no earthquake follows?

Only if the test has high specificity. If this RF noise happens frequently when there is no earthquake, it is of little value.

Little PR value, to be sure- but still fairly valuable if someone can identify the causal factor and more specifically measure that.

RF Seismograph showed an increase in noise on 80 meters some 13 hours beforehand, as well as some propagation changes on 40 and 30 meters — low before the quake and increasing in its wake

Does this mean my cat is tuned in to ham frequencies? She was not right in the hours before the 7.1, and once the shaking stopped she was back to her normal self.

I had a cat growing up and he always acted very strange before significant earthquakes.

Did your cat ever act very strange at other times?

Did significant earthquakes ever occur when your cat was acting normally?

The classic parody textbook "Science Made Stupid" theorized that earthquakes are triggered by vibrations from agitated animals.

(http://www.chrispennello.com/tweller/ , page 38)

There are other things that can cause E skip to stop working (solar activity is the big one) so while it is good to say "hey propagation just changed, what's up?" it isn't reasonable to say "Earthquake inbound!"

That said, there is interesting work in geology to more accurately characterize this mechanism. The last paper I saw was reference in Science News indicated that pressure on granite (which has a peizo-electric effect) might be the underlying mechanism. I haven't seen any follow up on that hypothesis though (proving or disproving). It would seem pretty straight forward for the seismograph sensor makers to add an E field strength meter to observe this effect if it occurs.

The creator of FiveThiryEight, Nate Silver [1], had a great chapter in his probability book about the global efforts to detect earthquakes and there have been tons of research over the last century (including radio). With many people claiming to have found solutions only for them to quickly fail.

With current best-effort science it’s basically impossible to detect them ahead of time, particularly with any relevant geographic accuracy. At most only a probability figures within a 10-100yr+ range over a very broad area seems to be the best they can do. Fault lines can encompass hundreds of towns and cities.

Even if they detected the Cali quake before hand from Vancouver there is no way they could pin point that in any reasonable way to evacuate particular towns AFAIK.

1: https://books.google.ca/books?id=SI-VqAT4_hYC&lpg=PP1&pg=PA1...

The YouTuber Suspicious0bservers somewhat predicted the Quakes via Space Weather: https://www.youtube.com/watch?v=ISfueR4vAhQ. His channel and research are interesting.

Most interesting is that interference began before the earthquakes hit. Is that already a datapoint that is being used in earthquake predictions?

That is interesting... My first guess upon seeing the headline was that the earthquake could have caused some key point-to-point microwave links to be misaligned. But no - for those not reading the full article - it's actually an electromagnetic field caused by the earthquake being propagated up into the atmosphere...

Take with a grain of salt. This is pseudoscience at best.

There were some reports of earthquake lights[1][2][3] and earthquake clouds[4][5][6] recently.

There's some online communities dedicated to those, e.g. https://quakewatch.net/predictioncenter/

___

[1] https://en.wikipedia.org/wiki/Earthquake_light

[2] https://www.mirror.co.uk/news/weird-news/men-film-glowing-sn...

[3] https://www.dailystar.co.uk/news/weird-news/789760/Colorado-...

[4] https://en.wikipedia.org/wiki/Earthquake_cloud

[5] https://weather.com/vertical/video/strange-clouds-seen-in-co...

[6] https://www.denverpost.com/2019/06/20/boulder-rare-helix-clo...

Edit: I mean accurate forecasting and prediction using this data is pseudoscience.

What does that cloud formation have to do with earthquakes? That cloud was filmed in Boulder, not anywhere near southern California. The light thing seems pretty neat and there looks to be a bunch of possible explanations for the source. Although some of the videos I watched looked more like flashes of electricity coming from powerlines snapping or transformers blowing which could definitely happen if the earth was shifting.

I'm just the messenger, I have not spent any time researching the details of those claims.

There's some overlapping between some online communities I participate in and the doomsday preppers/tracker community so that's why I stumbled on this.

The Wikipedia page for Earthquake Lights talks about lights as far as 740 km from the epicenter, so I'd bet that's the answer people who associate those with the quakes will tell you.

As I said take it with a grain of salt.

> What does that cloud formation have to do with earthquakes?

Last I read about the alleged phenomena, you're supposedly looking for straight line or ripple clouds that form in seconds. The explanation is that some mechanism (originally friction) is boiling groundwater; but proponents can no longer agree on what mechanism leads to formation of the clouds.

Why would earthquakes cause a significant amount of groundwater to boil?

Supposing there were enough water vapor to do that, how would boiling groundwater form clouds at all, much less in seconds? There's still a lot of earth in the way between the fault and the sky.

Ground shaking does not mean that energy is converted into heat. Does the ground feel hot after an earthquake? Warm at all?

Earthquakes, right? Not volcanoes or magma chambers? If this phenomenon were real, wouldn't you expect it to occur right before a volcanic eruption, which actually involves large amounts of magma, near the surface, which could actually vaporize large amounts of groundwater? As far as I can tell, that doesn't happen either. The water vapor erupts with the molten rock, and mainly condenses into volcanic clouds because it has volcanic particles to condense around, not because the water vapor itself is enough to form clouds on its own before dissipating.

Sure, but it’s still an interesting observation. Seems like it would merit further investigation to see if there was a related causal mechanism.

It's more than just pseudoscience. There are reports of animals being able to predict earthquakes before they occur, and even records of other kinds of electromagnetic activity before quakes.

I worked on a project at Stanford that set up EM sensors around the bay area to possibly detect signals before major earthquakes.

I mean, right now it's all purely hypothetical but it's absolutely worth trying to find it if it's there, and compeltely within the realm of worthwhile science.

> There are reports of animals being able to predict earthquakes before they occur, and even records of other kinds of electromagnetic activity before quakes.

There have been all kinds of tests with animals but so far, all animal behaviour that looks like predicting earthquakes is only their sensitivity to low amplitude-high speed P (pressure) waves, which humans usually don't feel.

Pigeons are very sensitive to this. Apparently a survival instinct from making their home in cliff faces.

It seems to trigger a flight reflex, it makes them take off real fast. I use a high voltage arc generator to scare pigeons off my deck. The sound from the arc seems to trigger the same response. It is certainly much more effective than yelling at them or waving one's arms around.

I forgot the exact details of the research as I did it in undergrad, but I guarantee my academic adviser, the PhDs at the USGS, and the people providing the grant thought of that.

There's evidence for real prediction, including reports of a ramp up EM energy a day before a quake.

> There are reports of animals being able to predict earthquakes before they occur, ...

No offense but talk to people who have had "psychic readings" performed and plenty of them will swear to you that psychics are, in fact, 100% real.

Even if an individual believed a psychic has some kind of supernatural power, as a society, we large understand the mechanics of how psychics do their thing.

With animals, we have no clue why there appears to be a tendency for them to act oddly before an earthquake, and up until recently, we didn't understand how birds could navigate as effectively as they do.

It's possible that what we see with animals is just coincidence or an artifact of how we perceive our own memories after traumatic events, but it's also possible that an animal or some set of animals can perceive something associated with certain earthquakes.

It's also possible there exists a teapot on the other side of the sun. One day our science will be able to tell us but until then we it is still possible.

Perhaps you would be better served with some humility about your understanding of science. Science involves searching the natural world for evidence for certain phenomena. Yes, sometimes informal observations warrant formal research.

People have researched ESP and debunked it. Currently, we are still researching earthquake prediction.

No one is claiming anything supernatural is occurring, of course. There may be real changes in the earth's crust before earthquakes which send out signals we haven't yet found.

Have you been in an earthquake before? I remember sleeping during a quake and then waking up right before the main shock hit. I’m not sure what woke me up, it could’ve been a preliminary shock, but I very vividly remember being jolted awake right before the earthquake wave hit. It’s entirely possible that an electromagnetic wave precedes a shock, but it’s unlikely that there are significant waves hours beforehand if there’s actually a causal relationship to the movement of the plates themselves.

It would be far more likely that the EM pulse happens with slightly faster propagation than the kinetic pulse (like milliseconds, not hours).

I’ve experienced a number of them and never felt anything leading up to them.

The last decent one I can remember was a few years ago around maybe 2 or 3 AM and made my apartment roll back and forth. The rolling woke me up but my partner slept through it. And I tried not to panic so they could just sleep through it, hoping it would end soon.

Also, we didn’t have anything hanging or that could easily fall onto our bed in the bedroom so I think staying in the bed was an okay move.

I live in a single family home now even higher up the Twin Peaks area of SF so who knows how this house will handle the next one. Hopefully it won’t be too bad. At least the ground is solid and not considered a liquefaction zone. And my new neighbors seem to have some kind of thing going on where they stock first aid supplies for first responders in disasters which seems nice and thoughtful.

Though I just don’t understand why SF won’t use our missile warning system for earthquake warnings. Seems like they could make a special earthquake tone and warn everyone if one happens in another city and is heading our way. Even seconds of warning would be so helpful. Could be the difference in being able to jump under a table or desk vs. getting crushed by falling stuff.

There are three types of waves that travel through the earth's crust during an earthquake at different speeds: primary, secondary and surface waves, which arrive in that order.

Perhaps one of the first two waves woke you up, and then the surface wave is what "felt" like an earthquake to you.

In fact, earthquake warning systems detect P-waves early, send out alarms, and give people a few seconds to stop subways and get outside before the surface waves roll in. It's not the same as earthquake prediction, though.

Do you how fast these waves travel versus sound in the atmosphere? Or, how these waves themselves might sound qualitatively when they shake nearby structures in the air?

On more than one occasion, I think I've anticipated an earthquake based on sound. I can only describe it like an approaching but amorphous activity, a bit like when large flocks of birds take to flight over an open field or when a wind gust goes through a forest.

I think I've noticed this sound only with relatively nearby epicenters (5-25 miles). The very distant ones usually seem more silent and my first recognition is the jiggle and displacement, or perhaps the creaking sounds of the surrounding structure if I am indoors.

This. My wife was in her backyard with her dad during the Loma Prieta quake, and a few minutes before the quake they saw a momma possum with her babies climb down the side of the house and walk off into the bushes.

It could be a coincidence, but reports of animals acting oddly before quakes aren't uncommon, and we've recently found a plausible biological basis for how birds sense magnetic fields, so some animal or animals may be able to detect signs that an earthquake is more likely to occur.

" they saw a momma possum with her babies climb down the side of the house and walk off into the bushes"

I don't understand. What would a possum do instead if there was no earthquake? Stay on the house? Walk out into traffic on a highway?

> What would a possum do instead if there was no earthquake? Stay on the house?

During daytime? Yes, mostly, IIRC, they are nocturnal and come down during the day mostly when in food distress or disturbed.

But, of course, if you saw a possum come down (perhaps from hunger, or because a crow dropped a husk on it and disturbes it, or whatever) without a near-following earthquake, you might say “Hmmm, odd”, but it wouldn't be a major notable event. But two uncommon events near in time get linked mentally, even if there is no relationship.

there's plenty of interesting mechanisms that are very plausible, e.g. piezoelectric pressure buildup.

Care to elaborate on why you call it pseudoscience? I disagree

I meant accurate forecasting based on those is pseudoscience. The phenomenons themselves are real.

Pseudoscience? From TFA:

““The earthquakes show up as RF noise because of the electric field lines, now scientifically confirmed to change the way the ionosphere reflects RF,” Schwarz said.

Schwarz has cited an article in the October 2018 edition of Scientific American, which, he says, explains the phenomenon. (See Erik Vance’s “Earthquakes in the sky,” Scientific American, October 2018, p. 44.)“

I meant accurate forecasting based on those is pseudoscience. The phenomenons themselves are real.

To me, "pseudoscience" means that the approach isn't grounded in the scientific method. It's not pseudoscience to collect data to try to predict a phenomenon, even if the prediction isn't successful. That's like saying "well, we set up this experiment to test if there's a link between x and y, but when we looked at data in this one particular way, the results weren't significant so this entire field is pseudoscience."

I'm sure scientists could find a way to use this data. What I'd call pseudoscience is people online sharing photos of clouds and then stocking on water and food. You are right that it is scientific, but it's dangerous to make claims like this.

As I read the article it is possible to notice them after the fact but difficult to tell the difference between them and the normal changes as you go from day to night thus making prediction dicey at best.

You mean like this? http://ericpdollard.com/2014/06/23/the-landers-facility-of-e...

Seismologist here. So far, no reliable predictor of main shocks (largest earthquake in a sequence) has been found. People have been looking for them ever since the invention of the modern seismometer networks in the 60s.

Most of the EM based earthquake prediction is based on really loose reasoning. In summary, it goes like this: "earthquakes can generate EM fields through piezo-electric effect, therefore small movements before big earthquakes should generate small EM fields we can measure". But there is almost never no such thing as "small movements before big earthquakes", which is why reliably predicting them has been impossible so far.

Most likely, this will turn out to be an example of confirmation bias. In the unlikely event that it is not, people will be all over this.

To be fair, there are some well documented EM precursors. The most classic is from the 1989 Loma Prieta earthquake: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/GL01... Recently, some fairly convincing ionospheric-related (i.e. GPS delay) precursors have also been observed before Tohoku and (less convincingly) several other major earthquakes. (e.g. Heki, 2011, Iwata & Umeno 2016, and several other references I forget. Mostly from the same couple research groups.)

We don't have a full mechanism to explain them (or, rather, there are a lot of competing mechanisms that don't fully explain things). More importantly, precursors don't seem to occur consistently as you noted.

However, they're also not worth automatically dismissing. The idea that they're all a simple case of confirmation bias has been extensively discussed, and while it's not currently possible to refute, it's starting to seem less likely. There's certainly been a lot more attention given to possible precursors and mechanisms in the last 5 years than there were before. It's a serious avenue of research right now. Keep an eye out then next time you're at AGU. I guarantee you you'll see at least a few posters around possible precursors and/or precursor mechanisms.

Forecasting is definitely pseudoscience, but EM-related precursors are a fairly hot (and controversial) research topic at the moment.

> Forecasting is definitely pseudoscience, but EM-related precursors are a fairly hot (and controversial) research topic at the moment.

It's not pseudoscience because it can be disproven--which is generally what happens.

The issue that everybody forgets is that predictions have FOUR outcomes, not two.

You have the one everybody remembers: "I predicted X and X happened".

You have the one some people remember: "I didn't predict X and X didn't happen."

You have the one that people rarely remember: "I predicted X and X didn't happen."

You have the one nobody remembers: "I didn't predict X, but X happened."

The problem is that for rare events, the "predict X and not X" and "didn't predict X but X" have to be REALLY low probability for a measure to be useful.

Didn't predict X but X can be high probability and it still be a useful predictor. Reporting even 10% of earthquakes hours in advance would be useful.

Predict X and not X is a huge issue though, as you suggest.

I don't see anything like a blackout: https://pskreporter.info/cgi-bin/pskstats.pl

For those who don't know, PSK reporter is a system for logging propagation reports using digital modes like PSK and FT8, mostly on HF amateur bands (incl. 80,40,30m).

You might expect to see some kind of effect on July 4 if this effect were as widespread as described in the article, but to my eye it looks like a normal day.

Oh wow, an old school Perl CGI script! I remember doing those about 20 years ago. Neat.

Serverless lambdas, before they were cool!

It's surprising to read about, but not implausible. You put that much stress on crystalline material over miles and who knows, you could get piezoelectric kinds of effects creating huge EM fields.

Interesting, this would be a problem for emergency communications set up to run on HF if it did indeed cause a total blackout. I know the VA out here uses HF for emergency communications in the event of a major disaster, I believe 80 meters. This would be a problem if a major earthquake killed propagation.

20m seems to have suffered less, which is good to keep in mind.

intresting article about the phenomenom: http://www.ep.sci.hokudai.ac.jp/~heki/pdf/Scientific_America...

What’s HF?

High frequency radio band

Also known by the public as "shortwave radio" (although only a part of the HF spectrum is used for commercial broadcasting, but HF and shortwave is essentially used interchangeably).

generally defined as 3mhz to 30mhz.

Yes! For those not familiar with radio, HF (high frequency) is a frequency range that's higher than what's used for AM broadcast and lower than FM broadcast. Much lower than frequencies used in WiFi and cell phones.

What makes it interesting here is that it's a frequency range that is commonly-used and that also propagates in modes other than line-of-sight. For instance 'groundwave' propagation curves around the Earth because of induced currents in the Earth.

This allows HF communication over the horizon. Enthusiasts are regularly able to make contact between continents with amplifier power of less than 5 Watts.

I think groundwave propagation only happens reliably at the extreme low end of the HF spectrum, and is mostly associated with medium and long waves (160m ham band & AM radio for example).

For most of the HF spectrum reflections off the ionosphere are the main useful propagation mode. At the short end (like CB radio) bouncing of the ionosphere is harder so line-of-sight is more common.

Yep.

https://en.wikipedia.org/wiki/Ground_wave_propagation

https://en.wikipedia.org/wiki/Skywave

https://en.wikipedia.org/wiki/Radio_spectrum#ITU

Others have answered, so I'll just add that you might be familiar with the even-higher bands VHF and UHF. HF is neither very nor ultra :)

So if earthquakes do generate "electric field lines", can we tap into that and generate electricity from those field lines? And, if so, since that would be "stealing" energy from the quake, could it diminish the quake intensity? Theoretically.

It's energy that's already left the quake. It's not like wave generators stop earthquakes which cause tsunamis.

Next in the agenda: stealing energy from lightning.

https://engineering.mit.edu/engage/ask-an-engineer/is-there-... TIL a lightening bolt is a nickle's worth of energy.

TIL that 1.21 gigawatts is $.05.

It's 1.21 gigawatts, but only 0.25KiloWatt/hours.

TL;DR: a literal nickle. The article estimates that a typical lightning bolt contains only about 0.25kWh, which is surprisingly little, if you put it like this.

I always thought lightning bolts had something closer to a megawatt-hour, so thanks for clearing that up for me!

A megawatt-hour is enough to power a small/medium data center for an hour. Or to power tens of thousands of homes for an hour.

A lightning bolt lasts for seconds at best, so not sure why you’d think it’d provide megawatts for a duration of an hour. That would mean the instantaneous current would need to be much higher than a terawatt, which is several orders of magnitude higher than what it is.

For the purpose of generating electricity, I would expect very low energy from these fields in any localized area - and thus no efficient way to capture a significant amount of that energy. It would be more or less comparable to generating electricity from existing background radio noise.

As for the purpose of weakening earthquakes, this energy may as well have already left the system - it's propagating away from where the problem is. This article is like saying that exhaust from a car engine decreases air quality. You could harvest that exhaust but it won't affect the engine. If somehow you did have enough pressure and containment to keep the exhaust from leaving the engine at all, that would have some effect. But if we could do that EM fields over all of California, I think that would have bigger effects on the planet than weakening the occasional earthquake. That's like a Star-Trek-level of control over a planet.

Eric Dollard is giving a talk later this week about this, and he's been talking about this stuff for YEARS.

Some people here are excited about hours... but this guy can detect these things DAYS in advance.

Preview: https://www.youtube.com/watch?v=VE3QR3QUUd4