The RF-Seismograph measures massive radio blackout during California earthquakes

And that’s a big problem with the fallacy of post hoc analysis. Plus, there is a human bias to remember occurrences associated with something memorable like an earthquake, but forget the rest which are not and merely routine.

For example, once in a while I might think of my mother and right then she telephones, which is memorable, but I don’t recall all the times I thought about her and she didn’t call. Such occurrences would convince some people that there must be a telepathic connection, even though there isn’t.

 

I have been sitting here, on the porch with my laptop reading the last page or two of posts. When suddenly I see a correlation between a June bug's motion flitting/flying against the laptop's screen. You know, seems like it's bobbing up/down and moving side to side. Then the light dawns! This thing is trying to answer some of the posts! The motions are what you'd see if the thing was writing cursive! Oh my! How do I record these movements? There's absolutely no telling what words of wisdom are being lost forever!

 

LP is the biggest quake I've experienced. I was working on instrumentation on a DC-8. The plane started to move back and forth and I heard a roar. Having heard a few tornadoes, it was the first thing that came to mind. I looked out the window and all the trees were bent to one side. Just as I'm thinking... We don't have tornadoes in CA I realize that all the trees have shifted and are bent the other way. EARTHQUAKE! The ground was moving and the tops of the trees weren't! We had a tug attached to the nose wheel. The tug tipped over and carved a seismogram along an arc as the plane turned 90 degrees. Peak amplitude was a good 30'. That's some ground movement for sure. Ten years later I was still startled into vigilance when an overpass of bridge moved and would not go into a parking deck. It takes a while to get over something seemingly that un-natural. My other big earthquake was years before LP in Tonga. Totally different geology. It was more like a sharp bang and the ground hitting our feet. The house shifted a little, the water tank fell over, and some dishes jumped off the wall.

I don't think it was the officers club. Waitress may not be the correct term. I'm referring to the young lady who rolled the burrito. Muy linda!

P wave is a compression wave that arrives sooner. S wave is a surface wave and the one that is usually felt. S wave has side to side component and vertical component. P wave gives very little warning. Less, the closer you are to the quake.

I spent a few years working on Nuclear Regulatory Commission funded research into reservoir induced seismicity. My job was instrumentation and telemetry. I managed to take some classes too.

 

I wonder if anyone took photos, I'll check with Ames history office. DC-8 or was it the Convair 990 (Galileo II)? I think you worked the tarmac when it was covered with NASA research aircraft instead of a couple Google planes nowadays.

 

As an Earth Scientist of 28 Yrs - I Agree

 

You have not looked at any of the papers we have on our website and now you pretend you know how it is wrong.

 

Uh uh. Blackouts are caused by consuming too much booze and drugs. I have done plenty of research on it, believe me.

 

Hm. Doesn't bode well for folks planning to use HF to get word out that they are ok in the event of a large quake. Preppers and the like.

 

In most cases emergency units would use NVIS (Near Vertical Incident Skywave) propagation which uses the troposphere and will not be attenuated as strong as skip.

Alex

 

Hi Alex. Well I guess that (NVIS) presents a host of other problems since the range for NVIS might get your signal just outside of the effected areas. Short of 'Field Day"..I wonder if anyone in the higher-risk areas have practice nets to get messages out? When we lose power up here in the Northeast, it's interesting to me to see just how many FM repeaters and nets still function as well as APRS gateways to get SMS messages out to friends & family. Point being I guess, is that few of us in this hobby prepare for real disaster preparedness. Anyway..the research you presented was certainly interesting to read and thought provoking in a number of directions! Cheers mate. -Warren

 

The statement that NVIS propagation uses the troposphere is incorrect. NVIS uses the same E and F regions as does low angle skip. NVIS relies on the frequency being low enough to refract high angle RF. The index of refraction in the troposphere is simply not high enough to refract low frequency RF. Carl K9LA

 

Nope. More misunderstanding of propagation and ionosphere. Troposphere (weather) has nothing to do with it. shakes head.

 

My mistake... it does use the ionosphere, but at lower frequencies in the area that can be covered is does not change much regardless of the state of the ionosphere. Signals below 10 MHz are very well reflected even when the solar flux is low.

 

That's wrong, as well. My local club in our hilly county does a test HF net every week using NVIS to communicate distances of ten to fifty miles or so, across ridges one to two thousand feet higher than us. We try three bands each week. The test is always at 6 pm local time. The ease of communication varies widely with the sunspot numbers, just as one would expect with any HF ionospheric propagation mode. It also varies with the seasons, partly because 6pm is well before sunset in the summer, and well after sunset in winter, and partly because the ionosphere recieves less solar radiation in winter.

40m is below 10MHz, and it is not always useful for NVIS. In times of low solar activity, we often find it useless for local communications, though sometimes, a helpful ham a few states away will relay messages for us.

 

Pseudoscience abounds...