Ham Radio Earthquake Detection

Ham Radio Earthquake Detection

My father was a ham's ham. For nearly 50 years, Dad could be found in front of his trusty old Collins receiver almost every night. He worked a little sideband from time to time, and a little RTTY, but his real passion was CW. Dad was a Navy radio operator in the war, and he could easily copy faster than 40 WPM in his head, and even faster on a 'mill'.

A few years after I got my license, Dad called me into the shack one night. He pointed out the signals from a Southern California station. The signal was quite strong in our Bay Area home, but it had a strange 'echo' to it. It sounded identical to the multipath ringing that West Coast stations often hear on European signals coming over the pole.

Dad told me that he had noticed that ringing on many of the Southern California signals that night, on 80, 40, and even 20 meters. Then, Dad told me something a little strange. He told me that he had heard that same ringing on the signals from Alaska a couple of years earlier, the night before and shortly after the huge earthquake that flattened Anchorage and caused a tidal wave that killed people all the way down the coast to Northern California.

Further, he thought he had heard it on other occasions prior to earthquakes in other places on the West Coast, from Central America to the Aleutians.Dad had already made a note of it in his logbook, as he always did. The next morning, we awoke to the news of a major earthquake inSouthern California!

On one other occasion, Dad pointed out the ringing to me, on signals from Central America, and again, an earthquake soon followed.

Dad never said much about it. We encouraged him to report it to somebody, but he never did. I don't think he believed that he was the only one who noticed, but I think he might have been!I wish I could find his old logbooks so I could show the entries about 'ringing' and how they correlate to the actual quakes.This all happened over 30 years ago, though, so the logs are long gone, mostly lost in a housefire.

Since that time, I have brought this up on various forums, and I have been rewarded with a number of reports of similar things happening around the time of earthquakes. There has also been some serious scientific inquiry, which has shown that there is some connection between the quakes and multipath distortions.

I do not have any theories that would explain how multipath distortion of radio waves could be a precursor to tectonic activity. Perhaps it is somehow related to the increased discharge of ionized gasses from the area around quake sites that has been documented. All I know is that I have seen the phenomenon myself, and I have had a number of other reports.

I think Ham Radio operators can provide something here that the scientists can't easily reproduce. We can provide signals spaced over a wide geographical area and intelligent listeners who can hear unusual 'ringing' effects.

In order to help, you would first need to know what the signals sound like. Anyone who is familiar with the sound of HF signals coming over the pole at night knows what I am describing when I talk about 'watery' signals that are hard to copy. The ringing can be detected on both CW and SSB, though it is sometimes more obvious on CW signals. Any decent HF receiver capable of listening on the lower HF bands should do.

If you observe such a signal, what should you do? Do NOT call the press and announce a pending earthquake. That could and likely would make us all look foolish. But, I would suggest that you clearly document the the observation, perhaps including a recording of the signal. Then, watch carefully for earthquake reports in the hours after the observation. I would like to hear of both actual 'hits' and 'false alarms' - we need to know if this phenomenon is reliable or not.

Nearly all of the reports I've heard have revolved around the Pacific Coasts of both North and South America. However, there has also been some scientific interest in Europe, so I have to assume that this effect may exist elsewhere in the world.

Today, I think very few of us are as fortunate as my Dad, to be able to spend all our evenings doing what we love best, so it will take an effort by many of us to make this work. We need people on the air creating signals and many more people listening to them - in other words, increased activity on HF. Here's an opportunity for those 20,000 new Generals to participate in a scientific inquiry and a potentially great public service, while just hamming it up. Tell the XYL you can't drive the kids all over town because you are monitoring for earthquakes!

I would be happy to be a focal point for this activity. You can email me at wf0h@home.com.

Thanks and 73

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