There were a couple of big quakes in the Philippines on the 13th at about 21.00. From what I can workout from the great Google, it should take about 12 minutes for the p-waves to travel the 11000km from there to my Shake in Spain. I’ve looked at my traces but I can’t work it out.
If some kind soul could spoon feed me this one thing then I’m sure I would be more self sufficient. My station is:
Ideally, I need someone to point to the spot on the trace and say “That’s an earthquake”. I’ve read lots but at my age I don’t think I’ll live long enough to learn this stuff
Yes, the first times it can be a bit frustrating trying to score around and around to find some traces that resemble the ones from an actual earthquake.
You can see how the P-wave arrives, when the vibrations immediately start from a “calm” background noise, and then the more high-amplitude S-waves arrive, just around 10 seconds later. You can use this as a reference, both the waveform and the spectrogram. If what you see resembles this, then it could likely be a quake.
Regarding the Philippines’ ones, I think that you are in, or very close by, at your distance, to the P-waves shadow-zone. This is an area where no P-waves will reach your seismometer, unless the earthquake is strong enough to allow detection of core waves from your location. The matter becomes a bit more complicated, but I’m sure these pages can get you started:
In any case, if a distant strong or major earthquake waves (let’s say from magnitude M6, 6.5 and above) reach your location, you will likely see high-amplitude waveform from the start of the event, like a wall rising up from the calm trace before it.
It looks pretty much like an earthquake … Checked surrounding RS devices, and most showed something but really not as big or clearly defined as I was seeing on mine. I almost wrote it off as something purely local. Then saw that there was a 7.3 earthquake just off the coast of Japan.
Checked the timing, and this is roughly in the right area. Not a nice clean P-S trace, but 7,500Km away, it is pretty likely that.
Yes, I got the Japan one too. The app is the game changer for me as you click on a quake and it takes you straight to the right point on your station. Then you can cross reference that with the browser version.
Yes, the app is good for that. I am hoping that some of that makes its way into the website version (DataView) one day – easier to read my Mac screen than my cellphone
