JA quake surface waves

Attached are three spectrograms of todays JA quake. Interesting (for me) is that the RS shows also the, what I believe is the surface waves arriving here in Europe.

The PLMA station is about 10 km from RD365 and the QLNO station is about 100 km away. All three stations are on the Ligurian coast, therefore, there are some ocean waves visible. Spectrograms are constant Q filtered.


Hello wmxz, and welcome back to the community!

It’s something that I also find interesting and am always looking for when larger quakes happen. Your surface wave arrivals match the same waveform I have detected on my Shake, and on all Shakes in Scotland, here:

Data in this image is lowpass filtered to 0.1 Hz, and waves start to appear visibly on all instruments around 8:00 UTC.

Great visual comparison between the data of your Shake and the data from the two other stations in Italy.