19Oct2021 10:28:45
An unusual earthquake generating a significant monotonic wave with a period around 7.5 seconds
The recording shows 30 minutes from seismometer G-FUTU on Futuna, about 808km from the earthquake epicentre.
The video is in plan view: north is up, south is down, west is left, east is right. the audio is west-east in the left channel, north-south in the right.
The top background trace is east-west, the lower north-south
The 30 minute recording is sped up 240 times.
Am I seeing phase rotation? Again?
The data was kindly provided by IRIS.
Turn it up.