There was a storm passing over Iceland. This has affected the tremor levels on IMO sensors. Mostly highland seismometers that get hit by stronger winds then those at lower altitude.
Volcano tremor appears differently at IMO sensors then wind noise and noise from ocean waves. But IMO sensors also pick those up at lower frequency bands (0.5 – 2Hz).
I had seen that and was wondering about it. Glad to know what was causing the rise in signal.