Helicorder pattern

Please explain the helicorder pattern and what it may mean around the UTC 16:41.
Thank you!

Hello Mountains703,

It appears that around that time the Shake has recorded a very high (and also very local) vibration but after that (or during that) the power was lost and came back after it rebooted. If you have had a power cut, it is possible that the blank space in the recording was caused by that.